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Broccoli stalk by-product (BsBP) is rich in glucosinolates (GSLs). Its fermentation process is generally characterized by the degradation of GSLs and formation of bioactive isothiocyanates (ITCs), in which lactic acid bacteria (LAB) play an important role. The GSLs-degrading capacity of 61 LAB strains was investigated in vitro. Lacticaseibacillus paracasei YC5, Pediococcus pentosaceus RBHZ36, and Lactiplantibacillus plantarum ND1, with high potential to transform GSLs into ITCs, were screened. The functional GSL degradation products (total content of sulforaphane, indol-3-carbinol, and ascorbigen) increased 22.0–33.5 % compared to natural fermentation after 24 h when BsBP was fermented by the three screened strains in pure culture. LAB fermentation also helped to increase the quantity of indolic GSL degradation products in BsBP brine, suggesting that LAB fermentation promoted BsBP GSLs transformation into bioactive ITCs. The proposed use of the LAB strains characterized in this study provided a fermented BsBP and brine with high profile of functional GSL degradation products. [Display omitted] • Broccoli stalk by-products (BsBPs) were fermented by LAB with GSLs transformation capacity. • Sulforaphane, indol-3-carbinol, and ascorbigen in BsBPs were enhanced by LAB fermentation. • Fermented BsBPs with a high profile of functional GSL degradation products were obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various Quorum sensing molecules was found in the stacking fermented grains. • AI-2/LuxS derived from LAB was a main driver of modifying microbial interaction. • Flavor synthesis of Maotai-flavor liquor was indirectly determined by AI-2. Stacking fermentation is typical process of Maotai-flavor Baijiu and microbial composition determine content of flavors. To date, the knowledge on the driving force of microbial composition was as yet unknown. Since quorum sensing molecule (QSM) plays an important role in modifying microbial interactions. Therefore, the objectives of the present study were: (1) to describe the microbial profile associated with QSM in stacking grains using metagenomics; (2) to elucidate how QSM shapes microbial interactions and accordingly regulates flavor synthesis. Results indicated that bacterial QSM including AI-2, DSF, and AHL as well as fungal QSM aromatic alcohols and farnesol were prevalent in the stacking fermented grains. Thereinto, AI-2 might be an important driving force of microbial composition due to its highest abundance. AI-2 in Limosilactobacillus fermentum , Pediococcus pentosaceus , and Weissella cibaria perhaps modified microbial interactions together with fungal QSM in Schizosaccharomyces pombe and Pichia membranifaciens. The role of AI-2 was much higher than that of fungal QSM. Furthermore, QSM indirectly influenced the synthesis of important flavors such as ethyl lactate, phenylethanol, and ethyl phenylacetate through the dynamic of microbial composition. Together, this current study for the first time explored the effects of QSM on microbial composition and flavor synthesis in the Baijiu field. [ABSTRACT FROM AUTHOR]

The high-temperature fermentation process of Daqu , a crucial ingredient in the production of Moutai -flavored Baijiu, is characterized by complex microbial interactions and differentiation at fermentation temperatures. This study is an investigation of the role that microbial cooperation and competition has in driving temperature differences during Daqu fermentation, using the results of real-time temperature monitoring, absolute quantitative amplicon sequencing, and microcalorimetry. The balanced interaction between the genera Pediococcus and Bacillus was observed to be a key factor in achieving high fermentation temperatures. The results indicated that the initial phase of fermentation is characterized by competition and niche differentiation, and that as fermentation proceeds, microbial community of the high-temperature Daqu tends to shift towards cooperation. Correlation network analysis revealed that on the 4th day of fermentation, Pediococcus and Bacillus formed distinct clusters with positive correlations within each cluster and significant negative correlation between them. The interaction and cohesion index analysis suggests that both genera play a crucial role in the high-temperature fermentation process of Daqu. Furthermore, simulated fermentation experiments confirmed that the coexistence of Pediococcus and Bacillus can enhance heat production in high-temperature environments than situations in which either genus dominates. These findings highlight the importance of the microbial community interaction in regulating fermentation temperature and provide valuable insights for optimizing the quality and consistency of Daqu fermentation products. [ABSTRACT FROM AUTHOR]

Cronobacter sakazakii is an opportunistic foodborne pathogen that can be fatal to infants; it is commonly associated with powdered infant formula due to contamination during manufacturing processes or during preparation in hospitals or homes. This project aimed to select a potential synbiotic, a combination of probiotic strains with a prebiotic product, to inhibit the growth of C. sakazakii in an in vitro dynamic infant gut model (Simulator of the Human Intestinal Microbial Ecosystem). A total of 16 lactic acid bacteria (LAB) were tested for their inhibitory properties against four different C. sakazakii strains by a zone of inhibition test. Lactobacillus and Pediococcus species were able to inhibit the growth (>15-mm inhibition zones) of all C. sakazakii strains tested, and only one strain from the two genera exhibited atypical resistance to tetracycline. All C. sakazakii strains and the selected LAB strains, which inhibited C. sakazakii and did not exhibit atypical antibiotic resistance, were grown in Luria-Bertani or de Man Rogosa Sharpe broth, respectively, containing 1% dextrose or 1% commercial prebiotic (w/v) to compare their ability to metabolize the prebiotic product. Overall, based on the growth inhibition of C. sakazakii, antibiotic susceptibility, and prebiotic metabolism, 6 of the 16 LAB were chosen to be part of a potential synbiotic. This study has provided valuable information that will help with the development of a synbiotic that can be used in powdered infant formula to reduce the potential for C. sakazakii–related illnesses in infants. Inhibition of C. sakazakii differed by genera and strains of LAB. Some Lactobacillus and Pediococcus strains grew better in the prebiotic substrate. Lactobacillus and Pediococcus grew better than C. sakazakii in the prebiotic. Some Lactobacillus and Pediococcus strains could be good candidates for use in a synbiotic. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of using different probiotic microorganisms in the composition of the synbiotic system fertilizer on microbial composition, nitrification process, and growth of Penaeus vannamei in the nursery phase. An intensive nursery was carried out (stocking density: 2000 shrimp m−3) for 40 days, using synbiotic fertilization protocols with different probiotic microorganisms in the following treatments: CW – clear water (control), B – Bacillus , BLP – Bacillus + Lactobacillus + Pediococcus , BLPY – Bacillus + Lactobacillus + Pediococcus + Yeasts (Saccharomyces cerevisiae), BY – Bacillus + Yeasts. In addition to probiotic, the fertilizer used rice bran as the main organic carbon source, molasses, sodium bicarbonate (as a buffer), and water in its composition. The Plankton community was analyzed by direct counting. The abundance of ammonia-oxidizing (AOB) and nitrite-oxidizing (NOB) bacteria were determined using fluorescent in situ hybridization. During the experimental time, a faster control of total ammonia nitrogen (TAN) was observed in BLP treatment. Throughout the trial, the control of nitrite through the nitrification process was not observed in the treatments where synbiotic systems were used. In these treatments, water changes were carried out to keep the concentration below the safe level for the species. The phytoplankton and zooplankton communities were basically dominated by Bacillariophyta and protozoans, respectively. On day 21 of the trial, BLP treatment had a higher abundance of AOB bacteria than CW, BLPY, and BY treatments. On day 39 of the experiment, BLP treatment had more NOB than BLPY and BY. Shrimp had a higher final weight in CW and BLP treatments than in the BY. Yield was higher in BLP, B, and BLPY treatments than in the CW. The use of Bacillus , Lactobacillus , and Pediococcus (BLP treatment) in synbiotic system fertilization promoted rapid control of TAN, a higher abundance of AOB and NOB, and improved shrimp growth performance in intensive nurseries. • Probiotic microorganisms in synbiotic improve ammonia control in shrimp nurseries. • Probiotic inoculation in shrimp nursery with synbiotic system increases AOB and NOB. • Probiotic inoculation improves growth and FCR in shrimp nurseries with synbiotic. [ABSTRACT FROM AUTHOR]

The characteristic aroma compounds of Chinese steamed bread (CSB) fermented with different starters were studied using HS-SPME-GC/MS, aroma recombination and omission experiments. The dynamic changes of the microbiota and their function and metabolites during fermentation were analyzed using metagenomics and non-targeted metabolomics. Forty-nine volatile flavor compounds were identified, while 5 characteristic aroma-active compounds were investigated in CSB fermented with commercial dry yeast (AQ-CSB), and 10 were investigated in CSB fermented with traditional starter (NY-CSB). Microbial structure and function analysis showed that Saccharomyces cerevisiae dominated during AQ-CSB fermentation and contributed >95% to its KEGG pathways, while Pediococcus pentosaceus , unclassified Pediococcus , Lactobacillus plantarum , Lactobacillus brevis and unclassified Lactobacillus were predominant in NY-CSB and together had an ~96% contribution to these pathways. NY-CSB showed higher metabolic activity during fermentation, and the characteristic metabolites were mainly involved in carbohydrate, amino acid and lipid metabolism. The characteristic aroma compounds were identified and increased the understanding of the contributions of the microbiota. This may be useful for designing starter cultures that produce CSB with desirable aroma properties. [Display omitted] • Five characteristic compounds were elucidated in CSB fermented with commercial yeast. • Ten characteristic aroma compounds were in CSB fermented with traditional starter. • The microbiota and their function during CSB fermentation were determined. • CSB fermented with traditional starter showed higher microbial co-occurrence. • Metabolites were due to carbohydrate, protein and lipid metabolism. [ABSTRACT FROM AUTHOR]

Probiotic bacteria have been well-known to provide health benefits to human beings. However, several harsh conditions have threatened their survival rate during processing, storage, and transit through the gastrointestinal tract (GIT). This study investigated the survivability of biofilm-producing Pediococcus pentosaceus encapsulated in calcium alginate gel beads (CAGBs) against harsh conditions. The present study successfully produced biofilms- in situ culture of P. pentosaceus in the CAGBs (CAGB-bio- situ). The subsequently formed biofilms showed high survivability to the GIT environment (50%–74%), refrigerator storage (88.6%), and pH 2 (30.7%). In addition, the Fourier transform infrared spectroscopy (FTIR) revealed that no new chemical bonds were formed between the sodium alginate and the bacterial cell. Furthermore, the water content of the CAGBs averaged 10.06%, which was considered acceptable. A single-step weight loss was observed in the thermogravimetric analysis (TGA) of CAGBs, while CAGB-bio- situ showed high thermal stability. Moreover, scanning electron microscopy (SEM) displayed bacteria aggregation on the beads surface in CAGB-bio- situ. As an alternative approach, this study speculates that the ability of P. pentosaceus to form biofilm would benefit from additional protection of CAGBs, which could serve as a fourth-generation approach to protect probiotics. [Display omitted] • Probiotic bacteria provide health benefits to human beings and their potent viability is worthy protecting. • Improving the survival of probiotic Pediococcus pentosaceus by using their ability to form biofilms combined with encapsulating materials i.e., Calcium alginate gel beads (CAGB). • Successful production of biofilms- in situ culture of P. pentosaceus in the CAGBs (CAGB-bio- situ). • Physicochemical properties of the calcium alginate beads containing biofilm-like structures. • Biofilm encapsulation provides a new insight into a protected process of probiotic delivery, which could serve as a fourth-generation approach to protect probiotics. [ABSTRACT FROM AUTHOR]

The application of matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS) as a technique for high-throughput characterization of microbiota in African traditional foods is limited. Kunu aya is an unexplored reservoir of protective lactic acid bacteria (LAB) strains. A total of 26 LAB isolates from kunu aya were identified using MALDI-TOF MS as five species, including Lactiplantibacillus plantarum (14) , Pediococcus pentosaceus (9) , Levilactobacillus brevis (1) , Lactiplantibacillus pentosus (1), and Weissella paramesenteroides (1). Antifungal activity screening of all LAB strains by agar-plate overlay assay revealed inhibition against Penicillium crustosum FOO5BA and/or Aspergillus flavus FOO8BA by six strains: L. plantarum (3) , Pd. pentosaceus (1) , L. brevis (1), and W. paramesenteroides (1). The six LAB strains demonstrated broad spectrum antifungal activity, when tested against eight molds from plant-based foods, inhibiting 4 to 7 molds, with average inhibition scores (AIS) of 0.75–2.75. L. brevis MKAIA1b showed the strongest antifungal activity (AIS; 2.75). Agar diffusion method revealed that antifungal activity against all target molds was retained in cell-free supernatants of L. brevis MKAIA1b, with the highest inhibition demonstrated against P. citrinum 3AS1 (15.34%). In challenged kunu aya fermented with L. brevis MKAIA1b or L. brevis MKAIA1b and L. plantarum TMP051, the growth of A. flavus F008BA, Fusarium langesthiae 13,014, and P. crustosum FOO5BA was delayed beyond 7 days at ambient temperature (25 °C). In this study, MALDI-TOF MS was an effective tool to reveal the species composition of LAB in kunu aya, which harbors LAB strains that displayed strong antifungal activity, while showing great potentials as a protective culture and for bio-control. [ABSTRACT FROM AUTHOR]

Gluten-free (GF) baked goods available in the market are often poor in nutrients, such as protein, dietary fibre, micronutrients and bioactive compounds, and have low technological quality. Therefore, it is important to develop GF products with nutrient-rich flours, like quinoa (Q) and buckwheat (BW). Sourdough (SD) technology generates desirable nutritional and technological effects to improve GF bread. The objective of this work was to evaluate the effect of four autochthonous strains of lactic acid bacteria used as sourdough starters on the nutritional and technological quality of GF breads made with non-conventional flours. Lactiplantibacillus plantarum T3 , Limosilactobacillus fermentum T4 , Pediococcus acidilactici 26 and Pediococcus pentosaceus 82 were isolated in Q and BW flours. Nutritional and technological properties of flours, SD and breads were evaluated. In Q SD and breads, there was a 90% increase of polyphenols, 36% of ferulic acid and 131% in antioxidant capacity with respect to control compared to BW. In Q BW SD and breads, there were higher amounts of free amino acids and lower phytic acid content compared to SD controls. The incorporation of SD increased the specific volume, reduced the initial firmness of the crumb and the rate of hardening, produced a darkening of the crust; the crumbs of the breads were spongier, with a greater fraction of air and quantity of alveoli. Breads with Q SD presented better technological quality than breads with BW SD. Lim. fermentum T4 and P. pentosaceus 82 produced SD and breads with better technological quality. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) are frequently used in meat fermentation, and mixed stater cultures are reported to perform better than single ones. Lactiplantibacillus plantarum 3-19 and Pediococcus pentosaceus 18-1 were chosen from 28 sour-meat-origin strains to examine the effects of single and combined inoculation on sour meat quality. Natural fermentation was used as a control to investigate changes in pH, water activity (a w), amino acid nitrogen (AN), texture, microbial diversity, and volatile organic compounds (VOCs) during fermentation. The pH and a w of each inoculation group were significantly decreased, and AN content was significantly increased. The inoculation of P. pentosaceus 18-1 significantly reduced putrescine, cadaverine, and tryptamine content (p < 0.05), while the inoculation of Lpb. plantarum 3-19 significantly reduced cadaverine amounts (p < 0.05). At the fermentation endpoint, the total biogenic amines content in the C group was 992.96 ± 14.07, which was 1.65, 2.57, and 3.07 times higher than that in the Lp, Pe, and M groups, respectively. The mixed inoculation group combined the advantages of both strains and decreased total biogenic amines most significantly. At the end of fermentation, the VOCs in C, Lp, Pe, and M groups were 10.11, 11.56, 12.45, and 13.39 times higher than those at the beginning of fermentation. Inoculation promoted the production of key VOCs (OAV > 2000) such as heptanal, octanal, and (E)-2-nonanal. The mixed inoculation group had the highest variety and content of VOCs and the highest content of the above key VOCs, significantly enhancing its fruity, floral, ester, and other aromas. Sensory evaluation indicated that the M group had the best overall acceptability. Finally, it was suggested that a combination of Lpb. plantarum 3-19 and P. pentosaceus 18-1 is a novel and efficient starter culture for processing sour meat since they lower the amounts of biogenic amines in the meat and promote the production of VOCs. • Inoculation affects the microbial composition in sour meat. • Mixed stater culture reduced biogenic amine accumulation more efficiently. • Mixed stater cultures significantly increase the contents of volatile organic compounds in sour meat. [ABSTRACT FROM AUTHOR]

[Display omitted] • High antioxidant activity was observed in lacto-fermented garlic. • Volatilome analysis showed the dominance of sulfur compounds and alcohols. • Lacticaseibacillus, Levilactobacillus, Lactiplantibacillus were the major taxa. • Good acidification performance was observed for the lactic acid bacteria isolates. • In-vitro exopolysaccharides production was observed for a few isolates. The aim of the present study was to provide a first characterization of lacto-fermented garlic manufactured by local small-scale artisanal producers in the Lower Silesia Region (Poland). The lacto-fermented garlic samples showed high nutritional features in terms of antioxidant activity. A total of 86 compounds, belonging to various chemical classes, were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS). Most of these compounds belonged to six main classes, being sulfur compounds, esters and acetates, oxygenated monoterpenes, monoterpene hydrocarbons, and alcohols. Aldehydes, acids, ketones, furans, and phenols were also identified. In the analyzed samples, counts up to 8 log cfu g−1 were observed for lactic acid bacteria. Metataxonomic analysis revealed the presence of Levilactobacillus , Lactiplantibacillus , Latilactobacillus , Secundilactobacillus , Weissella , Leuconostoc , Lactococcus , Pediococcus , and Lacticaseibacillus among the major taxa. These results were confirmed by the isolation and characterization of viable lactic acid bacteria. Indeed, the presence of the closest relatives to Lacticaseibacillus casei group, Pediococcus parvulus , Levilactobacillus brevis , Levilactobacillus parabrevis , and Lactiplantibacillus plantarum group was observed. A good acidification performance in salty garlic-based medium was observed for all the isolates that, between 8 and 15 days of fermentation, reached pH values comprised between 4 and 3.5, depending on the tested species. Of note, 15 out of the 37 lactic acid bacteria isolates (Levilactobacillus parabrevis , Pediococcus parvulus , Lactiplantibacillus plantarum group, and Lacticaseibacillus casei group) showed the presence of the hdcA gene of Gram-positive bacteria encoding for histidine decarboxylase. Furthermore, for 8 out of the 37 isolates the in-vitro exopolysaccharides production was observed. No isolate showed inhibitory activity against the three Listeria innocua strains used as surrogate for Listeria monocytogenes. [ABSTRACT FROM AUTHOR]

[Display omitted] • P. pentosaceus ZZ61 enhances growth performance of the economic insect silkworm. • P. pentosaceus ZZ61 protects the silkworm against pathogenic infection. • P. pentosaceus ZZ61 affects the silkworm gut microbiota. • The shifts of gut microbiota by ZZ61 further alters the levels of gut metabolites. Probiotics have attracted considerable attention in animal husbandry due to their positive effect on animal growth and health. This study aimed to screen candidate probiotic strain promoting the growth and health of silkworm and reveal the potential mechanisms. A novel probiotic Pediococcus pentosaceus strain (ZZ61) substantially promoted body weight gain, feed efficiency, and silk yield. These effects were likely mediated by changes in the intestinal digestive enzyme activity and nutrient provisioning (e.g., B vitamins) of the host, improving nutrient digestion and assimilation. Additionally, P. pentosaceus produced antimicrobial compounds and increased the antioxidant capacity to protect the host against pathogenic infection. Furthermore, P. pentosaceus affected the gut microbiome and altered the levels of gut metabolites (e.g., glycine and glycerophospholipids), which in turn promotes host nutrition and health. This study contributes to an improved understanding of the interactions between probiotic and host and promotes probiotic utilization in sericulture. [ABSTRACT FROM AUTHOR]

This study isolated and identified autochthonous lactic acid bacteria (LAB) from mandacaru fruit and evaluated their potential probiotic and technological aptitudes in vitro , as well as the protective effects of freeze-dried mandacaru fruit on the most promising LAB isolate during lyophilization and refrigeration storage. Initially, 212 colonies were isolated from mandacaru fruit, and 34 were preliminarily identified as LAB. Thirteen isolates identified by 16S-rRNA sequencing as Pediococcus pentosaceus were negative for DNase, gelatinase, hemolytic, and biogenic amine production. The selected isolates showed proteolytic activity, diacetyl and exopolysaccharide production, and good tolerance to different NaCl concentrations while having low cellular hydrophobicity and antagonistic activity against pathogens. The survival of isolates sharply decreased after 3 h of exposure to pH 2 and had a good tolerance to 1 % bile salt. A principal component analysis selected P. pentosaceus 57 as the most promising isolate based on the examined technological and probiotic-related physiological properties. This isolate was lyophilized with mandacaru fruit and stored under refrigeration for 90 days. P. pentosaceus 57 lyophilized with mandacaru fruit had high viable cell counts (9.69 ± 0.03 log CFU/mL) and >50 % of physiologically active cells at 90 days of refrigeration storage. The results indicate that mandacaru fruit is a source of P. pentosaceus with aptitudes to be explored as potential probiotic and technological characteristics of interest for the food industry, besides being a good candidate for use in lyophilization processes and refrigeration storage of LAB due to its cryoprotective effects. • Mandacaru fruit is a source of lactic acid bacteria (LAB) with probiotic potential probiotic. • 16S-rRNA sequencing analysis identified LAB isolates as Pediococcus pentosaceus. • Mandacaru fruit protected P. pentosaceus during lyophilization and refrigeration storage. • Mandacaru fruit decreased damage in lyophilized P. pentosaceus 57 cells. [ABSTRACT FROM AUTHOR]

Daqu provides microbiota, flavor substances and enzymes for liquor fermentation. Storage after fermentation is an essential stage for the mature of Daqu. However, it is still unclear about the effect of storage on the microbiota structure and enzyme profile. Here, this work revealed the variation of microbiota structure and enzyme profile after storage of low-temperature Daqu using amplicon sequencing and proteomic profile analysis. Results showed that the content of acidity significantly increased by 13.79% (P ＜0.05). The saccharification power, liquefaction power and fermentation power significantly increased by 2.90%, 17.32% and 16.04%, respectively (P ＜0.05). The contents of 3-methyl-1-butanol and 1-octen-3-ol increased by 147.19% and 29.12%, respectively (P ＜0.05). Lichtheimia , Saccharomyces , Rhizopus , Aspergillus , Pantoea , Lactiplantibacillus , Pichia , Lacticaseibacillus , Pseudomonas , Linnemannia , Levilactobacillus , Pediococcus , Paenibacillus and Lactobacillus were the major enzyme-producing microbiota (average protein abundance >1%) using proteomic profile analysis. After storage, the relative abundances of Lactobacillus and Aspergillus increased from 2.59% to 17.63%, and 7.53%–33.67% using amplicon sequencing, respectively. The protein abundance of α-amylase produced by Aspergillus increased from 0.05% to 0.11%, and was consistent with variations of the relative abundance of Aspergillus , and the liquefaction power. The protein abundance of lactic acid dehydrogenase produced by Lactobacillus increased from 0.07% to 0.11%, and was consistent with the variation of relative abundance of Lactobacillus. This work revealed the effect of storage on microbioa and enzyme proteomic profile of low-temperature Daqu. It would be beneficial for controlling the storage stage of Daqu , and help improving the quality of Daqu. [Display omitted] • The variations of core microbiota were analyzed after storage. • The variations of enzymes associated with starch degradation were analyzed. • The variations of enzymes associated with key flavor substances were analyzed. [ABSTRACT FROM AUTHOR]

Pediococcus pentosaceus has a promising potential to improve the quality and flavor of Chinese steamed bread (CSB), but its synergistic effect with Saccharomyces cerevisiae is still unclear. In this study, P. pentosaceus was cocultured with three S. cerevisiae isolates separately, which had different leavening ability. The times required for the fermentation of dough by 2 times the volume of S. cerevisiae isolates ACX 0089, ACX 0490 and ACX 0078 were 46, 88 and 120 min, respectively. The results showed that the leavening ability of S. cerevisiae had a significant impact on the quality of CSBs. Compared other S. cerevisiae isolates, the ACX 0490 cocultured with P. pentosaceus increased the contents of bound water and free water in CSB, decreased the content of semibound water, and produced larger and regular porosity, thus endowed a greater specific volume and softer texture. A total of 36 volatile organic compounds (VOCs) were found in CSBs, with alcohols accounting for the main component. The coculture of P. pentosaceus with the intermediate leavening ability of S. cerevisiae ACX 0490 produced the highest proportion of esters among all CSBs. Moreover, S. cerevisiae ACX 0490 endowed the CSB unique VOCs, including cyclodecanol, ethylacetate, and 3,5-dimethylbenzaldehyde. The results of sensory evaluation also showed that S. cerevisiae ACX0490 cocultured CSB obtained the highest scores among all the test samples. The results provided a reference for selecting S. cerevisiae isolates with different leavening ability and the combination of P. pentosaceus to achieve the best quality and flavor of CSB. [Display omitted] • The quality and flavor of CSB cocultured by P. pentosaceus and S. cerevisiae with different leavening ability were compared. • The hardness of CSB cocultured by S. cerevisiae ACX0490 was the lowest. • The contents of volatile esters in CSBs cocultured by S. cerevisiae ACX 0490 were the highest. • CSB cocultured by S. cerevisiae ACX 0490 and P. pentosaceus had the best sensory quality. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effect of alginate and inulin-based microencapsulation on the viability of Lactiplantibacillus plantarum HL4 and Pediococcus parvulus HL14 in sauerkraut. Sauerkraut maintianed the desired microencapsulated cell count (>6 log CFU/g) until the sixth week of storage. At the end of storage, MSL (samples containing L. plantarum HL4) had the highest total phenolic content (2536.50 mg GAE/L). However, at the end of storage, MSL and MSP (samples containing P. parvulus HL14) showed the highest DPPH value of 71.67% and 62.26% and ABTS+ value of 95.68% and 94.08%, respectively. The highest general assessment scores were achieved by samples containing L. plantarum HL4 and P. parvulus HL14. Consequently, the microcapsules demonstrated a protective effect on the strains, particularly P. parvulus. Furthermore, the strains have a high potential for sauerkraut production enriched with presumptive probiotics, and the final product could be acceptable to consumers. • Presumptive probiotics were encapsulated with high efficiency. • The survival of presumptive probiotics in sauerkraut was enhanced by microencapsulation. • MSL had the highest total phenolic content at the end of the storage. • MSL exhibited the highest antioxidant activity at the end of the storage. • Sauerkraut samples containing presumptive probiotics were sensorially acceptable. [ABSTRACT FROM AUTHOR]

As a valuable aromatic alcohol, 2-phenylethanol has been widely used in the fields of food, medicine and chemistry, but its production has become a key factor limiting microbial industrialisation. Therefore, atmospheric and room temperature plasma (ARTP) mutagenesis was applied to improve host cell tolerance of 2-phenylethanol, and 2-phenylethanol production was increased from 2.23 g/L to 2.51 g/L in Kluyveromyces marxianus. Fermentation conditions of K. marxianus and Pediococcus lactis co-culture were optimised and production of 2-phenylethanol was further increased by 42.63%, reaching 3.58 g/L. Metabonomics analysis revealed that the cell wall of P. lactis could effectively activate Ehrlich pathway-related metabolism and upregulate arginine synthesis pathways to enhance the cellular robustness of K. marxianus , thereby improving the efficiency of 2-phenylethanol synthesis, and providing a novel strategy for cost-effective 2-phenylethanol production. [Display omitted] • ARTP mutagenesis improves cellular tolerance of 2-phenylethanol. • The interaction between P. lactis and K. marxianus is elucidated. • The cytoderm of P. lactis enhanced the utilization of l -phenylalanine. • Production of 2-phenylethanol was increased to 3.58 g/L. [ABSTRACT FROM AUTHOR]

In present study, we investigated the probiotic potential of three Pediococcus spp. isolated from Iranian traditional fermented cereal-dairy product, Tarkhineh. These 3 strains were identified as Pediococcus acidilactici VKU2, P. acidilactici IAH-5 and P. pentosaceus DHR005 by 16S rRNA gene sequencing. All the strain were found tolerate to pH 3 and 0.3% oxall for 3 h as well as simulated gastric and intestinal juice. P. acidilactici IAH-5 showed the highest cholesterol removal (67.52%), hydroxyl radical scavenging activity (58.32%), hydrophobicity (40.3%) and auto-aggregation (48%). Pediococcus spp. inhibited the growth of tested pathogens (Escherichia coli ATCC 25922, Pseudomonas aeruginosa PTCC 1707, Salmonella typhimurium PTCC 1609, and Staphylococcus aureus ATCC 25923) which the most susceptible strain was S. aureus. In competition assay, P. acidilactici IAH-5 was able to inhibited adhesion of 67.3% of S. typhimurium and in inhibition assay 45.8% of the pathogenic adhesion to Caco-2 cells were decreased. P. acidilactici VKU2 and P. acidilactici IAH-5 showed 16.32 and 12.25% adhesion to simulated epithelial cell line which were also confirmed by scanning electron microscopy. Pediococcus spp. did not showed DNase production or hemolytic activity which confirm its safety aspects. Our findings suggested that the P. acidilactici IAH-5 has the best properties with probiotic features and cholesterol assimilation for its application as novel bio-therapeutic and bio-preservation agents. [ABSTRACT FROM AUTHOR]

Probiotic microorganisms are a promising alternative to antibiotics in preventing and treating bacterial infections. Within the probiotic group, the lactic acid bacteria (LAB)stand out for their health benefits and for being recognized as safe by regulatory agencies. However, these microorganisms are sensitive to various environmental conditions, including the acidic environment of the stomach. Faced with these obstacles, this work aimed to promote the symbiotic microencapsulation of LAB in a composite matrix of alginate and prebiotics to enhance their survival and improve their probiotic activity during gastrointestinal transit. We evaluated the effect of inulin, fructo-oligosaccharides (FOS) and mannan-oligosaccharides (MOS) as prebiotic sources on the growth of Pediococcus pentosaceus LBM34 strain, finding that MOS favored LAB growth and maintenance of microencapsulated cell viability. The symbiotic microparticles were produced using the spray-drying technique with an average size of 10 μm, a smooth surface, and a composition that favored the stabilization of live cells according to the FTIR and the thermal analysis of the material. The best formulation was composed of 1 % of alginate, 10 % MOS and 1 % M10 (% w/v), which presented notable increases in the survival rates of the probiotic strain in both alkaline and acidic conditions. Therefore, this industrially scalable approach to symbiotic LAB microencapsulation can facilitate their growth and colonization within the host. This effort aims to contribute to reducing antibiotic reliance and mitigating the emergence of new zoonotic diseases, which pose significant challenges to public health. [Display omitted] [ABSTRACT FROM AUTHOR]

Two experiments, 1 in vitro and 1 in vivo study, were conducted to analyze probiotic species characteristics and survival in the intestine of broiler birds. The in vitro study characterized the effect of bile salt supplementation and pH on the proliferation of Lactobacillus reuteri, Pediococcus acidilactici, Bifidobacterium animalis , and Enterococcus faecium. L. reuteri and P. acidilactici growth was maximal when the media was supplemented with 1.0% bile salt, whereas B. animalis and E. faecium growth was maximal when the media was supplemented with 0.5% bile salt. Altering the pH between 2.5 and 5.8 did not significantly (P > 0.05) alter the proliferation of L. reuteri and B. animalis. Decreasing the pH from 5.8 to 2.0 decreased P. acidilactici growth, whereas it increased the E. faecium proliferation. The in vivo study quantified the concentration of L. reuteri, P. acidilactici, B. animalis, E. faecium , and L. salivarius in different intestinal sections from birds supplemented with and without synbiotic containing the above 5 bacteria species. Birds were supplemented with and without synbiotic for 18 d, after which all birds were fed the same basal diet with no synbiotic. At 72 h of feeding, the basal diet with no synbiotics, when the probiotic species in the feed is expected not to confound the recovery of probiotic species from the intestine, intestinal contents were collected. L. reuteri, P. acidilactici, E. faecium , and L. salivarius were below detectable amount in the control group. L. reuteri concentration expressed as copy numbers/g and as percentage of total bacteria was highest in the jejunum and ileum, respectively. E. faecium concentration was highest in the ileum. The copy number of P. acidilactici increased at the duodenum and plateaued after duodenum. L. salivarius concentration was highest in the jejunum. It can be concluded that real-time PCR can be applied to quantify the concentrations of probiotic species in the intestine and probiotic species differ in their ability to colonize different sections of the intestine. [ABSTRACT FROM AUTHOR]

This study investigated the purification and biochemical characteristics of the protease produced by Pediococcus pentosaceus isolated from Harbin dry sausages. The optimized fermented conditions were as follows: fermentation time 36 h, initial pH 5 and fermentation temperature 30 °C. A 29.6 kDa extracellular protease was purified using ammonium sulphate deposition, ion exchange layer system and gel filtration. The protease produced by P. pentosaceus had a certain pH and thermal stability at pH 6 and 30 °C. The microbial protease activity could be inhibited by ethylene diamine tetraacetic acid disodium salt (EDTA). V max and K m of the protease were 43.9 mg/min and 8.3 mg/mL, respectively. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) reflected the ability of the protease to hydrolyse sarcoplasmic and myofibrillar proteins, particularly those of myosin heavy chain, paramyosin, actin, phosphorylase and creatine kinase-M types. 3D structure modelling of the P. pentosaceus protease found two domains in the protease protein and the correlation of the active sites with protease properties and substrate specificity. In conclusion, P. pentosaceus can be used as a starter culture or enzyme producing strain for inoculation in Harbin dry sausages. • Fermentation conditions were optimized for the protease production from strain. • Enzymatic properties of the purified protease were investigated. • P. pentosaceus protease can hydrolyse myofibrillar and sarcoplasmic protein. • P. pentosaceus protease structures were simulated by homology modelling. [ABSTRACT FROM AUTHOR]

The interest towards legumes in food applications has risen over the past decades. However, the presence of antinutritional factors (ANF) and the poor technological performances still restricts their application in food fortification. In this study, four lactic acid bacteria (LAB) isolated from faba bean were applied as starter cultures for faba bean bioprocessing. None of the strains employed produced exopolysaccharides from raffinose, on the contrary, they did with sucrose as substrate. The fermented doughs were characterized and the strains were compared for their adaptation capacity and metabolic performance including the formation of dextrans, the degradation of ANF and the ability to improve antioxidant activity and in vitro protein digestibility (IVPD). A contribution to the proteolysis was given by the presence of endogenous enzymes, responsible for the increase of peptides and amino acids in dough from irradiated flour. However, the LAB strains further enhanced proteolysis. Weissella cibaria VTT E-153485 led to the highest peptide release and consequentially to the highest IVPD. In doughs fermented with Pediococcus pentosaceus VTT E-153483 and Leuconostoc kimchi VTT E-153484, phytic acid was reduced to more than half the initial concentration. Inoculated doughs had significantly lower content of oligosaccharides after 24 h of incubation compared to the controls. The most efficient raffinose consumption was found for Leuc. kimchi and W. cibaria. Doughs inoculated with weissellas contained >1% of dextrans. Weissella confusa VTT E-143403 induced a significant increment in viscosity (ca. 7 times higher than the controls). This study revealed that well-characterized, indigenous LAB provided beneficial biotechnological features in faba bean dough processing and contributed to its implementation in the food production. [ABSTRACT FROM AUTHOR]

Type 3 sourdoughs, which are starter culture-initiated and subsequently backslopped, are less studied than other sourdough types. Yet, they can serve as a model to assess how competitive starter culture strains for sourdough production are and how the microbial composition of such sourdoughs may evolve over time. In the present study, Limosilactobacillus fermentum IMDO 130101 was used to produce Type 3 sourdoughs, prepared from wheat and wholemeal wheat flours. Therefore, an initial fermentation of the flour-water mixture was performed at 30 °C for 48 h. This was followed by cold storage-backslopping cycles, consisting of refreshments (50 %, v/v), fermentation steps of 16 h, and storage at 4 °C each week, every three weeks, and every six weeks. The microbial dynamics (culture-dependent and -independent approaches) and metabolite dynamics were measured. In all sourdoughs produced, starter culture strain monitoring, following an amplicon sequence variant approach, showed that Liml. fermentum IMDO 130101 prevailed during one month when the sourdoughs were refreshed each week, during 24 weeks when the sourdoughs were refreshed every three weeks, and during 12 weeks when the sourdoughs were refreshed every six weeks. This suggested the competitiveness and robustness of Liml. fermentum IMDO 130101 for a considerable duration but also showed that the strain is prone to microbial interference. For instance, Levilactobacillus brevis and Pediococcus spp. prevailed upon further cold storage and backslopping. Also, although no yeasts were inoculated into the flour-water mixtures, Kazachstania unispora , Torulaspora delbrueckii , and Wickerhamomyces anomalus were the main yeast species found. They appeared after several weeks of storage and backslopping, which however indicated the importance of an interplay between LAB and yeast species in sourdoughs. The main differences among the mature sourdoughs obtained could be explained by the different flours used, the refreshment conditions applied, and the sampling time (before and after backslopping). Finally, the metabolite quantifications revealed continued metabolite production during the cold storage periods, which may impact the sourdough properties and those of the breads made thereof. • Limosilactobacillus fermentum is a robust sourdough starter culture. • The amplicon sequence variant approach is a powerful tool to closely monitor this starter culture strain. • Cold storage-backslopping cycles influenced the appearance of yeasts. • The sourdough metabolites were mainly influenced by the flour type. • Metabolite production occurred mainly during initial fermentation and cold storage. [ABSTRACT FROM AUTHOR]

[Display omitted] In the present study, naturally fermented and unpasteurized cucumbers (Cucumis sativus L.) collected from 4 producers located in different regions of Poland were studied. The fermented cucumbers were characterized by significant nutritional features in terms of polyphenols content and antioxidant activity. Microbiological analyses revealed active bacterial populations of lactococci, thermophilic cocci, lactobacilli, and coagulase-negative cocci. The microbiological characterization of cucumber and brine samples through metataxonomic analysis allowed the dominant species to be detected, being Lactococcus and Streptococcus in cucumbers, and Lactiplantibacillus , Leuconostoc , Pediococcus , Secundilactobacillu s, and Lentilactobacillus in brine. The isolation activity offered a clear picture of the main active lactic acid bacteria at the end of fermentation, being Pediococcus parvulus and Lactiplantibacillus plantarum group. All the studied isolates showed a good attitude in fermenting a cucumber-based broth, thus suggesting their potential application as starter or adjunct cultures for guided cucumber fermentation. Moreover, for the same isolates, strong aminopeptidase activity (due to leucine arylamidase and valine arylamidase) was observed, with potential effect on the definition of the final sensory traits of the product. Only a few isolates showed the ability to produce exopolysaccharides in synthetic medium. Of note, the presence of the hdcA gene in some Pediococcus ethanolidurans isolates also confirmed the need for a thorough characterization of starter candidates to avoid undesired adverse effects on consumer's health. No isolate showed the production of bacteriocins against Listeria innocua used as surrogate for Listeria monocytogenes. Based on the results of Headspace Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry analysis, a rich and complex volatilome, composed by more than 80 VOCs, was recognized and characterized. In more detail, the detected compounds belonged to 9 main classes, being oxygenated terpenes, alcohols, terpenes, ketones, acids, aldehydes, esters, sulfur, and sesquiterpenes. [ABSTRACT FROM AUTHOR]

Sourdough starters harbor microbial consortia that benefit the final product's aroma and volume. The complex nature of these spontaneously developed communities raises challenges in predicting the fermentation phenotypes. Herein, we demonstrated for the first time in this field the potential of genome-scale metabolic modeling (GEMs) in the study of sourdough microbial communities. Broad in-silico modeling of microbial growth was applied on communities composed of yeast (Saccharomyces cerevisiae) and different Lactic Acid Bacteria (LAB) species, which mainly predominate in sourdough starters. Simulations of model-represented communities associated specific bacterial compositions with sourdough phenotypes. Based on ranking the phenotypic performances of different combinations, Pediococcus spp. – Lb. sakei group members were predicted to have an optimal effect considering the increase in S. cerevisiae growth abilities and overall CO 2 secretion rates. Flux Balance Analysis (FBA) revealed mutual relationships between the Pediococcus spp. – Lb. sakei group members and S. cerevisiae through bidirectional nutrient dependencies, and further underlined that these bacteria compete with the yeast over nutrients to a lesser extent than the rest LAB species. Volatile compounds (VOCs) production was further modeled, identifying species-specific and community-related VOCs production profiles. The in-silico models' predictions were validated by experimentally building synthetic sourdough communities and assessing the fermentation phenotypes. The Pediococcus spp. – Lb. sakei group was indeed associated with increased yeast cell counts and fermentation rates, demonstrating a 25 % increase in the average leavening rates during the first 10 fermentation hours compared to communities with a lower representation of these group members. Overall, these results provide a possible novel strategy towards the de-novo design of sourdough starter communities with tailored-made characterizations, including a shortened leavening period. • Genome-scale metabolic modeling well-predicted sourdough fermentation phenotypes. • Pediococci and Lb. sakei were correlated with a 25 % increase in leavening rate. • Nutritional bidirectional dependencies and competition shape microbial consortia. • Species and community-related VOCs production patterns were in-silico observed. • The study suggests a novel approach towards tailored sourdough starter communities. [ABSTRACT FROM AUTHOR]

Dry aging is a historic and common-used preservation and increment method for meat processing, giving the meat product unique mouthfeel and attracted flavor. In this work, less time-consuming intensified dry aging was conducted by using specified strains (all selected from "List of Strains Allowed to Be Used in Food" issued by National Health Commission of the People's Republic of China) mixed of Staphylococcus sarcosa , Debaryomyces hansenii and Pediococcus pentose (1:1:1). The taste, aroma, texture and microbiota of intensified dry-aged beef were investigated and correlatively analyzed. Results showed that the contents and varieties of main taste and aromatic compounds in final products were significantly increased by intensified dry aging, along with unique texture formation and improved palatability of beef. Most importantly, the above-mentioned quality changes were confirmed to be closely correlated with microbial succession during fermentation. All the 3 strains had extremely significant positive correlations with springiness, and Debaryomyces hansenii positively correlated with taste components, and both Pediococcus and Debaryomyces had significant positive correlations with volatile flavor substances. Additionally, 3 selected strains for intensified dry aging could inhibit the growth of spoilage organisms to an extent. This work provides valuable reference both for the industrialization and standardization of dry-aged meat products. • Staphylococcus sarcosa , Debaryomyces hansenii and Pediococcus pentose (1:1:1) were firstly applied to intensified dry aging. • Debaryomyces hansenii had a great influence on increasing the taste components. • Both Pediococcus and Debaryomyces had significant positive correlations with volatile flavor substances. • All the 3 strains were positive to the formation of unique texture of intensified dry-aged beef. • The selected 3 strains could inhibit the growth of spoilage organisms to an extent. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Sijunzi decoction (SJZD) is a classic recipe in traditional Chinese medicine (TCM) to strengthen the spleen and replenish Qi. It is well known for treating disorders of gastrointestinal function manifested in poor appetite, reduced food intake and loose stools. Polysaccharide is the most abundant constituent and the major effective component in SJZD. Aim of the study The present study aimed to understand the immunomodulatory mechanism of S-3–1, a homogeneous polysaccharide purified from SJZD with immune-enhancement activity, by investigating its effects on human intestinal microbes and short chain fatty acids. Materials and methods S-3–1 was incubated with simulated gastric juice, intestinal juice, and human fecal microflora independently and sequentially. The concentrations of total polysaccharide and reducing sugar were measured to identify the stability of independently and sequentially incubated S-3–1 in three in vitro fermentation models. Gas chromatograph (GC) analysis was used to measure the short chain fatty acid (SCFA) contents in human fecal samples. The human gut microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region). Results S-3–1 was degraded in three in vitro fermentation models separately and sequentially. Both S-3–1 and incubated S-3–1 could regulate the abundances of Lactobacillus , Pediococcus , Streptococcus , Bacteroides , Enterococcus , Clostridium and Dorea in human intestinal microflora samples. Specifically, S-3–1 could only regulate the abundances of Paraprevotella and Oscillospira , while the influenced flora changed to Butyricimonas , Coprococcus , Dialister , Sutterella , Ruminococcus and Parabacteroides after sequential incubation of S-3–1. In contrast to S-3–1 showing no influence on the content of SCFA, incubated S-3–1 showed increased contents of acetic acid and total acid that were associated with its effects on the abundances of Enterococcus , Sutterella , Butyricimonas and Streptococcus . Conclusion S-3–1 plays an immunomodulatory role by regulating the abundances of 9 intestinal bacteria genera. Incubated S-3–1 can regulate more bacteria genera, a total of 13 kinds, and can adjust the SCFA content to affect immunomodulation. Incubation with gastric and intestinal juices enhanced S-3–1′s capability of modulating the intestinal flora composition and decreased the bacteria’s need for a carbon source. This study could provide new insights for studies on the pharmacological mechanisms of polysaccharides in vitro . [ABSTRACT FROM AUTHOR]

The major reduction in probiotic viability that occurs during food storage and gastrointestinal transit limits their potential health benefits. Microencapsulation is one of the most effective methods to protect probiotics from various harsh conditions. In this study, a model probiotic ( Pediococcus pentosaceus Li05) was encapsulated in an alginate-gelatin microgels in the absence and presence of magnesium oxide (MgO) nanoparticles (NPs). The morphology and surface properties of the encapsulation systems were characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM), which showed that both the probiotics and NPs were successfully incorporated into spherical microgels. The viability of the probiotic was evaluated after exposure to different conditions: long-term storage in an aerobic environment; heat treatment; and gastrointestinal transit. Encapsulation of the probiotics significantly enhanced their viability under these different conditions. Probiotics encapsulated in MgO-loaded microgels were more stable than free bacterial cells or those encapsulated in microgels alone: less than 2 log 10  CFU reduction after 40 min incubation in gastric fluids versus 5 log 10  CFU reduction in the first 10 min for free cells. The SEM images indicated that the NPs may lead to enhanced probiotic viability by filling pores inside the microgels, which may have inhibited the ability of oxygen and hydrogen ions to access the probiotics. Moreover, the MgO NPs neutralized the hydrogen ions in the gastric fluids, thereby reducing acid-induced degradation of the probiotics. These results demonstrate that MgO-loaded microgels may be a promising encapsulation and delivery system for improving the efficacy of orally administered probiotics by protecting them from the harsh conditions during storage and in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

The present study offers detailed insights into the antifungal and anti-mycotoxigenic potential of a biofilm forming lactic acid bacterium (Pediococcus pentosaceus) against one atoxigenic (Aspergillus flavus) and two toxigenic (Aspergillus nomius and Fusarium verticillioides) fungal strains. The antifungal effect of P. pentosaceus LBM18 strain was initially investigated through comparative analysis of fungi physiology by macroscopic visual evaluations and scanning electron microscopy examinations. The effects over fungal growth rate and asexual sporulation were additionally accessed. Furthermore, analytical evaluations of mycotoxin production were carried out by HPLC-MS/MS to provide insights on the bacterial anti-mycotoxigenic activity over fungal production of the aflatoxins B1, B2, G1 and G2 as well as fumonisins B1 and B2. Finally, reverse transcription quantitative real-time PCR (RT-qPCR) analysis was employed at the most effective bacterial inoculant concentration to evaluate, at the molecular level, the down-regulation of genes aflR , aflQ and aflD , related to the biosynthesis of aflatoxins by the strain of Aspergillus nomius. The effects over mycotoxin contamination were thought to be result of a combination of several biotic and abiotic factors, such as interaction between living beings and physical-chemical aspects of the environment, respectively. Several possible mechanisms of action were addressed along with potentially deleterious effects ascribing from P. pentosaceus misuse as biopesticide, emphasizing the importance of evaluating lactic acid bacteria safety in new applications, concentrations, and exposure scenarios. • Pediococcus pentosaceus presents potentially deleterious effects on mycotoxins • Promising use of Pediococcus pentosaceus as a biopesticide • Antifungal effect of Pediococcus pentosaceus • Morphological changes of atoxigenic and toxigenic fungi by Pediococcus pentosaceus [ABSTRACT FROM AUTHOR]

Six bacterial species were evaluated to determine their inhibitory effects on Clostridium perfringens in vitro (brain heart infusion broth) and in situ (chicken breast meat) under temperature abuse conditions (4 ± 1 °C for 12 h, followed by 7 h at 28 ± 1 °C and then 4 ± 1 °C for 53 h). During abusive storage, rapid growth of C. perfringens from vegetative cell and spore inocula was observed, exhibiting a 2.68–3.37 log CFU/mL (or g) increase in bacterial counts. In the presence of Pediococcus pentosaceus P1 or Lactobacillus fermentum R6, the counts of C. perfringens remained unchanged in the samples containing vegetative cells at the end of storage ( P < 0.05); for those containing spores, the germination and outgrowth were also effectively inhibited, decreasing in bacterial counts of > 1.9 log CFU/mL (or g) compared to those of the control ( P < 0.05). The pH of chicken meat was slightly declined by 0.09 in the presence of L. fermentum ( P > 0.05), and the inhibitory effect against C. perfringens was ascribed to non-acid antimicrobial substances. These results indicate a potential solution for bio-protecting chicken meat from C. perfringens growth. Industrial relevance Clostridium perfringens is a common pathogen that contaminates meat and meat products, but the organism cannot multiply under cold chain conditions at 4 °C. However, it was reported that temperature abuses commonly occurred during the transportation, storage or retail display of the food chill chain. During the abusive storage, C. perfringens could grow rapidly, which may lead to food poisoning. It is a serious problem for food safety. In this study, Lactobacillus fermentum R6 was found to show effective inhibition on both the growth of C. perfringens vegetative cells and the germination and outgrowth of its spores in chicken meat ( P < 0.05) under temperature abuse conditions, and also it had a minimal effect on the pH of the meat ( P > 0.05). The results reveal a potential technology for bio-protecting chicken meat from C. perfringens growth. [ABSTRACT FROM AUTHOR]

Incomplete sugar catabolism occurs in many traditional vegetable-based lactic fermentations, such as sauerkraut and kimchi. The goal of this study was to extend sugar catabolism and improve growth of a mixed lactic starter ( Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococcus acidilactici ) by adding a citrate buffer salt or by external pH control. Fermentation of a vegetable juice medium (VJM) with external pH control (pH =5.6) enabled utilization of 92% of total sugars after 72 h at 20 °C. When 25–100 mM sodium citrate was added to the VJM, a 3.5-fold increase in viable counts of Leuconostoc mesenteroides occurred in fermented VJM and lower levels of residual sugars were obtained in the fermented product. These results suggest that addition of sodium citrate into VJM prior to fermentation could increase sugar catabolism as well as viable counts of lactic bacteria with some being potentially probiotic. [ABSTRACT FROM AUTHOR]

Probiotics have gained increasing attention due to several health benefits related to the human digestive and immune systems. Pediococcus spp. are lactic acid bacteria (LAB) that are widely described as probiotics and characterized as coccus-shaped bacteria (arranged in tetrads), Gram-positive, non-motile, non-spore forming, catalase-negative, and facultative anaerobes. There are many Pediococcus strains that produce pediocin, an effective antilisterial bacteriocin. Pediocins are small, cationic molecules consisting of a conserved hydrophilic N-terminal portion containing the YGNGV motif and an amphiphilic or hydrophobic C-terminal variable portion. A number of studies have been developed with Pediococcus isolated from multiple biological niches to conduct fermentation processes for pediocin or Pediococcus cell production. This review gathers the most significant information about the cultivation, mode of action, and variability of bacteriocins produced by Pediococcus spp., emphasizing their applications in the areas of food and clinical practice. This updated panorama assists in delimiting the challenges that still need to be overcome for pediocin use to be approved for human consumption and the food industry. [ABSTRACT FROM AUTHOR]

We isolated and characterized bacteriocin producers Enterococcus hirae ST57ACC and Pediococcus pentosaceus ST65ACC from raw milk artisanal cheeses. Their bacteriocins were tolerant to temperatures from 4°C to 100°C and under sterilization conditions (121°C for 15 min). Additionally, the tested bacteriocins remained active after being exposed to pH 2.0 to 10.0 for 2 h. The activity of the bacteriocins was affected by proteolytic enzymes but remained stable after treatment with EDTA, sodium dodecyl sulfate, NaCl, skim milk, and Tween 80. Cell-free supernatants were capable of inhibiting Listeria innocua and several strains of Listeria monocytogenes obtained from different sources and belonging to different serotypes. When L. monocytogenes 211 and L. monocytogenes 422 were treated with bacteriocins, growth was completely inhibited over 12 h. Cocultures of bacteriocinogenic strains and L. monocytogenes 422 in skim milk showed that E. hirae ST57ACC could control the growth of the pathogen in the matrix after 48 h. None of the selected isolates presented positive results on a screening panel for 25 bacteriocin-related genes, however, indicating that both strains might express novel bacteriocins. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a common microorganism that causes food spoilage. Pediocins are some biologically active peptides or proteins encoded by ribosomes, which have a strong antimicrobial activity against L. monocytogenes. In this study, the antimicrobial activity of previously isolated P. pentosaceus C-2-1 was enhanced by ultraviolet (UV) mutagenesis. A positive mutant strain P. pentosaceus C23221 was obtained after 8 rounds of UV irradiation with increased antimicrobial activity of 1448 IU/mL, which was 8.47 folds higher than that of wild-type C-2-1. The genome of strain C23221 and wild-type C-2-1 was compared with identify the key genes for higher activity. The genome of the mutant strain C23221 consists of a chromosome of 1,742,268 bp, with 2052 protein-coding genes, 4 rRNA operons, and 47 tRNA genes, which is 79,769 bp less than the original strain. Compared with strain C-2-1, a total of 19 deduced proteins involved in 47 genes are unique to C23221 analyzed by GO database; the specific ped gene related to bacteriocin biosynthesis were detected using antiSMASH in mutant C23221, indicating mutant C23221 produced a new bacteriocin under mutagenesis conditions. This study provides genetic basis for further constituting a rational strategy to genetically engineer wild-type C-2-1 into an overproducer. [ABSTRACT FROM AUTHOR]

A study was conducted examining the effects of prebiotics and probiotics separately and in combination on growth parameters, fecal and cecal microbiota. Six dietary treatments consisted of: 1) control, 2) control + 0.2 lb/ton calculated to contain 1 x 1010 Pediococcus acidilactici/ kg, 3) control + 0.2 lb/ton calculated to contain 2 x 1010 live Saccharomyces cerevisiae boulardii/kg, 4) control+2 lb/ton yeast cell wall extract (YCWE), 5) control+0.2 lb/ton calculated to contain 1 x 1010 /kg Pediococcus acidilactici/kg and + 2 lb/ton YCWE, and 6) control + 0.2 lb/ton calculated to contain 2 x 1010/kg live Saccharomyces cerevisiae boulardii/kg + 2 lb/ton YCWE. Dietary treatments had 10 replicates during the brooder phase; 6 replicates from grower phase through conclusion of the study. Bovan white pullets were utilized for the study. There was not a significant difference between treatments for feed intake, body weight, body weight gain or feed conversion. There were no significant differences between treatments for Salmonella enteritidis presence or fecal counts of E. coli, coliform, and Salmonella spp. Cecal E. coli and coliform counts were not affected by treatment. There was a significant treatment by time effect for Enterobacteriaceae cecal counts. Enterobacteriaceae counts increased at 16 wk of age and decreased through the study for all treatments, except for YCWE. The addition of prebiotics and probiotics, individually or in combination, did not significantly improve growth or alter the potentially pathogenic bacteria microbiology of feces or ceca in pullet chicks. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) synthesize a wide variety of biochemical compounds during food fermentation. Carotenoids provide important biological functions for bacteria, and their consumption by humans has many beneficial effects. In this study, the presence of several genes involved in the production of carotenoids was determined by BLAST analysis and PCR in a collection of 156 LAB isolated from traditional amylaceous African fermented foods. Only the crtE gene and the crtNM operon were present and detected in Lactobacillaceae . Most of the strains with positive PCR detection of the operon crtNM produced carotenoid-like compounds when grown in MRS broth. The carotenoids produced differed from compounds previously identified in other LAB except for one peak, which was closely related to 4,4′-diaponeurosporene already reported in the literature in Lactobacillus plantarum species. Most producing strains belonged to Lactobacillus fermentum and L. plantarum species but a few Pediococcus acidilactici were also producers. Furthermore, the most efficient L. plantarum was able to synthesize carotenoids in a cereal fermented food. Genetic screening was shown to be efficient since, in all cases, it eliminated the need for biochemical analysis of strains in which no amplicons of the operon crtNM were obtained. [ABSTRACT FROM AUTHOR]

The current study was performed to test the ability of the Pediococcus pentosaceus NCDC 273 strain for rapid utilization of lactose from paneer whey. We optimized the lactose utilization by monitoring the constitutive expression of the β-gal gene using real-time RT-PCR and also quantified lactic acid production using high-performance liquid chromatography (HPLC). Screening of β-gal gene for lactose utilization efficiency in P. pentosaceus NCDC 273 strain efficiency showed a significant (P < 0.0001) expression of the β-gal gene in the supplemented paneer whey medium (SPWM; lactose rich) compared to commercially available Deman-Rogosa-Sharpe (MRS; d -glucose rich) broth medium. In addition, with the growth of P. pentosaceus NCDC 273 in SPWM, the expression of the β-gal gene was found significantly (P < 0.001) higher at 6h of fermentation during the exponential growth phase and declining no significantly at stationary phase. After 48 h of incubation, HPLC data revealed a high lactose conversion rate (42.12%) to lactic acid production (14.50 ± 0.48 g L−1). Moreover, pediocin PA-1 activity in fermented SPWM showed almost contamination-free lactic acid production. Hence, our results showed the sustainable utilization of dairy waste paneer whey for lactic acid production by P. pentosaceus NCDC 273 at a lower disposal cost. [Display omitted] • Potential of Pediococcus pentosaceus NCDC 273 for the sustainable utilization of dairy waste paneer whey. • Highest lactose conversion (42.12%) was observed to produce lactic acid (14.50 ± 0.48 g L−1) after an incubation period of 48 h. • Pediocin PA-1 activity showed almost contamination free lactic acid production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metabolomics analysis of sausage's volatile and non-volatile metabolites. • Characteristic flavor substances after fermentation were ascertained. • Uncovering the pathways regulated by P. pentosaceus and S. carnosus. • Characteristic flavor substances and non-volatile metabolites were correlated. A multi-omics approach was applied to investigate the differences and correlations between characteristic volatile flavor substances and non-volatile metabolites in sausages fermented by Pediococcus pentosaceus (P. pentosaceus) and Staphylococcus carnosus (S. carnosus) alone and in a mixture. Twenty-seven volatile metabolites were identified by headspace solid-phase microextraction/gas chromatography-mass. According to orthogonal projections to latent structures–differential analysis, 17 characteristic volatile metabolites were detected in the sausages of different treatments. Utilizing ultra-high-performance liquid chromatography coupled with a mass spectrometer to analyze metabolite profiles, 42.03% of the non-volatile metabolites were classified as lipids and lipid-like molecules, 25.00% of organic acids and derivatives, and others. Seventeen characteristic flavor substances were significantly correlated with twenty differential non-volatile metabolites, and the non-volatile metabolites changed significantly. Differences in the characteristics and combinations of microorganisms themselves have a decisive role in the development of flavor substances and non-volatile metabolites in sausages. [ABSTRACT FROM AUTHOR]

In Alzheimer's disease (AD), the amyloid-β (Aβ) protein begins to accumulate in the brain 20 years prior to any dementia symptoms manifestation, in which Aβ aggregates in the brain, causing destruction of nerve cells and resulting in memory impairments. Lifestyle and diet appear to inhibit Aβ production and amyloid deposition. Therefore, identifying factors that prevent Aβ production and administering them before the onset of AD, may be an effective preventive method. Lactic acid bacteria (LAB) exhibit various health effects on the host and are expected to have protective effects on neurological functions via brain-gut correlation. However, the protective effects of LAB against Aβ are not well understood. We investigated whether LAB feeding could ameliorate the toxicity of Aβ peptide accumulation in transgenic Caenorhabditis elegans expressing the human Aβ peptide in neurons or muscle as an AD model. Aβ expressed in muscle caused myopathy and worm paralysis, while Aβ in neurons disturbed chemotactic activity. Among 14 screened strains, Lactococcus laudensis (LL) and Pediococcus parvulus (PP) prevented the AD worms from losing their chemotaxis behavior and becoming paralyzed by the Aβ peptide. Immunostaining and western blotting indicated that Aβ peptide was significantly suppressed in worms fed these two strains, and binding of the Aβ to vitellogenin was particularly inhibited. Conversely, the mRNA level of the Aβ gene did not change between LL- or PP-fed worms and the control. In conclusion, LL and PP alleviate neurotoxicity by inhibiting Aβ accumulation; AD model worms can be used to screen efficient LAB for AD prevention. [Display omitted] • Lactic acid bacteria maintained chemotaxis of transgenic worms expressing Aβ 1–42. • L. laudensis and P. parvulus improved myopathy induced by the expression of Aβ 1–42. • L. laudensis and P. parvulus reduced the accumulation of Aβ 1–42 peptide in worms. [ABSTRACT FROM AUTHOR]

3-Phenyllactic acid (PLA) is a broad-spectrum antimicrobial compound, produced by a wide range of lactic acid bacteria. A novel lactic acid bacteria strain with high PLA-producing ability, Pediococcus pentosaceus SK25, was isolated from traditional Chinese pickles. When grown in de Man, Rogosa, Sharpe broth at 30°C for 36 h, this strain produced 135.6 mg/L of PLA. Using this strain as starter for milk fermentation, 47.2 mg/L of PLA was produced after fermentation for 12 h. The PLA production was significantly improved by phenylalanine supplement, but was completely inhibited by tyrosine supplement. [ABSTRACT FROM AUTHOR]

Production of pediocin SM-1 by Pediococcus pentosaceus Mees 1934 was investigated in semi-aerobic, pH-controlled, batch and fed-batch fermentations using a complex medium containing sucrose as the main source of carbon. The effects of sucrose concentration were studied in fed-batch fermentations in which a sucrose solution was added at stable feeding rates (5, 7, 9 and 10 g/l/h). The results showed that pediocin is produced as a product of the primary metabolism and its titer could be greatly improved by adjusting the sucrose feeding rate in fed-batch fermentation. The maximum titer of pediocin of 145 AU/ml was obtained in the fed-batch culture with 7 g/l/h feeding rate and that was 119% higher compared to the titer obtained in batch culture. Higher feeding rates (9 and 10 g/l/h) resulted in decreased pediocin yields while biomass levels appeared to be rather unaffected. The specific rate of pediocin formation was also sensitive to sucrose concentration levels. A mathematical model developed on the basis of well-known rate equations for batch and fed-batch cultures and growth associated production, described successfully cell growth, sucrose assimilation, lactate production and pediocin production in fed-batch culture. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) are a promising solution to reduce exposure to dietary mycotoxins because of the unique mycotoxin decontaminating characteristic of some LAB. Ochratoxin A (OTA) is one of the most prominent mycotoxins found in agricultural commodities. The present work reports on the ability of Pediococcus parvulus strains that were isolated from Douro wines that spontaneously underwent malolactic fermentation to detoxify OTA. These strains were identified and characterised using a polyphasic approach that employed both phenotypic and genotypic methods. When cultivated on OTA-supplemented MRS media, OTA was biodegraded into OTα by certain P. parvulus strains. The presence of OTα was confirmed using LC-MS/MS. The conversion of OTA into OTα indicates that the OTA amide bond was hydrolysed by a putative peptidase. The rate of OTA biodegradation was found to be dependent on the inoculum size and on the incubation temperature. Adsorption assays with dead P. parvulus cells showed that approximately 1.3% ± 1.0 of the OTA was adsorbed onto cells wall, which excludes this mechanism in the elimination of OTA by strains that degrades OTA. Under optimum conditions, 50% and 90% of OTA were degraded in 6 and 19 h, respectively. Other LAB strains that belonged to different species were tested but did not degrade OTA. OTA biodegradation by P. parvulus UTAD 473 was observed in grape must. Because some P. parvulus strains have relevant probiotic properties, the strains that were identified could be particularly relevant to food and feed applications to counteract the toxic effects of OTA. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to isolate and identify anti-listerial substances produced by lactic acid bacteria in Kimchi, a traditional fermented vegetable. The Pediococcus pentosaceus T1 strain, which has an antimicrobial effect on Listeria monocytogenes, was isolated from Kimchi using 16S rRNA analysis. A crude culture of P. pentosaceus T1 demonstrated anti-listerial activity that was unaltered by pH changes in the range of 4–8 and temperatures between 80 and 110 °C. However, anti-listerial activity of P. pentosaceus T1 was abolished upon protease- and lipase-treatments, suggesting that the active substances were composed of peptides and lipids. Amylase, however, showed very little change in activity when compared to the control. Passage of the culture supernatant over Sep-Pak C18 cartridges showed that the anti-listerial activity could be traced to a component in the water-soluble fraction. Further purification of the activity was carried out using a series of steps that included ammonium sulfate precipitation, desalting, ion exchange chromatography, and ultrafiltration of the supernatants of P. pentosaceus cultures. The active fraction showed the presence of a 23-kDa protein, as visualized by SDS-PAGE followed by coomassie blue staining. Liquid chromatography (LC) and mass spectrometry (MS) analyses of the protein confirmed the presence of a Lysin motif (LysM) domain, which is known to be present in bacterial peptidoglycan hydrolases. In this study, we have demonstrated that Kimchi-derived P. pentosaceus shows an anti-listerial activity, and identified the active moiety as a LysM domain in a 23-kDa protein. [Copyright &y& Elsevier]

[Display omitted] • Absolute microbiota abundances in Daqu were investigated using spike-in methods. • Differences in microbiotas and metabolites of Daqu depending on the temperature. • Genomoviridae , Mimiviridae , and Siphoviridae were dominant phages in Daqu. Daqu has a rich and diverse microbiota, giving them a suitable biotope for phages. However, the absolute abundances of bacteria and fungi, as well as the phage community characteristics in Daqu , remain unclear. In this study, the microbiota absolute abundance, indigenous phage composition and function, and volatile compound profiles of high-temperature Daqu (HTDQ), medium-temperature Daqu (MTDQ), and low-temperature Daqu (LTDQ) were investigated. Absolute microbiota quantification revealed that there were significant variations in microbial composition and absolute abundance across three types of Daqu. The absolute abundances of the top 30 bacterial genera in LTDQ, MTDQ, and HTDQ were 6.0 × 105, 5.3 × 104, 1.4 × 105 copies/ng DNA, while the top 30 fungal genera had 8.5 × 107, 2.1 × 106, and 6.2 × 105 copies/ng DNA, respectively. LTDQ were enriched in Pantoea , Staphylococcus , and Saccharomycopsis ; MTDQ were dominated by Saccharopolyspora , Staphylococcus , Saccharomycopsis , and Aspergillus ; HTDQ were dominated by Saccharopolyspora , Bacillus , Byssochlamys , and Saccharomycopsis. Volatile profile analysis revealed that LTDQ, MTDQ, and HTDQ comprised 68, 68, and 75 compounds, respectively, with 39 compounds shared by the three types. Fourteen volatile compounds were identified as highly discriminative features among three types of Daqu , which were closely related to Saccharopolyspora , Thermoactinomyces , Kroppenstedtia , Byssochlamys , and Thermomyces. Metaviromics indicated that Genomoviridae , Mimiviridae and Siphoviridae , and Parvoviridae were the dominant viruses in LTDQ, MTDQ, and HTDQ, respectively. The hosts of phages in Daqu mainly included Lactobacillus , Enterobacter , Pantoea , Bacillus , Pediococcus , and Staphylococcus. Phages may prey on numerous microbes living on Daqu via pathways such as genetic information processing, signaling and cellular processes, and replication and repair. This study highlights the use of absolute quantification to avoid misjudgment of differential taxa in comparative microbiome analysis and provides new insights into the phage community and function in Daqu. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sarcoplasmic and myofibrillar proteins were degraded in both preparations. [•] Increases of α-amino nitrogen and free amino acids are related to inoculated strain. [•] More intense proteolysis was found in sausages with Pediococcus pentosaceus GY23. [•] The content increases in TCA-soluble peptides were similar in both sausages. [ABSTRACT FROM AUTHOR]

The gene encoding l-arabinose isomerase from food-grade strain Pediococcus pentosaceus PC-5 was cloned and overexpressed in Escherichia coli. The recombinant protein was purified and characterized. It was optimally active at 50°C and pH 6.0. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its maximal activity evaluated at 0.6mM Mn2+ or 0.8mM Co2+. Interestingly, this enzyme was distinguished from other l-AIs, it could not use l-arabinose as its substrate. In addition, a three-dimensional structure of l-AI was built by homology modeling and l-arabinose and d-galactose were docked into the active site pocket of PPAI model to explain the interaction between l-AI and its substrate. The purified P. pentosaceus PC-5 l-AI converted d-galactose into d-tagatose with a high conversion rate of 52% after 24h at 50°C, suggesting its excellent potential in d-tagatose production. [ABSTRACT FROM AUTHOR]

Abstract: The porous branched dextran of molecular mass 2.93×105 Da with 50% overall yield (4.5mg/ml) was produced from Pediococcus pentosaceus CRAG3 (GenBank ID: JX679020), a novel isolate from fermented cucumber. It contained glucose monomers linked through 75% α-(1,6) linkage with 25% (α-1,3) branching as displayed by spectroscopic analysis. The peak analysis showed α-(1,3) branching after every five glucose units of main chain. In vitro cytotoxicity analysis of dextran displayed anti-cancer activity against cervical cancer (HeLa) and colon cancer (HT29) cell lines opening new horizons in its pharmaceutical applications. Dextran showed enhanced growth of macrophage lines revealing its biocompatible nature. [Copyright &y& Elsevier]

Abstract: The aim was to produce Nham that was enriched with γ-aminobutyric acid (GABA); therefore two GABA producing lactic acid bacteria (Pediococcus pentosaceus HN8 and Lactobacillus namurensis NH2) were used as starter cultures. By using the central composite design (CCD) we showed that addition of 0.5% monosodium glutamate (MSG) together with an inoculum size of roughly 6logCFU/g of each of the two strains produced a maximal amounts of GABA (4051mg/kg) in the ‘GABA Nham’ product. This was higher than any current popular commercial Nham product by roughly 8 times. ‘GABA Nham’ with the additions of both starters and MSG (TSM) supported maximum populations of lactic acid bacteria (LAB) with a minimum of yeasts and no staphylococci or molds when compared to the controls that had no addition of any starters or MSG (TNN), or only the addition of MSG (TNM), or with only the starter (TSN). Based on proximate analysis among the Nham sets, ‘GABA Nham’ was low in fat, carbohydrate and energy although its texture and color were slightly different from the control (TNN). However, sensory evaluations of ‘GABA Nham’ were more acceptable than the controls and commercial Nham products for all tested parameters. Hence, a unique novel ‘GABA Nham’ fermented pork sausage was successfully developed. [Copyright &y& Elsevier]

The goal of this study was to examine the esterase activity of 243 lactic acid bacteria (LAB) strains from wines of different red grape varieties, belonging to the genera Oenococcus, Lactobacillus, Pediococcus and Enterococcus. p-Nitrophenyl octanoate was used as substrate. All strains presented esterase activity in the first screening, but only those showing higher activity were used in subsequent studies to determine the cellular location of this activity, the influence of pH, temperature and the presence of ethanol and the substrate specificity. For the thirteen selected strains, the highest activity was observed in the intracellular fraction. Responses to pH, temperature and ethanol were strain-dependent, but for all the strains, a marked decrease in activity in presence of ethanol was observed. When the influence of pH and ethanol acting together was studied at 25°C and 37°C, temperature-dependent differences were not observed for any of the strains except for Oen6. In the substrate specificity assay, the majority of strains of all genera displayed a trend to more readily hydrolyse ester substrates from C8 and longer. [ABSTRACT FROM AUTHOR]

Abstract: An original method combining two conductometric biosensors is proposed for the determination of total lactate, l- and d-lactate in dairy products. The biosensors were prepared through cross-linking of l-lactate oxidase from Pediococcus sp. (LODP) or a combination of LODP and horseradish peroxidase (HRP) at the surface of gold interdigitated microelectrodes using glutaraldehyde (GA) vapors. LODP is reported to catalyze specifically l-lactate oxidation into pyruvate and hydrogen peroxide in solution. In this work, we showed that LODP chiral selectivity was lost following enzyme cross-linking, rendering LODP sensor suitable for total lactate determination. Biosensor sensitivity towards both stereoisomers was 1.16±0.04μSμM−1. The addition of HRP significantly improved the linear range and stability of LODP biosensor, but also increased its sensitivity, the effect being more pronounced for d-lactate (+381%) than for l-lactate (+260%). This result was attributed to a modification in LODP chiral selectivity combined with the production of additional ions (acetate, H+ and HCO3 −) via the HRP-catalyzed oxidation of pyruvate. A method, taking advantage of the difference in d- and l-lactate behaviours and combining the monoenzymatic and bienzymatic biosensors calibration data, was proposed for the calculation of their concentrations in unknown samples. Different parameters (HRP/LODP ratio, exposure time to GA vapors, pH and concentration of measurement medium) were optimized in order to achieve the best compromise between sensitivity and stability of the biosensors. The best limit of detection for l- and d-lactate, calculated as three times the signal to noise ratio was achieved with the bi-enzymatic sensor and was equal to 0.05μM. LODP/HRP biosensor response towards l-lactate was not significantly affected by glucose, fructose and lactose. The proposed biosensors were finally applied to the determination of total lactate, d- and l-lactate concentrations in yogurt samples. Results were in good agreement with those obtained using a reference colorimetric enzymatic method. [Copyright &y& Elsevier]