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BACKGROUND: Microbiota succession determines the flavor and quality of fermented foods. Quantitative PCR‐based quantitative microbiome profiling (QMP) has been applied broadly for microbial analysis from absolute abundance perspectives, transforming microbiota ratios into counts by normalizing 16S ribosomal RNA (16S rRNA) gene sequencing data with gene copies quantified by quantitative PCR. However, the application of QMP in fermented foods is still limited. RESULTS: QMP elucidated microbial succession of Taiwanese pickled cabbage. In the spontaneous first‐round fermentation (FR), the 16S rRNA gene copies of total bacteria increased from 6.1 to 10 log copies mL−1. The dominant lactic acid bacteria genera were successively Lactococcus, Leuconostoc and Lactiplantibacillus. Despite the decrease in the proportion of Lactococcus during the succession, the absolute abundance of Lactococcus still increased. In the backslopping second‐round fermentation (SR), the total bacteria 16S rRNA gene copies increased from 7.6 to 9.9 log copies mL−1. The addition of backslopping starter and vinegar rapidly led to a homogenous microbial community dominated by Lactiplantibacillus. The proportion of Lactiplantibacillus remained consistently around 90% during SR, whereas its absolute abundance exhibited a continuous increase. In SR without vinegar, Leuconostoc consistently dominated the fermentation. CONCLUSION: The present study highlights that compositional analysis would misinterpret microbial dynamics, whereas QMP reflected the real succession profiles and unveiled the essential role of vinegar in promoting Lactiplantibacillus dominance in backslopping fermentation of Taiwanese pickled cabbage. Quantitative microbiome profiling (QMP) was found to be a more promising approach for the detailed observation of microbiome succession in food fermentation compared to compositional analysis. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Summary: This study aimed to comprehend the spoilage of cooked turkey ham caused by various Leuconostoc species using multivariate analysis to link the growth of these microorganisms, pH kinetics, and mesophilic counts for predicting ham spoilage at 8 and 12 °C. The methodology assesses changes in Leuconostoc spp. growth behaviour using the Baranyi and Roberts model, pH kinetics employing the Weibull model, and milkiness and swelling through quantitative descriptive analysis during storage at 8 and 12 °C, with artificial contamination of Leuconostoc carnosum and L. mesenteroides at 102 and 104 CFU g−1. Multivariate analysis encompasses linear quadratic discriminant and Pearson correlation analysis. Biokinetic growth parameters do not significantly differ among Leuconostoc species, temperatures, or inoculum levels. In discriminant analysis, pH is the most influential variable in spoilage grade classification, followed by LAB log counts. Furthermore, correlation analysis reveals a strong positive correlation between the rate of pH reduction and the storage time for spoilage onset. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was undertaken in order to explore the correlation between the quality changes and microbial community in sauced duck necks during cold storage. Commercial sauced duck necks in modified atmosphere packaging were stored at 4 °C for 1, 4, 7, 10, and 13 days, and the changes in pH, thiobarbituric acid reactive substances (TBARS) value, color, texture, total bacterial count, total volatile base nitrogen (TVB-N) content, and microbial community were analyzed. The results showed that the pH initially decreased and then increased with storage time, while brightness (L*), redness (a*), yellowness (b*) and hardness exhibited a decreasing trend, and elasticity, chewiness, cohesiveness and adhesiveness showed an initial increase followed by a decrease. The total bacterial count, TVB-N and TBARS values all gradually increased during storage, with the total bacterial count and TVB-N exceeding the acceptable limits on the 10th day. Microbial diversity diminished gradually with storage time. At the initial stage of storage, the dominant bacteria were Rhodococcus, Acinetobacter, Ureibacillus and Symbiobacterium, while those in the late storage period were Rhodococcus, Acinetobacter, Leuconostoc and Lactobacillus. Principal co-ordinate analysis indicated the two principal coordinates explained 74.03% of the variation, and differences in microbial community composition occurred after 4 days of storage. Correlation analysis showed that Leuconostoc was positively correlated with pH, total bacterial count, TVB-N content and TBARS value during cold storage of sauced duck necks, indicating that Leuconostoc was the primary spoilage bacteria during storage. [ABSTRACT FROM AUTHOR]

The demand for meat alternatives in different forms is increasing due to consumers' awareness of climate change and the health benefits of plant-based ingredients compared to animals. However, current alternatives on the market do not fulfil consumers' acceptance for taste and texture. Hence, different physical and biological processes, such as thermal treatment and fermentation, need to be investigated. This study reveals that the thermal treatment of legume flours (soy, pea and lentil) prior to single-strain fermentation with Leuconostoc citreum TR116 has a major impact on acidification, colour, texture and sensory properties due to the pregelatinisation of starch and denaturation of proteins. The thermal treatment of soy flour resulted in liquification, and it could not be used as a fermentation substrate. However, non-heat-treated soy flour was fermented for comparison. The highest total titratable acidity (TTA) was determined in fermented pea flour (PF) and fermented lentil flour (LF) after 48 h with 24.35 ± 0.29 mL 0.1 M NaOH/10 g and 24.98 ± 0.33 mL 0.1 M NaOH/10 g, respectively. Heat treatment prior to fermentation led to a reduction in TTA by 20 mL 0.1 M NaOH/10 g for both PF and LF. The loss of colour pigments during thermal treatment led to a lighter colour of the spreadable alternatives. Moreover, a harder texture (+13.76 N in LF; +15.13 N in PF) and a lower adhesiveness (−0.88 N in LF; −0.43 N in PF) were detected in spreadable meat alternatives that were treated with heat prior to fermentation. Cohesiveness was decreased by thermal treatment, and fermentation did not impact it. Fermentation without pre-heat treatment increased adhesiveness by 4.37 N in LF and by 2.36 N in PF—an attribute typical for spreadable meat. Descriptive sensory analysis showed that thermal treatment significantly decreased bitterness but increased crumbliness and reduced juiciness. On the other hand, fermentation without pre-heat treatment mainly influenced flavour by increasing fruitiness and decreasing beaniness, earthiness and off-flavours. In summary, thermal treatment prior to fermentation is powerful in reducing legume-typical off-flavours but is not suitable for the development of spreadable meat alternatives due to texture changes. However, this process can be very beneficial when producing sausage-like alternatives. [ABSTRACT FROM AUTHOR]

Introduction: : Lactic acid bacteria (LAB) are a cluster of microbes distributed in a variety of environments and have potential probiotic activity to improve human well-being. This study was aimed at assessing the probiotic potential of LAB isolated from Cheka, an Ethiopian traditionally fermented beverage. Method: Pure isolates obtained from 16 Cheka samples from Konso (n = 8) and Derashe (n = 8) were characterized morphologically, biochemically, and physiologically by considering basic criteria to identify the LAB. The probiotics properties of the LAB were evaluated in vitro at low pH values (2.0 and 3.0), and two bile salt concentrations (0.3 and 0.5%) for 3 and 6 h. The 16 S rRNA gene sequencing was done using an ABI 3730xl sequencer, and the gene sequences were aligned. Results: Of the 27 pure isolates, 11 isolates were proven to be LAB with non-motile, negative for catalase, and non-spore former characteristics. Based on cultural characteristics and sugar fermentation ability, the 11 isolates were assembled into the genera Lactobacillus (55%), Lactococcus (18%), Pediococcus (18%), and Leuconostoc (9%). At pH 3.0 and a bile salt concentration of 0.3%, isolate ChK-11 showed a better survival rate (97 and 94%) than other isolates [ChK-7 (93 and 80%) > ChD-5 (84 and 76%) > ChD-8 (46 and 36%) > ChK-4 (41 and 34%)] for 6 and 3 h, respectively. According to 16 S rRNA sequencing results, isolates ChK-11 and ChK-7 were found to be Weissella paramesenteroides and Leuconostoc pseudomesenteroides with sequence similarity of 99 and 91%, respectively. Conclusions: In the present study, probiotic LAB (Weissella paramesenteroides and Leuconostoc pseudomesenteroides) was successfully isolated and sequenced from Cheka samples. The findings of this in vitro study indicated that fermented beverages like Cheka are a source of the LAB with probiotic functional properties. Overall, Weissella paramesenteroides and Leuconostoc pseudomesenteroides isolates, which showed promising probiotic properties under in vitro conditions, can be used for starter culture development for the Cheka fermentation process. [ABSTRACT FROM AUTHOR]

Leuconostoc encompasses a number of species that frequently appear in foods where they play different roles, ranging from ripening to spoiling. The number of available Leuconostoc genomes has recently increased and enabled the precise taxonomic and phylogenetic delineation of species. Nonetheless, a thorough investigation of the functions and the metabolic potential of Leuconostoc species has never been accomplished. In this study, all the currently available 553 Leuconostoc genomes were downloaded from NCBI GenBank and annotated utilizing specific tools in order to reconstruct the metabolic potential of the genus in terms of carbohydrate hydrolysis and fermentative pathways, transporters, and anabolic potential. The analysis revealed that species cluster based on their metabolic potential, showing unique adaptation and ecological roles. Pentose phosphate and phosphoketolase pathways were highlighted as the main ones of central metabolism. The various identified PTS and ABC transporters showed adaptability to different sugars. The metabolic diversity described in this study not only supports the role of Leuconostoc spp. in natural ecosystems but also highlights their potential in industrial applications, particularly in the fermentation industry where their ability to metabolize a wide range of substrates can be harnessed for the production of various fermented foods and bioproducts. [ABSTRACT FROM AUTHOR]

Kishk is a traditional dry fermented dairy product prepared from a mixture of salted sour butter milk or yoghurt with wheat grains. The goal of this study was to evaluate the microbiological quality, together with isolation and identification of LAB from kishk and assessed their protective effects against E. coli and Pseudomonas aeruginosa in vitro and in vivo. One hundred samples of kishk were randomly obtained from farmers' houses and food stores in the Assiut governorate, Egypt. Total viable count and, total yeasts and molds were performed by plating the samples on selective media. Further, LAB were isolated on de Man Rogosa and Sharpe (MRS) agar and identified by biochemical tests. The antagonistic effect of the obtained LAB was evaluated against two of foodborne pathogens (E. coli and Pseudomonas aeruginosa) in vitro using well diffusion method and in vivo after inoculation in cow's milk. The average total bacterial and yeasts and molds counts were 8.13±0.09 and 2.92±0.16 log10 CFU/g, respectively. Based on phenotypical examination, LAB were identified and classified into three groups namely Lactobacillus, Leuconostoc and Lactococcus. Notably, LAB had more inhibitory activity against E. coli in comparison to Pseudomonas aeruginosa in vitro. However, there was no changes in the mean count of the tested organisms versus control group after inoculation in milk. This study revealed that kishk contain LAB bacteria that have antagonistic properties on E. coli and Pseudomonas aeruginosa. Hence, kishk could be a useful candidate for human health. [ABSTRACT FROM AUTHOR]

Asymmetric bioreductions have the potential to synthesize chiral alcohols when catalyzed by biocatalysts. Nevertheless, the (S)-phenyl (pyridin-2-yl)methanol ((S)-2) analgesic synthesis poses significant challenges concerning unsatisfactory substrate amount and production method. Thus, this study proposes an inscribed design-focused multi-response nonlinear optimization model for the asymmetric reduction of the phenyl(pyridin-2-yl)methanone (1) with Leuconostoc pseudomesenteroides N13 biocatalyst. From the novel inscribed design-focused multi-response nonlinear optimization model, optimization conditions of the reaction, such as pH = 6, temperature = 29 °C, incubation time = 53 h, and agitation speed = 153 rpm, were found. Also, the reaction conversion was predicted to be 99%, and the product of the enantiomeric excess (ee) was 98.4% under the obtained optimization conditions. (S)-2 was obtained with 99% ee, 99% conversion, and 98% yield while performing a validation experiment using the determined optimized conditions. In addition, 1 with the amount of 11.9 g was converted entirely to (S)-2 (11.79 g, 98% isolated yield) on a high gram scale. Also, this study is noted as the first example of the gram-scale production of (S)-2 using an optimization strategy and biocatalyst. Further, the applicability of the inscribed design-focused optimization model in biocatalytic reactions has been demonstrated and provides an effective process for the analgesic synthesis of (S)-2, which is a green, cost-effective method of producing chiral aryl heteroaryl methanol. [ABSTRACT FROM AUTHOR]

Isolation and identification of acid-producing bacteria from environmental samples is still one of important and effective approaches to obtain strains producing lactic acid with high optical purity. In this study, an isolate strain named HL64-1, producing D-lactic acid with high optical purity, was isolated from rotten fruit. And HL64-1 was characterized as Leuconostoc pseudomesenteroides based on morphology, 16S rDNA sequence analysis and sequence similarity Blast analysis. After fermentation for 24 h, 62.18 g/L D-lactic acid was produced with an optical purity of 99.90%(ee) in basic fermentation culture. The acid production rate was 2.59 g/(L⋅h). Scale-up fermentation of L. pseudomesenteroides HL64-1 in 5-L fermenter for 72 h produced 78.74 g/L D-lactic acid by replenishment of carbon sources, and the average acid production rate was 1.09 g/(L⋅h). Moreover, L. pseudomesenteroides HL64-1 was found to be capable of using effectively cheap raw materials, such as agricultural by-products peanut cake meal and cottonseed meal, as alternative nitrogen sources, leading a reduction of fermentation cost. In addition, L. pseudomesenteroides HL64-1 could metabolize xylose into D-lactic acid. Co-fermentation of glucose and xylose mixtures showed that glucose significantly enhanced the utilization efficiency of xylose, making L. pseudomesenteroides HL64-1 to be a promising strain for pure D-lactic acid industrial production. [ABSTRACT FROM AUTHOR]

In order to study the effects of different lactic acid bacteria on the quality of pickled radish, pickled radish was prepared with Leuconostoc mesenteroides AP7, Lactiplantibacillus pentosus LP10 and AP7-LP10 combination. The changes in physicochemical indicators, color differences, texture properties and sensory indicators during the fermentation process were analyzed. The results showed that the decrease rate of pH and reducing sugar content and the increase rate of total acid and lactic acid in the inoculated group were better than those in the natural fermentation group (P<0.05). For the inoculated group, the nitrite content was low, and no nitrite peak appeared. The pectinase activity remained at a low level. For the AP7-LP10 and AP7 groups, the L* was higher than that of the other two groups (P<0.05), and the browning index and polyphenol oxidase activity remained at a low level. After 7 days of fermentation, the hardness of AP7-LP10 group (70.92±3.94 N) was higher than that of other groups (P<0.05). The sensory score of AP7-LP10 was the highest (92±2.11). In summary, the pickled radish inoculated with lactic acid bacteria is fast to mature and safe. The combination of AP7-LP10 can improve the quality of pickled radish. [ABSTRACT FROM AUTHOR]

In order to improve the safety and preservability of fermented vegetables, strain Leuconostoc mesenteroides AP7, with potent inhibitory effects on foodborne pathogens and bacteria causing paocai over-acidification, was selected from 8 Leuconostoc strains derived from traditional fermented vegetables in Yunnan, China. The main antimicrobial substance of AP7 was determined by eliminating the effects of organic acid and H2O2 and through protease sensitivity. The acid stability and thermal stability were analyzed and potential bacteriocin gene clusters were mined from the whole genome sequence of AP7. The results showed that the culture supernatant still had obvious antibacterial activity after excluding the influence of acid and H2O2, and after protease treatment, the antibacterial effect decreased significantly. It was speculated that the antibacterial substance in the concentrated culture supernatant was bacteriocin. The bacteriocin was sensitive to pH changes, had high thermal stability, and had a molecular weight of 6.51~14.4 kDa. Whole genome sequencing showed that the whole genome of AP7 contained 1 chromosome (1948310 bp) and 2 plasmids (37366 and 20698 bp), with a GC content of 37.7%. There was a gene cluster with Enterocin_X_chain_beta bacteriocin as the core. Its encoded product was predicted to be a positively charged hydrophilic stable protein, the secondary structure was dominated by a-helix, and the tertiary structure was mainly composed of loose peptide chains at both ends and an α-helix in the middle. In summary, the bacteriocin-producing Leuconostoc mesenteroides AP7 has excellent antibacterial properties and has the potential to be applied to the fermentation and preservation of acidic foods. [ABSTRACT FROM AUTHOR]

Cooked sausages packaged in a modified atmosphere (MAP: 20% CO2, 70% N2, <0.2% O2) with evident yellow stains were analyzed. The aims of this work were to study the microbial cause of the spoilage and to evaluate different antimicrobial compounds to prevent it. Leuconostoc gelidum was identified as the primary cause of the yellow coating in spoiled cooked sausage, as confirmed by its intentional inoculation on slices of unspoiled sausage. Leuconostoc gelidum was the main bacteria responsible for the yellow coating in spoiled cooked sausage, as confirmed by its intentional inoculation on slices of unspoiled sausage. The yellow color was also evident during growth in the model system containing cooked sausage extract, but the colonies on MRS agar appeared white, demonstrating that the food substrate stimulated the production of the yellow pigment. The spoilage was also characterized by different volatile compounds, including ketones, ethanol, acetic acid, and ethyl acetate, found in the spoiled cooked sausage packages. These compounds explained the activity of Leuc. gelidum because they are typical of heterofermentative LAB, cultivated either on food substrates or in artificial broths. Leuc. gelidum also produced slight swelling in the spoiled packages. The efficacy of different antimicrobials was assessed in model systems composed of cooked sausage extract with the antimicrobials added at food product concentrations. The data showed that sodium lactate, sodium acetate, and a combination of sodium lactate and sodium diacetate could only slow the growth of the spoiler—they could not stop it from occurring. Conversely, hop extract inhibited Leuc. gelidum, showing a minimal inhibitory concentration (MIC) of approximately 0.008 mg CAE/mL in synthetic broth and 4 mg CAE/kg in cooked sausage slices. Adding hop extract at the MIC did not allow Leuc. gelidum growth and did not change the sensorial characteristics of the cooked sausages. To our knowledge, this is the first report of the antimicrobial activities of hop extracts against Leuc. gelidum either in vitro or in vivo. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from Minas artisanal cheese produced in Campo das Vertentes, MG, and to select bacteria for the production of fermented milk. The following strains, including Lactiplantibacillus plantarum (LPL), Levilactobacillus brevis (LB), Latilactobacillus curvatus (LC), Laticaseibacillus paracasei (LPR), Lactococcus garvieae (LG), Lactococcus lactis (LL), Leuconostoc mesenteroides (LM001), and Leuconostoc pseudomesenteroides (LPS), were assessed for their tolerance to artificial gastric acid and bile salts, susceptibility to antimicrobials, and antagonistic properties. Leuc. mesenteroides (LM001) survived the simulation of gastrointestinal barriers, displayed susceptibility to ten of the 12 antimicrobials tested, and exhibited the ability to inhibit pathogenic microorganisms. Consequently, it was selected for production of fermented milk, which was submitted to physicochemical and microbiological analyses for up to 14 days of storage, yielding results in accordance with current Brazilian legislation. It is recommended that in vivo tests be conducted to assess the probiotic characteristics of Leuc. mesenteroides LM001 for its use in functional foods. [ABSTRACT FROM AUTHOR]

This study combined applied PICRUSt2 and BugBase tools to evaluate the effects of these two strains on the fermentation characteristics, microbial community, potential microbial risk and hygienic quality of whole-crop corn (WCC) silage. Fresh WCC harvested at the dough stage was ensiled with distilled water (CON), Leuconostoc lactis (LS) and Weissella confusa (WA) for 2, 4, 8, 15 and 30 days. After ensiling, all WCC silages presented desirable fermentation with high lactic acid and Lactobacillus proportions, low pH and ammonia nitrogen levels and absent butyric acid. Ensiling decreased the complexity of bacterial co-occurrence networks, and the Lc. lactis and W. confusa inoculation further decreased the complexity. The inoculation of W. confusa suppressed the most pathogenic pathways and related modules associated with zoonosis. In bacterial phenotype predicted analysis, although CON had lower proportions of 'Potentially pathogenic' than fresh material, this undesirable phenotype declined to negligible levels via LS and WA inoculation. Even for well-fermented WCC silages, the risk of pathogens remained after 30 days of ensiling. Therefore, WA could be developed as a promising fast start-up inoculant for reducing pathogenic contamination and improving hygienic quality of silage. [ABSTRACT FROM AUTHOR]

Kimoto -style seed mash making processes such as the kimoto and yamahai - moto processes are driven by various microorganisms, and it is very important to make lactic acid bacteria grow stably for the brewing of a sake product with consistent quality. A model of bacterial transition from spherical lactic acid bacteria to rod-shaped lactic acid bacteria during kimoto -making has been advocated, but the model cannot explain all cases of a transition of a bacterial community during kimoto -making at various breweries. Several studies have described unique bacterial transition patterns that differ from those considered in the proposed model, and it is possible that factors such as differences in the initial bacterial community among breweries may cause the diversity of bacterial transitions. In this minireview, I summarize the research concerning the community of lactic acid bacteria during the kimoto -style seed mash making process, and I discuss how stable lactic acid fermentation can be achieved. [ABSTRACT FROM AUTHOR]

From traditional Gifu ayu-narezushi, Leuconostoc, Latilactobacillus, and Enterococcus were isolated as dominant genera. Isolated strains of Leuconostoc mesenteroides showed high growth inhibition activity against Staphylococcus aureus and Escherichia coli. The isolated strain, Enterococcus lactis EC52, could produce 1-aminobutyric acid (GABA). These results indicated that Enterococcus lactis and Leuconostoc mesenteroides were lactic acid bacteria, which have GABA-producing and antimicrobial activities, respectively, in traditional Gifu ayu-narezushi. [ABSTRACT FROM AUTHOR]

The current study addresses the critical issue of Listeria monocytogenes growth in raw sausage/meat products leading to human infections, most commonly listeriosis, which is known for its high fatality rate. This research focuses on the isolation, identification, and screening of lactic acid bacteria from various meat and fish products in Switzerland. In total, 274 lactic acid bacteria strains were isolated from 30 different products and were screened for their ability to inhibit Listeria monocytogenes growth, with 51 isolates demonstrating anti-Listeria activity at 8 °C, 15 °C, 25 °C, and 37 °C. Further experiments, using a meat model and a raw sausage challenge test, demonstrated that Leuconostoc carnosum DH25 significantly inhibited Listeria monocytogenes growth during the ripening and storage of the tested meat/sausage. This inhibitory effect was found to be attributed to the bacteriocins produced by Leuconostoc carnosum DH25 rather than factors like pH or water activity. The stability of the anti-Listeria substances was examined, revealing their resistance to temperature and pH changes, making Leuconostoc carnosum DH25 a promising protective culture for raw sausages. The genome sequencing of this strain confirms its safety, with no antibiotic resistance genes or virulence factors detected, and reveals the presence of the structural genes for the production of the bacteriocin LeucocinB-Ta11a. This study underscores the potential of LAB strains and their bacteriocins as effective tools for enhancing food safety and preventing Listeria monocytogenes growth in meat products, offering valuable insights into biocontrol strategies in the food industry. [ABSTRACT FROM AUTHOR]

This review highlights Leuconostoc citreum's promising possibilities as a proficient mannitol producer and its potential implications for sugar reduction, with a focus on its use in sourdough-based baked good products. Mannitol, a naturally occurring sugar alcohol, has gained popularity in food items due to its low calorie content and unique beneficial qualities. This study summarizes recent research findings and investigates the metabolic pathways and culture conditions that favor increased mannitol production by Leuconostoc citreum. Furthermore, it investigates the several applications of mannitol in baked goods, such as its function in increasing texture, flavor and shelf life while lowering the sugar content. Sourdough-based products provide an attractive niche for mannitol integration, as customer demand for healthier and reduced-sugar options increases. [ABSTRACT FROM AUTHOR]

Sugarcane must be processed quickly after being harvested because it is a destructible commodity. Harvested cane may degrade for a variety of reasons, including exposure to microbes, mechanical or manual harvesting, cultivar, maturity, cut-to-crush interval, and storage. Due to the quick loss of sucrose and deterioration after harvest, sugarcane needs to be treated at the right time and way. The higher sugar content of mature internodes offers the perfect conditions for microbial growth, which enters the harvested stalk through wounds or cut ends. The bacteria Leuconostoc spp. is primarily responsible for these post-harvest losses, which negatively affect sugar percent. The trials were carried out to assess the efficacy of Sodium metasilicate (SMS), Benzalkonium chloride (BKC), Nisin (Lactobacteria), and Neem sources on sugarcane for reducing the post-harvest degradation losses. An investigation is underway now to reveal that foliar spray of neem cake @ 5% + dried neem leaves extract @ 5% (in heaping) is the most effective and eco-friendly substance that might be able to significantly enhance sugar recovery. This treatment was comparable with the chemical formulation of SMS @ 2% (3 days before harvest) + BKC @ 2000 ppm (in heaping) which might be a consequence of controlling the proliferation of Leuconostoc spp. bacterium. Likewise, the juice obtained from these treatments has a lower rate of inclination in pH, reducing sugar, total soluble solids, titrable acidity index, invertase activity, higher sucrose, and commercial cane sugars (CCS) recovery, furthermore with relatively smaller losses in cane weight. Hence, these treatments offer a significant potential role in reducing post-harvest deterioration losses in the sugar industry. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) comprise a group of microorganisms responsible for developing the sensory and chemical characteristics of several foods and fermented products, particularly cheese. For this reason, after isolation and identification of LAB, validated protocols and procedures for their long-term preservation without compromising its integrity and technological properties, as well as methodologies aiming to assess their viability and integrity are paramount. This study aimed to isolate and identify autochthonous LAB from artisanal Adobera cheese and determine the effect of LAB cryopreservation with thioglycolate broth and glycerol on their viability, membrane integrity, and kinetics. Sixteen LAB were isolated and genetically identified from artisanal cheese samples; eleven of those strains were selected (genus Lactobacillus, Leuconostoc, Streptococcus, and Lactococcus) and included in the cryo-preservation assay. The initial average concentration of the bacterial suspensions was 6.89 log10 CFU mL−1; increasing to 8.9 log10 CFU mL−1 21 days later and slightly reduced at day 42 post-preservation (losses below one logarithm). About 77% of the cells maintained their membrane potential 180 days after their preservation and showed normal Kinetic parameters, maintaining normal adaptation times (Lag phase) and Log phases (9 h average), before reaching the stationary phase. The proposed protocol constitutes a viable alternative to the long-term preservation of different LAB genera because it keeps their viability and integrity. Using flow cytometry allowed the enumeration of viable LAB and provide evidence of the integrity of their membrane. [ABSTRACT FROM AUTHOR]

Leuconostoc encompasses a number of species that frequently appear in foods where they play different roles, ranging from ripening to spoiling. The number of available Leuconostoc genomes has recently increased and enabled the precise taxonomic and phylogenetic delineation of species. Nonetheless, a thorough investigation of the functions and the metabolic potential of Leuconostoc species has never been accomplished. In this study, all the currently available 553 Leuconostoc genomes were downloaded from NCBI GenBank and annotated utilizing specific tools in order to reconstruct the metabolic potential of the genus in terms of carbohydrate hydrolysis and fermentative pathways, transporters, and anabolic potential. The analysis revealed that species cluster based on their metabolic potential, showing unique adaptation and ecological roles. Pentose phosphate and phosphoketolase pathways were highlighted as the main ones of central metabolism. The various identified PTS and ABC transporters showed adaptability to different sugars. The metabolic diversity described in this study not only supports the role of Leuconostoc spp. in natural ecosystems but also highlights their potential in industrial applications, particularly in the fermentation industry where their ability to metabolize a wide range of substrates can be harnessed for the production of various fermented foods and bioproducts.

Raw milk from native small ruminant breeds in Epirus, Greece, is a valuable natural source of autochthonous lactic acid bacteria (LAB) strains with superior biotechnological properties. In this study, two bulk milks (RM1, RM2) from two local sheep yards, intended for traditional Kefalotyri cheese production, were preselected for bacteriocin-like antilisterial activity by in vitro tests. Their antagonistic LAB biota was quantified followed by polyphasic (16S rRNA gene sequencing; IGS for Enterococcus; a multiplex-PCR for Leuconostoc) identification of 42 LAB (RM1/18; RM2/24) isolates further evaluated for bacteriocin encoding genes and primary safety traits. Representative isolates of the numerically dominant mesophilic LAB were Leuconostoc mesenteroides (10) in both RMs, Streptococcus parauberis (7) in RM2, and Lactococcus lactis (1) in RM1; the subdominant thermophilic LAB isolates were Enterococcus durans (8), E. faecium (6), E. faecalis (3), E. hirae (1), E. hermanniensis (1), Streptococcus lutetiensis (2), S. equinus (1) and S. gallolyticus (1). Based on their rpoB, araA, dsr and sorA profiles, six Ln. mesenteroides strains (8 isolates) were atypical lying between the subspecies mesenteroides and dextranicum, whereas two strains profiled with Ln. mesenteroides subsp. jonggajibkimchii that is first-time reported in Greek dairy food. Two RM1 E. faecium strain biotypes (3 isolates) showed strong, enterocin-mediated antilisterial activity due to entA/entB/entP possession. One E. durans from RM1 possessed entA and entP, while additional nine RM2 isolates of the E. faecium/durans group processed entA or entP singly. All showed direct (cell-associated) antilisterial activity only, as also both S. lutetiensis strains from RM2 did strongly. Desirably, no LAB isolate was β-hemolyrtic, or cytolysin-positive, or possessed vanA, vanB for vancomycin resistance, or agg, espA, hyl, and IS16 virulence genes. However, all three E. faecalis from RM2 possessed gelE and/or ace virulence genes. In conclusion, all Ln. mesenteroides strains, the two safe, enterocin A-B-P-producing E. faecium strains, and the two antilisterial S. lutetiensis strains should be validated further as potential costarter or adjunct cultures in Kefalotyri cheese. The prevalence of α-hemolytic pyogenic streptococci in raw milk, mainly S. parauberis in RM2, requires consideration in respect to subclinical mastitis in sheep and the farm hygiene overall.

Dextran, a microbial metabolite of diverse molecular configurations, can be biosynthesized employing selected strains of characterized species of bacteria. Dextran molecules are secreted as an extracellular polysaccharide in the culture medium of the bacterial fermentation system. This microbially produced polymer of glucose possesses multi-faceted characteristics such as its solubility in different solvents and formation of dextran solutions of needed viscosity. Several preparations can be formulated for the desired thermal and rheological properties. Due to such multifunctional characteristics, dextran with different structural specifications is a desired polysaccharide for clinical, pharmaceutical, and food industry commercial applications. Dextran and its derivative products with various molecular weights, in a range of high and low, have established their uses in drug delivery and in analytical devices using columns packed with polysaccharide gel. Therefore, being a neutral raw material, the resourcefulness of dextran preparations of different molecular weights and linkages in their polymer configuration is important. For this purpose, several studies have been performed to produce this commercially important polysaccharide under optimized bacterial cultivation processes. This article aims to overview recently published research reports on some significant applications of dextran in the pharmaceutical and food industries. Studies conducted under optimized conditions in fermentation processes for the biosynthesis of dextran of diverse molecular configurations, which are responsible for its multifunctional properties, have been summarized. Concise information has been presented in three separate tables for each group of specific bacterial species employed to obtain this extracellular microbial polysaccharide. [ABSTRACT FROM AUTHOR]

This study identified and evaluated differences between microbiome compositions of the ileum and ceca of 1940 and 2016 white leghorn genetic strains fed representative contemporary diets from those times. Ileal and cecal samples were collected at 69 weeks of age. Alpha and beta diversity metrics were generated, and the Analysis of Composition of Microbiomes (ANCOM) was utilized to determine significantly different taxa. Ileum and ceca alpha diversity were significantly different (p = 0.001; Q = 0.001); however, no differences between genetic lineage were observed (p > 0.05; Q > 0.05). Beta diversity between the ileum and ceca and the genetic lines was significantly different (p = 0.001; Q = 0.001). The ANCOM of the ileum showed significant differences between Proteobacteria and Actinobacteriota phyla (p ˂ 0.05) and significant differences between Pseudomonas, Rhizobiaceae, Leuconostoc, and Aeriscardovia genera (p ˂ 0.05). For ceca ANCOM, Proteobacteria, Firmicutes, Actinobacteriota, and Euryarchaeota phyla were significantly different (p ˂ 0.05), with Firmicutes having the highest relative abundance across all groups, and there were significant differences in genera Pseudomonas, Leuconostoc, Alloprevotella, and Aeri scardovia, with Alloprevotella having the highest relative abundance. The results suggest that genetic makeup in conjunction with the nutritional composition influences the cecal and ileal microbiota of corresponding hens. [ABSTRACT FROM AUTHOR]

Some lactic acid bacteria (LAB) are capable of producing exopolysaccharides (EPS), which can be used in the dairy industry to reduce syneresis and improve the viscosity and texture of fermented products. The aim of the present study was to screen the EPS-producing capacity of 123 LAB strains isolated from fermented foods to search for those able to produce EPS with the optimal technological aptitude to be applied in non-fat set yogurt manufacture. They were grown on MRS-sucrose and assigned to ropy or mucoid phenotype depending on the appearance of the colonies. Twenty-five of them were selected and assayed for production of both cell-bound EPS (EPS-b) and EPS released to the medium (EPS-r). Those resulting in the most EPS producers (Levilactobacillus brevis UCLM-Lb47, Leuconostoc mesenteroides subsp. mesenteroides 6F6-12 and Leuconostoc mesenteroides subsp. mesenteroides 2F6-9) were used to manufacture non-fat set yogurts. These yogurts were analyzed for microbiological and physicochemical properties (pH, titratable acidity, total solids), water-holding capacity, apparent viscosity, and sensory characteristics during a 28-day cold storage period. The yogurts made with the selected strains showed higher values of water-holding capacity, EPS concentration, and viscosity in the mouth than the control yogurt, which presented a more fluid texture. The results obtained suggest that the three selected strains could be used to replace hydrocolloids in non-fat set yogurt formulation, obtaining a clean-label product that would improve consumer acceptance. [ABSTRACT FROM AUTHOR]

In this study, lactic acid bacteria (LAB) strains were isolated from traditional fermented pickles, and among the identified strains, Leuconostoc citreum HE29 with a strong slimy colony profile was further selected to determine the physicochemical and techno-functional properties of its exopolysaccharide (EPS). Glucose was the only sugar monomer in the core unit of EPS HE29 detected by HPLC analysis, and glucan HE29 revealed 7.3 kDa of molecular weight. Structural characterization of glucan HE29 by 1H and 13C NMR spectroscopy analysis demonstrated that EPS HE29 was a dextran-type EPS containing 5.3% levels of (1 → 3)-linked α-D-glucose units. This structural configuration was also supported by FT-IR analysis, which also demonstrated the functional groups within the dextran HE29 structure. In terms of thermal properties detected by TGA and DSC analysis, dextran HE29 demonstrated a degradation temperature of around 280 °C, showing its strong thermal features. A semi-crystalline nature was observed for dextran HE29 detected by XRD analysis. Finally, AFM and SEM analysis revealed tangled network-like properties and web-like branched structures for dextran HE29, respectively. These findings suggest the importance of plant-based fermented products as LAB sources in obtaining novel EPS structures with potential techno-functional roles. [ABSTRACT FROM AUTHOR]

The preservation of raw meat products is a paramount concern within the food industry, spoilage and pathogenic bacteria pose significant challenges in maintaining the freshness and safety of raw beef meat. This study was focused on the exploration of the effectiveness of partially purified bacteriocins (ppBA) from three Leuconostoc strains isolated from camel's milk for raw beef meat preservation by active packaging film. The active packaging film containing ppBA bacteriocin was developed using lowdensity polyethylene LDPE film as the packing material through a soaking method. After a proteomic characterization the identification of distinct Leuconostoc strains as Leuconostoc lactis TW88, Leuconostoc mesenteroides KW83, and Leuconostoc mesenteroides BW46. All the tested strains were active against more than four indicators' bacteria presented by an inhibition zone up to 20mm with Bacillus cereus, 23,5mm with Enterococcus faecalis, 22,5mm with Listeria innocua, 25mm with Pseudomonas aeruginosa and 23,5mm with Escherichia coli. The activated film demonstrated antibacterial effects against seven pathogenic bacteria. When in contact with the meat matrix, the active LDPE film released the bacteriocins, which exhibited residual activity under various simulated conditions. These activated films displayed biopreservative efficacy in controlling the growth of pathogens in meat. The bacteriocin-activated film can be utilized as a packing material to control the growth of spoilage and pathogenic bacteria in food, ultimately extending the shelf life of food products. [ABSTRACT FROM AUTHOR]

Peanuts contain nutritionally relevant levels of protein, yet are poorly digestible. Fermentation is a promising technique to boost legume protein quality, but its effect on the protein quality of raw peanuts has not been investigated. This study aimed to assess the impact of fermentation on the in vitro protein digestibility and free amino acid profile of cooked peanut slurry (peanut to water ratio 1:1). Cultures used were Propionibacterium freudenreichii subsp. globosum and a commercial fresh cheese culture that contained Lactococcus lactis subsp. cremoris, lactis, lactis biovar diacetylactis, and Leuconostoc, fermenting at 38 °C for 48 h. Samples fermented with the combination of cultures showed higher protein digestibility, as well as softer texture. Significant increases were observed only in the sample fermented with the fresh cheese culture. While the fresh cheese culture improved the free amino acid profile after fermentation, the combination of the cultures decreased all free amino acid concentrations except for glutamine, alanine, and proline. The observed increases in in vitro protein digestibility and the free amino acid profile may be attributed to the proteolytic activities of the cultures. [ABSTRACT FROM AUTHOR]

Background: Many native fermented foods in Latin America are made by indigenous communities through processes that preserve their traditions. Among these products is champús, a fermented drink or dessert native to Colombia, Ecuador, and Peru. It has a characteristic flavor between sweet and sour with a low alcohol content, is made from cereals such as corn, wheat, or a mixture of these, and can include fruits and spices. Objectives: This research evaluated the microbiological, physicochemical, and sensory quality characteristics of champús to revalue the consumption of traditional foods. Methods: For this purpose, the microbiological safety criteria, fermenting microorganisms, and physicochemical and sensory parameters were evaluated for two batches of champús prepared by five producers and taking samples at different stages. Results: It was found that the average temperature and relative humidity for processing were between 16.5 ± 2.56 °C and 61.6 ± 9.14 %, respectively, and the products exceeded microbiological criteria such as total coliforms and some microbiological criteria for Escherichia coli and Staphylococcus aureus. There was also a high prevalence of lactic acid bacteria and yeasts throughout the process, with the occurrence of the genera Weissella, Leuconostoc, and Lactobacillus. The presence of organic acids (lactic, acetic, and propionic) and ethanol was evidenced. Champús seems to be a source of calcium, phosphorus, and free amino acids. Conclusions: This information provides a basis to propose improvement plans for small producers and, at the same time, to conduct more detailed studies on the native microbiota of champús. [ABSTRACT FROM AUTHOR]

We demonstrated several technological aptitudes and sensitivity of lactic acid bacteria (Leuconostoc) isolated from the raw milk of cows. We explained the experiments in detail to get the reader to understand what kinds of technology can be used for testing bacteria. Lactic acid bacteria are used in the production of dairy products to increase their shelf life and improve their organoleptic and nutritional properties. Leuconostocs is a heterofermentative bacterium that produces lactic acid, acetic acid or ethanol, and carbon dioxide. A collection of 138 strains of lactic acid bacteria were isolated from the raw milk of cows in the region of eastern Morocco. 38 strains were identified as Leuconostocs. Their subspecies are 16 Mesenteroides, 11 Dextranicum, and 11 Cremoris. Our study was interested in the technological aptitude of this genus looking for the production of dextran and growth in milk with additional sunflower dye, as well as the acidifying, flavoring, thickening, coagulating, proteolytic activity in solid medium and Lipolytic activity. This work also consisted of studying the profile of the resistance and the sensitivity of these strains to antibiotics. [ABSTRACT FROM AUTHOR]

A novel Chinese-style sausage with Chinese traditional fermented condiments used as additional ingredients is produced in this study. The aim of this study was to investigate the microbial community's structure, the volatile flavor substances and their potential correlation in the novel Chinese sausage. High-throughput sequencing (HTS) and solid-phase microextraction-gas chromatography-mass spectrometry (GC-MS) were, respectively, used to analyze the microbial diversity and volatile flavor substances of the novel Chinese-style sausage during storage. The results showed that Firmicutes, Proteobacteria and Actinobacteria were the predominant bacterial genera, and Hyphopichia and Candida were the predominant fungal genera. A total of 88 volatile flavor substances were identified through GC-MS, among which 18 differential flavor compounds were screened (VIP > 1), which could be used as potential biomarkers to distinguish the novel sausages stored for different periods. Lactobacillus exhibited a significant negative correlation with 2,3-epoxy-4,4-dimethylpentane and acetoin and a significant positive correlation with 2-phenyl-2-butenal. Hyphopichia significantly positively correlated with ester. Leuconostoc significantly positively correlated with ethyl caprate, ethyl palmate, ethyl tetradecanoate and ethyl oleate while it negatively correlated with hexanal. This study provides a theoretical basis for revealing the flavor formation mechanisms and the screening of functional strains for improving the flavor quality of the novel Chinese-style sausage. [ABSTRACT FROM AUTHOR]

Abstract The purpose of this review was to describe how adaptive laboratory evolution (ALE) can provide improvement to lactic acid bacteria (LAB) strains for their application in industrial biotechnological processes. This review was carried out according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) approach, incorporating the ScienceDirect and Scopus databases. The literature search yielded 4,167 (ScienceDirect) and 27 (Scopus) articles, which were reduced to 12 after applying the inclusion /exclusion criteria. The studies revolved around LAB of the genera Lactobacillus, Lactococcus, Leuconostoc and Enterococcus and the application of ALE experiments in batch mode, fed-batch mode, or both, and aimed to produce strains with increased lactic acid production capabilities, higher cell viability, and multiple-stress tolerance. The studies demonstrated that ALE is an efficient approach for strain modification towards desired phenotypic functions and does not require genetic engineering. Knowledge of the cellular and molecular responses of microorganisms to stress enables an understanding of the adaptation mechanisms of LAB strains for survival and increased production of metabolites throughout ALE experiments.

This study aimed to investigate the beneficial effects of Momordica charantia (MC) extract and MC fermented with Leuconostoc mesenteroides MKSR (FMC) on high-fat and high-cholesterol diet-induced metabolic complications. Male C57BL/6 mice were divided into six groups: normal diet (ND), high-fat and high-cholesterol diet (HFCD), HFCD with 1% MC extract (HFCD + 1M), HFCD with 4% MC extract (HFCD + 4M), HFCD with 1% fermented MC (HFCD + 1F), and HFCD with 4% fermented MC (HFCD + 4F). After 12 weeks of dietary intervention, the consumption of MC fermented with L. mesenteroides MKSR resulted in significant decreases in white adipose tissue weights (epididymal adipose tissue and retroperitoneal adipose tissue), serum alanine aminotransferase activity, and hepatic triglyceride levels. FMC also lowered total hepatic cholesterol content, improved glucose clearance during the oral glucose tolerance and insulin tolerance tests, and increased fecal cholesterol efflux from the enterohepatic circulation. Furthermore, the FMC notably increased hepatic mRNA expressions, which may indicate a compensatory mechanism against induced cholesterol efflux. Moreover, FMC induced both adipogenic (sterol regulatory element-binding protein 1c) and lipolytic (lipoprotein lipase, peroxisome proliferator-activated receptor alpha, and adiponectin) mRNA expressions. These findings suggest that fermentation with the probiotic L. mesenteroides MKSR enhances the beneficial effects of MC, preventing metabolic complications associated with a high-fat diet. [ABSTRACT FROM AUTHOR]

Cheese is obtained by the coagulation of milk, followed by maturation under the action of microorganisms which are responsible for the development of physicochemical and organoleptic characteristics of cheese. Among various microorganisms, lactic acid bacteria (LAB) play an essential role in establishing sensory characteristics of the cheese. In Cameroon, the effect of isolated LAB on the sensory characteristics of cheese produced from local cow milk has not yet been investigated. Therefore, the present work aimed to isolate LAB and evaluate their influence on the physicochemical and sensory characteristics of locally produced soft cheeses. Four strains of LAB were isolated and identified as Enterococcus sp.1, Enterococcus sp.2, Pediococcus sp., and Leuconostoc sp. These isolates were combined in batches for production of cheeses, including Frm 741 (Enterococcus sp.1 and Enterococcus sp.2), Frm 891 (Enterococcus sp.2 and Leuconostoc sp.), Frm 683 (Pediococcus sp. and Enterococcus sp.1), Frm 425 (Pediococcus sp. and Leuconostoc sp.), Frm 503 (Pediococcus sp. and Enterococcus sp.2), Frm 439 (Leuconostoc sp. and Enterococcus sp.1), and Frm 625 (Enterococcus sp.1, Enterococcus sp.2, Leuconostoc sp., and Pediococcus sp.). Cheese produced from the combination of Enterococcus sp.1 and Enterococcus sp.2 (Frm 741), unlike the others, did not drain properly throughout the production process. However, all products showed excellent microbiological quality in relation to biological contaminants, such as Salmonella, staphylococci, and coliforms. Moreover, cheese Frm 425 was most appreciated by consumers for its sweet taste, yellow colour, pleasant smell, and low acidity (51.7°D). On the other hand, cheese Frm 439 was least appreciated by consumers owing to its bad odour, bitter taste, and high acidity (144.9°D). Taken together, the present work demonstrated that the isolated LAB could be used to produce soft cheese with a natural rind and unique sensory characteristics that are appreciated by Cameroonian consumers. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hurood cheese (namely Hurood) is a traditional acid-coagulated cheese in China. This work investigated key aroma compounds and their potential correlations with dominant species of Hurood sampled from three distinct geographical origins. Key aroma compounds were determined according to Gas chromatography–mass spectrometry (GC–MS), gas chromatography–olfactometry (GC–O), and relative odor active values (ROAVs) analyses. In addition, 16S rDNA sequencing was used to identify the dominant species. Furthermore, Pearson correlation analysis was used to determine the potential relationships between key aroma compounds and dominant species. A total of 31 key aroma compounds were identified in the Hurood samples from three regions. Lactobacillus paracasei, Lactobacillus crispatus, and Leuconostoc citreum were found to be significantly correlated with the key aroma compounds (p < 0.05) and were identified as the core species. This study shows the link between the presence of presumptive functional core microbes and the unique aroma profiles of this traditional dairy product. [ABSTRACT FROM AUTHOR]

Bacterial exopolysaccharides (EPSs) share their compositional and structural features with plant dietary fibers. Therefore, analysis of bacterial EPSs produced during fermentation of fruit or vegetables interferes with that of plant fibers. To get rid of this effect, bacteria were grown on a solid medium containing fruit juice or purée and EPSs were recovered in a quantitative dependent manner and were quantified with the phenol-sulfuric acid colorimetric method. The protocol was assayed both on MRS medium and fruit-based media, with three bacterial strains from two species, Leuconostoc pseudomesenteroides 56 and Weissella cibaria 21 and 64. With that method, differences in EPS production levels were shown according to the strain and cultivation conditions, such as sucrose content and pH. Complementary analysis with NMR indicated that glucose and sucrose were partly recovered with EPSs, pointing out the requirement for a further purification step. It also showed that EPSs' ramified structure differed according to the strain and the fruit used in the medium. This method for EPS recovery is helpful to select strains and to pilot EPS production during lactic fermentation of fruit or vegetable foods. [ABSTRACT FROM AUTHOR]

Cooked ham is a popular, ready-to-eat product made of pork meat that is susceptible to microbial growth throughout its shelf life. In this study, we aimed to monitor the microbial growth and composition of nine vacuum-packed cooked ham lots using plate counting until the microbial limit of 7.4 log10 AMC/LAB CFU/g was exceeded. Eight out of nine lots exceeded the microbial limit after 20 days of storage. Lactic acid bacteria strains, particularly Leuconostoc carnosum and Latilactobacillus sakei, prevailed in vacuum-packed cooked ham. Leuconostoc carnosum 2 (Leuc 2) and Latilactobacillus sakei 4 (Sakei 4) were isolated from raw meat and the post-cooking area of the food processing facility. Carbohydrate utilization patterns of Leuc. carnosum PFGE types isolated from raw meat and the food processing environment differed from those isolated from cooked ham. These findings demonstrate how raw meat and its processing environment impact the quality and shelf life of cooked ham. [ABSTRACT FROM AUTHOR]

Background: Bacteriocins are peptides with antibacterial properties that are released by lactic acid bacteria and affect genetically closely related bacteria. Settled bacteriocin-producing probiotics in the GI tract may contribute to bacteriocin formation, which can lead to pathogen inhibition and immune system regulation. The purpose of this study is to evaluate the probiotic capabilities of bacteriocin-producing LAB isolated from malted barley, Pediococcus acidilactici HW01, and Leuconostoc citreum HW02. Results: Both strains could survive in harsh GI conditions such as low pH, bile salt, pepsin, and lysozyme. Furthermore, exhibited non-haemolytic activity and tetracycline and erythromycin susceptibilities. In vitro adhesion of HW01 and HW02 strains to HT-29 cells was 76.28 and 75.99%, respectively. Auto-aggregation ability of HW01 and HW02 was about 14%, but their ability to aggregate with pathogens (Escherichia coli, Salmonella enterica ser. Typhimurium, Staphylococcus aureus and Listeria monocytogenes) ranged from 32.0% to 43.5%. Regarding the anti-inflammatory effect, heat-killed bacteriocin-producing strains suppressed the mRNA expression levels of cytokines and chemokines in RAW 264.7 macrophages induced by LPS (P < 0.005). Conclusions: Bacteriocin-producing P. acidilactici HW01 and Leu. citreum HW02 may be good probiotic candidates. [ABSTRACT FROM AUTHOR]

The Kimoto -style fermentation starter is a traditional preparation method of sake brewing. In this process, specific microbial transition patterns have been observed within nitrate-reducing bacteria and lactic acid bacteria during the production process of the fermentation starter. We have characterized phylogenetic compositions and diversity of the bacterial community in a sake brewery performing the Kimoto -style fermentation. Comparing the time-series changes with other sake breweries previously reported, we found a novel type of Kimoto -style fermentation in which the microbial transition differed significantly from other breweries during the fermentation step. Specifically, the lactic acid bacteria, Leuconostoc spp. was a predominant species in the late stage in the preparation process of fermentation starter, on the other hand, Lactobacillus spp., which plays a pivotal role in other breweries, was not detected in this analysis. The discovery of this new variation of microbiome transition in Kimoto -style fermentation has further deepened our understanding of the diversity of sake brewing. [ABSTRACT FROM AUTHOR]

Pulque is a traditional Mexican fermented beverage associated with numerous health benefits. Over time, there has been considerable interest in studying the bacterial diversity of pulque, and microbial characterization has been carried out using traditional microbiological and molecular methods. Therefore, the objective of this research was to characterize the microbiota of artisanal pulque obtained from the Zacatlán region in Puebla, México, by the means of Illumina sequencing, and to compare it with the microbial diversity of aguamiel (sap before fermentation), commercial pulque (supplemented with additives to increase its yield), and its seed (batch of pulque previously fermented). An analysis of the Shannon index showed medium diversity for both aguamiel and pulque samples (score > 2), while the Chao 1 index exhibited a non-significant difference between them. On the other hand, a principal components analysis confirmed the role of the seed as an essential inoculum to define the microbial diversity of pulque, emphasizing the importance of its preservation as a quality standard during the elaboration process. In addition, results showed that the dominant phyla in artisanal and commercial pulque were Firmicutes and Bacteroidetes. As the fermentation process progressed, it was possible to observe an increase in the population of lactic acid bacteria (LAB) in both types of pulque compared to those detected in aguamiel. Of these, the species Lactobacillus, Leuconostoc, and Lactococcus represented almost 95% of the total LAB. Finally, even though the safety of pulque has been in question due to its non-aseptic manufacturing process, the present study confirmed that less than 1% of its microbiota corresponds to the genera with a pathogenic potential such as γ-proteobacteria (Enterobacter and Hafnia), which decreases as the fermentation process advances. [ABSTRACT FROM AUTHOR]

Momordica charantia (MC; commonly known as bitter melon) was fermented with Leuconostoc mesenteroides MKJW, MKSR, and KCTC 3719 (LM), and Leuconosoc citreum KCTC 3526 (LC), and their anti-diabetic, anti-dementia, and antioxidant activities were evaluated. The fermentation was performed for 24 h at 30 °C, and non-fermented MCs (CON1 and CON2) were included for comparison. All fermented MCs produced lactic acids, mannitol, dextran, and oligosaccharides. The highest amount of mannitol (34.76 mg/mL) and lactic acids (10.42 mg/mL) were produced in MKSR-MC, and the highest amount of dextran (22.37%) was produced in MKJW-MC. MKSR-MC showed complete α-glucosidase inhibition (99.91%), but it did not show a significant change in α-amylase inhibition (24.43%) compared to non-fermented MC (20.14%) (p > 0.05). It was also high in acetylcholinesterase inhibition (55.24%) compared to other fermented MCs (31.21–44.46%). Fermentation increased butyrylcholinesterase inhibition, but no significant differences were observed among the groups. Therefore, our results indicated that MKSR-fermented MC might be used as a non-dairy probiotic plant extract to achieve multi-health functional activities such as anti-diabetic, anti-dementia, and antioxidant activities. [ABSTRACT FROM AUTHOR]

Breast milk was long considered a sterile environment, but now it is known to harbor many bacteria that will shape the newborn microbiota. The benefits of breastfeeding to newborn health are, on some level, related to the presence of beneficial bacteria in human milk. Therefore, this study aims to investigate and isolate potential probiotics present in human milk that might be associated with improved health in infants, being potential candidates to be used in simulated human milk formula. Milk samples of 24 healthy mothers were collected at three time points: 30 min (colostrum), 5–9 days (transitional milk), and 25–30 days (mature milk) postpartum. Samples were evaluated by culturing, and the isolated bacteria were identified by MALDI-TOF MS and 16S DNA sequencing. In vitro screening for probiotics properties was performed, and the potential probiotics were mono-associated with germ-free mice to evaluate their ability to colonize the gastrointestinal tract. The microorganisms were submitted to the spray-drying process to check their viability for a potential simulated milk formula production. Seventy-seven bacteria were isolated from breast milk pertaining to four bacterial genera (Staphylococcus, Streptococcus, Leuconostoc, and Lacticaseibacillus). Four potential probiotics were selected: Lacticaseibacillus rhamnosus (n = 2) and Leuconostoc mesenteroides (n = 2). Isolates were able to colonize the gastrointestinal tract of germ-free mice and remained viable after the spray-drying process. In conclusion, breast milk harbors a unique microbiota with beneficial microorganisms that will impact the newborn gut colonization, being an essential source of probiotic candidates to be used in a formula of simulated maternal milk. [ABSTRACT FROM AUTHOR]

Abstract Background Leuconostoc gelidum and Leuconostoc gasicomitatum have dual roles in foods. They may spoil cold-stored packaged foods but can also be beneficial in kimchi fermentation. The impact in food science as well as the limited number of publicly available genomes prompted us to create pangenomes and perform genomic taxonomy analyses starting from de novo sequencing of the genomes of 37 L. gelidum/L. gasicomitatum strains from our culture collection. Our aim was also to evaluate the recently proposed change in taxonomy as well as to study the genomes of strains with different lifestyles in foods. Methods We selected as diverse a set of strains as possible in terms of sources, previous genotyping results and geographical distribution, and included also 10 publicly available genomes in our analyses. We studied genomic taxonomy using pairwise average nucleotide identity (ANI) and calculation of digital DNA-DNA hybridisation (dDDH) scores. Phylogeny analyses were done using the core gene set of 1141 single-copy genes and a set of housekeeping genes commonly used for lactic acid bacteria. In addition, the pangenome and core genome sizes as well as some properties, such as acquired antimicrobial resistance (AMR), important due to the growth in foods, were analysed. Results Genome relatedness indices and phylogenetic analyses supported the recently suggested classification that restores the taxonomic position of L. gelidum subsp. gasicomitatum back to the species level as L. gasicomitatum. Genome properties, such as size and coding potential, revealed limited intraspecies variation and showed no attribution to the source of isolation. The distribution of the unique genes between species and subspecies was not associated with the previously documented lifestyle in foods. None of the strains carried any acquired AMR genes or genes associated with any known form of virulence. Conclusion Genome-wide examination of strains confirms that the proposition to restore the taxonomic position of L. gasicomitatum is justified. It further confirms that the distribution and lifestyle of L. gelidum and L. gasicomitatum in foods have not been driven by the evolution of functional and phylogenetic diversification detectable at the genome level.