Search

Background Fruit, vegetables, flowers, and ethnic beverages may be a source of microbial species with techno-functional and health-promoting properties. Scope and approach This review explored the added-value microorganisms isolated from unconventional sources and their techno-functional and probiotic properties. Fruits (strawberry, guava, apple, peach, grape, and papaya), vegetables (peppers, corn, zucchini, lettuce, cucumber, coffee beans, and olives), flowers (narcissus, pink rose, red rose, yellow rose, and sunflower), and ethnic fermented beverages (tchapalo, taruba, cauim, chicha, caxiri, kombucha, and water kefir) are source of lactic acid bacteria (Lactobacillus and amended genera, Leuconostoc, Enterococcus, Pediococcus, Fructobacillus, and Weissella) and yeasts (Saccharomyces, Candida, Pichia, Rhodotorula, Torulaspora, Cryptococcus, Hansenula, and Debaromyces). Key findings and conclusions Strains isolated from unconventional sources showed antimicrobial capacity, production of bioactive metabolites, and technological properties, suggesting their utilization as biopreservatives in food products or against phytopathogens, and for improving the nutritional value and sensory characteristics of food products. Their utilization as starter cultures in fermented foods may decrease the fermentation time and improve the products' characteristics. Some strains showed probiotic potential, presenting important adhesion and auto and co-aggregation properties, cell surface hydrophobicity, safety, and resistance to the gastrointestinal tract. These probiotic cultures showed anti-hypertensive, antilipidemic, immunomodulatory, and anti-diabetic properties in in vitro assessments or animal models. However, clinical studies are necessary to demonstrate the health effects in humans. In conclusion, cultures isolated from unconventional sources have a high potential for use in processing and functionalization of foods and can be alternative tools for developing vegan probiotic products.

30 Páginas.-- 6 Figuras.-- 1 Tabla, In this work, we have used a metataxonomic analysis to study the bacterial biodiversity in three types of commercial dressing and ingredients habitually used in table olive packaging. The bioinformatics analysis showed that salt samples (marine and spring) had the highest biodiversity indexes, followed by the aromatic herbs (thyme, oregano, and fennel) and finally by fermented dressing samples (garlic, pepper, and pepper paste). In salt samples, a significant high presence of Cytophagia, Sphingobacteria, Deltaproteobacteria and Halobacteria classes was observed. On the contrary, the presence of Bacilli class in fermented dressing samples was significantly higher compared to the other samples. Finally, the abundance of Gammaproteobacteria was statistically higher in the samples of herbs. At genus or family taxonomic level, Pseudomonas and diverse non-assigned genus of the Enterobacteriaceae family predominated in many samples of herbs. In fermented dressing samples, diverse genus belonging to the Enterobacteriaceae family appeared in a high relative abundance in pepper paste and garlic, and presence of Vibrio sp. was detected in pepper. However, Lactobacillus, Weisella, and Pediococcus were the predominant genera found in many of these fermented samples. Salinibacter was the most representative genus in both types of salt samples. Multivariate analysis (PCA) of the metataxonomic data sets discriminated well the samples belonging to the three different groups, showing a high proportion of sequences shared by samples-group. This survey reports for the first time the presence of new bacterial species not previously related with table olive processing, as well as the presence of others which could compromise the stability of olive packaging., The research was funded by the Spanish Government (Project OliFilm AGL-2013-48300-R: www.olifilm.science.com.es) AB-C and JB-G thanks the Spanish Ministry of Economy and Competitiveness for their FPI grant and JDC-Incorp. contract, respectively. BC-D thanks the Andalusian Ministry of Economy, Science and Innovation by her pre-doctoral contract.

The microbial population in koumiss, a traditional Mongolian fermented beverage, plays a vital role in its nutritional value, beneficial functions, and flavour. We used the Illumina MiSeq platform to investigate the successive bacterial communities produced during koumiss fermentation; dynamic changes in chemical composition of koumiss were also analysed. The correlation between bacterial species and major metabolites was then evaluated. The dominant bacterial species identified during the process of koumiss fermentation were Lactobacillus helveticus, Streptococcus parauberis (phylum Firmicutes), and Acetobacter pasteurianus (phylum Proteobacteria). Lactose content decreased during fermentation, whereas lactic acid, acetic acid, and butyric acid content increased, resulting in decreased pH. The changes in lactose, lactic acid, butyric acid, and pH were mainly correlated with the presence of the bacterial genera Acetobacter, Leuconostoc, Pediococcus, and Bacteroides. Information from these results could advance our understanding of koumiss fermentation, and also help improve the safety, flavour, and therapeutic applications of koumiss.

This study investigates the efficiency of starch nano-particles in comparison with native starch for encapsulation of probiotic bacterial cells (Pediococcus acidolactici). Bacterial cell-death after encapsulation, viability and bioactivity retention under simulated gastro-intestinal conditions (SGID) were studied. Encapsulation in native starch showed higher viable cells (2.65 log CFU/g) ascompared to those encapsulated in starch nano-particles (1.47 log CFU/g) (P

Untreated agricultural waste results in significant environmental pollution and reduces economic efficiency in The Three Gorges Reservoir Region. Ensiling is a method used to improve biowaste-to-resource systems and enhance the efficiency of resource recycling. Nutrient-rich citrus waste are suitable raw material for ensiling in China, but unsuitable for large-scale ensiling. In this study, citrus waste and other agricultural by-products were used to ensile as livestock feed in a family-scale silo. Spatial variation in microbiome composition and silage quality was analyzed in the bunker silo. From the top to the bottom of the silo, the crude protein, crude fiber, and pectin contents all increased, while the loss rate of dry matter decreased, indicating that the silage quality was better in the lower section of the silo. Spatial variation in temperature, pH, and moisture significantly influenced silage quality by influencing the composition of the microbiome. Undesirable Enterobacteriaceae and Trichocomaceae were replaced by Lactobacillus, Saccharomycetaceae, Sphingobium, and Pediococcus during ensiling. Proteolysis was mainly due to the decomposition of crude protein and further hydrolysis of soluble protein by Sphingobium, Brevundimonas, and fungi. Crude fiber and pectin were primarily degraded by unclassified_o_Saccharomycetales and norank_o_Eurotiales. The pH of the silage decreased from the top to the bottom of the silo as well from the outside to the center, which is attributed to the presence of Lactobacillus and Pediococcus. More homofermentative lactic acid bacteria should be added to raw materials that are positioned higher in the bunker silo to improve silage quality. The reuse of agricultural waste as silage in Changshou Agricultural Park of the Three Gorges Reservoir Region could result in increase in annual profits of $8,282.50 USD; however, the waste handling expenses totaled $8,416.00 USD. The application of this BTR method will reduce the shortage of fermented feed and result in significant economic benefits.

A traditional Thai fermented pork, nham, is a product popularly consumed in Thailand. Fermentation of the protein-rich product by uncontrolled bacterial community can result in high amounts of hazardous biogenic amines (BA). This study aimed to unveil dynamics of microbial community and its relation to BA accumulation in nham. Three batches of nham were analyzed for pH, lactic acid bacteria population, concentrations of organic acids and BA. Bacterial communities were analyzed by pyrosequencing of 16S rRNA gene amplicons. In all batches, pH dropped to the quality standard of nham (≤4.6) within 3–5 days by production of lactic acid and acetic acid. Initial BA levels varied batch-by-batch and increased with fermentation time. In the highest quality batch, levels of histamine, tyramine, and total BA were within the recommended safety limits (200, 100 and 1000 mg/kg, respectively) throughout the 10-days study. However, in other batches, unsafe levels of tyramine and total BA were found after 5 days of fermentation. The results indicated that over-fermentation and inferior conditions of ingredients increased risk due to high levels of BA. Lactobacillus, Lactococcus, Pediococcus and Weissella were prevalent and comprised >90% of total bacteria during fermentation. Weissella was predominant in the batch with low BA while Lactobacillus and Pediococcus were predominant in the higher BA batches. A negative correlation between Weissella dominance and total BA was observed (r = −0.90, p = .003). A 10% increase in dominance of Weissella was associated with 75–170 mg/kg decrease in total BA. W. hellenica was the species prevalent only in low BA batch. Therefore, W. hellenica isolates were suggested as subjects for future study to develop efficient starter culture securing safety of nham.

To improve the quality of potato steamed bread, the microbial diversity of 5 different sourdoughs and their effects on potato steamed bread were studied. The proximate composition analysis differentiated the Chinese traditional sourdough (CTS) with different levels of nutrients and pH (3.82–6.22). High-throughput sequencing revealed the predominant microbes in the five CTSs were Lactobacillus, Pediococcus, and Wickerhamomyces. Similarities of bacterial and fungal compositions were observed within them. The fermentation rheological results suggested CTS1 and CTS3 had higher total gas production value (2355.5 mL and 2249.5 mL respectively) than baker’s yeast. CTSs resulted in various effects on the appearance and texture properties of potato steamed bread with CTS1 showed the highest specific volume (2.38 mL/g) and sensory score (7.43). Wickerhamomyces significantly correlated with the total gas production, hardness, resilience, and lightness of potato steamed bread. The study suggested a potential application of CTSs in fermented potato staple foods.

The objective of this study was to evaluate the silage fermentation and bacterial community of bur clover, annual ryegrass and their mixtures in south of China. Bur clover, annual ryegrass and their mixtures were ensiled without additive (control), or with lactic acid bacteria inoculant (LABi, 106 cfu/g of fresh weight) and formic acid (FA, 3 mL/kg of fresh weight) for 60 d of fermentation. Untreated bur clover displayed high bacterial diversity resulting in a poor fermentation. LABi and FA reduced bacterial diversity and enriched the relative abundance of Lactobacillus, Pediococcus or Sporolactobacillus species during ensiling, resulting in improved silage fermentation. Annual ryegrass contained relative abundance of Proteobacteria and Clostridium species, and produced more butyric acid. This study confirmed that LABi and FA could reduce microbial diversity and improve silage quality; and Clostridium species produced butyric acid which caused a poor fermentation.

Defatted rice bran (DFRB) is an inexpensive and easily available agricultural byproduct. Existence of anti-nutritional factors (ANFs), high fiber and low protein content, susceptible to oxidation and rancidity make DFRB currently underutilized. In this study, Bacillus subtilis with high enzyme activities, Saccharomyces cerevisiae with high single-cell proteins concentration and Lactiplantibacillus plantarum with excellent acid secreting capacity were screened to co-fermented DFRB with phytase, and multiple physicochemical analyses combined with high-throughput sequencing were applied to provide insights into the dynamics of the physicochemical characteristics and the complex microbiome during the two-stage co-fermentation of DFRB. The results showed that co-fermentation effectively improved the nutritional value by degrading ANFs (trypsin inhibitors and phytic acid), fiber (acid detergent fiber and neutral detergent fiber) and allergenic protein, and increasing the trichloroacetic acid soluble protein, amino acids and organic acid. In addition, co-fermentation prevented lipid oxidation by enhancing antioxidant activity and reducing the activity of lipase and lipoxygenase. High-throughput sequencing results suggested that co-fermentation optimized microbial community of DFRB by increasing desirable Lactobacillus, Pediococcus, Saccharomyces and Talaromyces and reducing undesirable bacteria (Enterobacter and Pseudomonas) and animal and plant-pathogenic fungi (Blumeria, Alternaria, Fusarium, etc.). Furthermore, high-throughput sequencing and gas chromatography-mass spectrometry (GC-MS) were adopted to predict microbial metabolic functions and metabolic pathways during whole DFRB co-fermentation.

Sichuan Paocai (SCP), a traditional fermentationed food, possesses unique flavours driven by various microbiota in fermentation ecosystems. However, the association between these microbiota and flavours is poorly understood. Here, we measured the structural dynamics of the microbial diversity and flavour compounds during SCP fermentation (0–7 days) using high-throughput sequencing and flavour analyses. Firstly, a total of 90 bacteria and 135 fungi were identified. The results showed that fermentation process was initiated by environmental microorganisms, such as Micrococcaceae, followed by a heterolactic fermentation phase dominated by Leuconostocaceae, and finally succeeded by homolactic fermentation led by Lactobacillaceae. Secondly, 6 organic acids, 12 amino acids and 86 volatile flavours were detected. The fermentation process was divided into 4 stages based on flavours: Day 0; Days 1–3; Days 4–6; and Day 7. Analysis of the correlation between microbiota and flavours indicated that bacteria contributed more to flavours formation than did fungi, and Lactobacillus, Leuconostoc, Achromobacter and Pediococcus were closely correlated with flavours. This study provides a systematic method for understanding the characteristics of fermented foods and useful guidelines for screening of strains that produce desirable flavours and functional substances.

Daqu is a traditional fermentation starter for the production of baijiu and vinegar. It is an important saccharifying and fermenting agent associated with alcoholic fermentation and also a determining factor for the flavour development of these products. Bacterial and yeast isolates from a traditional fermentation starter ( Fen-Daqu ) were examined for their amylolytic activity, ethanol tolerance and metabolite production during sorghum-based laboratory-scale alcoholic fermentation. The selected strains ( Bacillus licheniformis , Pediococcus pentosaceu s, Lactobacillus plantarum , Pichia kudriavzevii , Wickerhamomyces anomalus , Saccharomyces cerevisiae , and Saccharomycopsis fibuligera ) were blended in different combinations, omitting one particular strain in each mixture. 1 H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistical analysis was used to investigate the influence of the selected strains on the metabolic changes observed under the different laboratory-controlled fermentation conditions. Principal component analysis showed differences in the metabolites produced by different mixtures of pure cultures. S. cerevisiae was found to be superior to other species with respect to ethanol production. S. fibuligera and B. licheniformis converted starch or polysaccharides to soluble sugars. Lactic acid bacteria had high amylolytic and proteolytic activities, thereby contributing to increased saccharification and protein degradation. W. anomalus was found to have a positive effect on the flavour of the Daqu -derived product. This study highlights the specific functions of S. cerevisiae , S. fibuligera , B. licheniformis , W. anomalus and lactic acid bacteria in the production of light-flavour baijiu ( fen - jiu ). Our results show that all investigated species deliver an important contribution to the functionality of the fermentation starter Daqu .

This work aims to evaluate the fermentability of brown rice polish for the growth of eleven Lactobacillus spp. and Pediococcus spp. strains in a single step process at a solid-state fermentation (SSF) conditions. In addition, technological and functional properties of the tested lactic acid bacteria (LAB) were assessed. The brown rice polish was a suitable substrate for the cultivation of newly isolated LAB without supplements. The acidification rate, lactic acid (LA) production ability, endo-xylanase and protease activities significantly (p

Sourdough is widely used for the preparation of traditional sourdough breads in Europe and as an important inoculum for steamed buns prepared in Asian countries, especially China. This study aims to characterize Chinese traditional sourdoughs in terms of their taxonomic compositions, physicochemical characteristics, bacterial diversity and functional features. Thirty geographically diverse sourdoughs were collected from three regions across China. High-throughput sequencing and bioinformatics were used to characterize the bacterial diversity of the sourdoughs from the different sampling sites. The results showed that the West group was significantly different from the North and South groups in the dominant genera (mainly Lactobacillus, Pediococcus and Leuconostoc) and metabolic pathways (metabolism of terpenoids and polyketides, MTP, and xenobiotics biodegradation and metabolism, XBM), whereas samples from the North and South groups were not significantly different from each other. This is the first report of the genus Clostridium in sourdough and the first report of metabolic pathways related to MTP and XBM in sourdough. This research provides a thorough description and analysis of the relationship between bacterial diversity and geographic region in sourdough.

The microbial diversity and pasting properties of three sourdoughs produced from composite gluten-free flours were investigated using 16S rRNA gene clone libraries and the Rapid Viscoanalyser. Finger millet-pearl millet (FP), Pearl millet-sorghum (PS) and Finger millet-sorghum (FS) sourdoughs were produced. Eleven aerobic bacteria and twelve lactic acid bacteria (LAB) were randomly selected from the sourdoughs. Presumptive Bacillus subtilis and Pediococcus spp. were identified in all the sourdoughs after 48 h of fermentation, while yeast was not detected in any of the products. The LAB population and pH ranged from log 7.70 CFU g−1 to log 10.52 CFU g−1 and 3.8 to 4.2 respectively. The findings showed that well-developed sourdough could be produced from these composite flours by spontaneous fermentation. Significant differences were observed in the pasting properties of all the sourdoughs. Decline in the tendency to retrograde occurred in all sourdoughs, thereby justifying the lower staling rate of final products. This study enhanced the corpus of existing knowledge on the microbial diversity of gluten-free sourdough and provided a basis for the possible application of Pediococcus spp. and Weisella spp. as a starter culture(s) in fermented products.

Phenyl lactic acid (PLA) is an antimicrobial agent with a broad antimicrobial spectrumproduced mainly by lactic acidbacteria. This study focused in the optimization of a low-cost medium to obtain biomass and PLA production by Pediococcus (Ped.) acidilacticiCRL 1753 strain and propose its use as a liquid bio-preserver in bread makingto increase the shelf life of wheat bread. First, theactivity of CRL 1753 strain against filamentous fungi and yeastswas study and a wide antifungal inhibitory spectrum was observed. Using a factorial design 29-5 an optimized and low-cost medium (10 g/L meat peptone, 5 g/L yeast extract, 10 g/L glucose, 0.0038 g/L MnSO4, 6 g/L H3PO4 and initial pH = 7.0) that could replace MRSwas obtained. A significant increase in shelf life was observed when calcium propionate (CP) and CRL 1753 strain were combined into the bread formulation. In fact, at 18 days of storage none moulds were observed when the liquid bio-preserver was added while 70 % of bread were spoilage with CP alone.In this work we report for the first time the obtaining of an optimized low-cost culture medium for biomass and PLA production by Ped. acidilacticistrain.Additionally, the ability of the bio-preserver to guarantee the microbiological safety of packed bread was demonstrated.The results obtained could be very useful as a basis to design new strategies that allow improve the PLA production at a low cost. Fil: Bustos, Ana Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina Fil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina Fil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina

The microbiota from artisanal cheeses produced in the Amazonian region is evaluated. Samples of artisanal cheeses were obtained from markets in Conceição do Araguaia and Redenção (Pará, Brazil) over rainy and dry seasons, and their biodiversity was assessed by culture-dependent and culture-independent methods. Mean counts of lactic acid bacteria (LAB) in cheeses ranged from 7.32 to 8.84 log CFU/g, for both seasons. Members of genera Lactobacillus, Lactococcus, Weissella, Enterococcus, Pediococcus, and Leuconostoc were predominant. The amplification of the 16S rRNA V6-V9 region, followed by a temporal temperature-gradient gel electrophoresis (TTGE) and sequencing of the TTGE bands revealed important differences in the microbial composition variability between samples from the two seasons and among cheese samples analyzed. TTGE showed the presence of microorganisms that are frequently found in cheese, such as L. lactis subsp. lactis, as well as other non-usual species, such as Macrococcus caseolyticus and Corynebacterium variabile. Moreover, TTGE analysis revealed the presence of microorganisms that have been isolated from other types of foods (Paralactobacillus selangorenses) along with some not usually found in foods, such as Exiguobacterium acetylicum, plus the presence of pathogenic microorganisms (Granulicatella elegans and Aerococcus sanguinicola). The present molecular approaches combined with culture-dependent methods provided a more detailed description of the microbial ecology of traditional cheeses from the Amazonian region in northern Brazil.

The bacterial communities of salami, Chinese dry-cured sausage and Chinese smoked-cured sausage were compared by high-throughput sequencing technology. The bacterial communities of Chinese dry-cured sausage and Chinese smoked-cured sausage were very different from that of salami, and the bacterial distribution was more abundant than that of salami. The highest number of operational taxonomic units (OTUs) was found in salami for the genus Staphylococcus spp., accounting for 97.45%. Accordingly, Staphylococcus spp. and, and Lactic acid bacteria (LAB), including Lactobacillus spp., Weissella spp., Pediococcus spp., and Lactococcus spp. were the main bacteria both in Chinese dry-cured sausage and Chinese smoked-cured sausage. Moreover, the salami has a microbial safety with trace Enterococcus spp. (0.03%) population. In contrast, a larger Enterococcus spp. population with relative abundance of 1.16% and 2.99% was observed in Chinese dry-cured sausage and Chinese smoked-cured sausage, respectively. Apart from Enterococcus spp., several meat spoilage bacteria, namely, Photobacterium spp., Brochothrix spp. and Pseudomonas spp. were checked in Chinese-style sausages. The results revealed that the Chinese-style sausages have a poor hygienic quality, probably due to spontaneous fermentation. This study presents that high-throughput sequencing is a useful tool to evaluate bacterial diversity and monitor microbial quality in fermented sausages.

Our aim was to identify and characterize the lactic acid bacteria (LAB) of atole agrio, a fermented Mexican maize-based beverage and to evaluate whether starters could be obtained to produce it under controlled conditions. Atole agrio fermentation process was variable with an abundant presence of Enterobacteriaceae throughout the fermentation. Based on RAPD-PCR, Weissella (29.2%), Pediococcus (24.0%), Lactococcus (17.8%) and Lactobacillus (16.4%) were the most abundant LAB genera. Out of 88 identified LAB strains, 87.5% produced folates, 71.6% degraded phytates, 38.6% produced exopolysaccharides (EPS) and 12.5% had amylolytic activity. The majority of the strains (81.8%) were resistant to at least two of the screened nine antibiotics and 11.4% to one antibiotic. Six potential starters; L. plantarum IL4l1, L. plantarum A1MM10, Lc. lactis IL5l1, Lc. lactis A1MS3, Leuc. pseudomesenteroides IL5l2 and Ped. pentosaceus S0l10, were selected for further studies. All selected strains were phytase producers, showed antimicrobial activity and had good acidification and growth properties. In addition L. plantarum IL4l1, Ped. pentosaceus S0l10 and Leuc. pseudomesenteroides IL5l2 were EPS producers and had together with Lc. lactis IL5l1 amylolytic activity. L. plantarum IL4l1, L. plantarum A1MM10 and Lc. lactis IL5l1 were folate producers., final draft, peerReviewed

This study analyzed antibiotic resistance and the occurrence of resistance genes in strains from starter and protective cultures. The largest number of obtained strains belonged to the genus Lactobacillus (n = 26; 44.9%), followed by Lactococcus (n = 17; 29.3%), Pediococcus (n = 8; 13.8%), Streptococcus (n = 4; 6.9%), Staphylococcus (n = 2; 3.4%) and Leuconostoc (n = 1; 1.7%). Among all strains, the highest Minimum Inhibitory Concentrations (MICs) were noted for tetracycline (max. >256 μg/ml), kanamycin (max. 48 μg/ml) and chloramphenicol (max. 32 μg/ml). The most common resistance genes were aph(3’)-IIIa (n = 35; 60.3%) and cat (n = 32; 55.2%). Strains derived from starter and protective cultures have the ability to horizontally transfer resistance genes in vitro and in situ. It should be noted that antibiotic resistance of bacteria from starter and protective cultures does not present an immediate risk to consumers. However, these microorganisms could become an environmental reservoir of antibiotic resistance. The obtained results indicate that antibiotic resistance in starter and protective cultures is not a critical issue, however it creates a concern that cannot be ignored.

Lactic acid bacteria as starter cultures can lead to rapid acidification for gel formation in fermented fish sausages. However, there is lack of study on the volatile flavor characteristics after starter culture addition and how they affect the microbial community on the flavor formation in fish sausages. In this work, the changes of volatile compounds and microbial community in the tilapia sausage during fermentation with Pediococcus pentosaceus were respectively studied by the headspace solid-phase microextraction gas chromatography-mass spectrometry and 16S rRNA gene high-throughput sequencing. A total of 83 volatile compounds were identified, among which 32 compounds were selected as the core volatile flavor compounds. The microbial diversity in the sausage significantly decreased as the fermentation time increased. There were 12 main microbial genera in whole fermentation stages. The anaerobes such as Pediococcus, Lactococcus, Enterobacter, and Citrobacter increased obviously after fermentation, especially for Pediococcus and Lactococcus, whose total abundance reached over 95% at the end of fermentation. The correlation network model showed that Pediococcus and Lactococcus contributed most to the volatile flavor formation, followed by Enterobacter, Citrobacter, and Photobacterium. This research provides an effective method to accelerate the volatile flavor formation and inhibit the spoilage microorganisms in the fermented tilapia sausage.

The eco-sustainability of industrial processes relies on the proper exploitation of by-products and wastes. Recently, brewers' spent grain (BSG), the main by-product of brewing, was successfully recycled through vermicomposting to produce an organic soil conditioner. However, the pre-processing step there applied (oven-drying) resulted in high costs and the suppression of microbial species beneficial for soil fertility. To overcome these limitations, a low-input pre-processing step was here applied to better exploit BSG microbiota and to make BSG suitable for vermicomposting. During 51 days of pre-treatment, the bacterial and fungal communities of BSG were monitored by denaturing gradient gel electrophoresis (DGGE). Chemical (carbon, nitrogen, ammonium, nitrate content, dissolved organic carbon) and biochemical (dehydrogenase activity) parameters were also evaluated. Mature vermicompost obtained from pre-processed BSG was characterized considering its legal requirements (e.g., absence of pathogens and mycotoxins, lack of phytotoxicity on seeds), microbiota composition, and chemical properties. Results obtained showed that throughout the pre-process, the BSG microbiota was enriched in bacterial and fungal species of significant biotechnological and agronomic potential, including lactic acid bacteria (Weissella, Pediococcus), plant growth-promoting bacteria (Bacillus, Pseudomonas, Pseudoxhantomonas), and biostimulant yeasts (Pichia fermentans, Trichoderma reesei, Beauveria bassiana). Pre-processing increased the suitability of BSG for earthworms' activity to produce high-quality mature vermicompost.

This study focused on the correlation between microbial communities and precursor substances of ethyl carbamate (EC) during soy sauce fermentation. High-throughput sequencing showed that there were ten dominant bacterial communities in soy sauce fermentation. The dominant fungal communities were Zygosaccharomyces rouxii, Candida versatilis and Candida tropicalis. Weissella, Pediococcus and Lactococcus were the dominant bacteria which had positive correlation with ethanol accumulation, while Acinetobacter, Pseudomonas and Bacillus were negatively correlated with ethanol accumulation. Fungi with the strongest positive correlation with ethanol accumulation were OTU3 and OTU110, which all belong to Zygosaccharomyces rouxii, while Ascomycotina and Aspergillus had the strongest negative correlation with ethanol accumulation. Three bacteria belong to Halobacterium, Acinetobacter and Halomonas, and two fungi belong to Aspergillus and Saccharomyces cerevisiae had the strongest positive correlation with urea accumulation, while Lactococcus and Leuconostoc, and Zygosaccharomyces rouxii had strongest negative correlation with urea accumulation. The main bacteria with positive correlation with citrulline and arginine content were Leuconostoc, Weisiella and Galactococcus, while the bacteria with negative correlation were mainly Acinetobacter, Halomonas and Halobacterium. The fungi with positive correlation with citrulline and arginine content were all mainly Zygosaccharomyces rouxii, while the fungi with negative correlation were mainly Mortierella and Apiotrichum loubieri.

This study reports the isolation of a potential probiotic lactic acid bacteria (LAB) from fermented Solanum macrocarpon food and evaluates shrimp bacterial pathogens' inhibition. The isolate was determined by identifying the inhibition zone against Vibrio parahaemolyticus with an antagonistic activity of 360 AU/mL. Molecular identification based on 16S rRNA indicated that the isolate belongs to the Pediococcus genus, named as Pediococcus pentosaceus HN10. The isolate exhibited effective inhibitory ability against various pathogenic including antibiotic-resistant Vibrio spp., Escherichia coli ATCC 85922 and Staphylococcus aureus ATCC 25023. P. pentosaceus HN10 showed potential probiotic properties such as strong salt tolerance, low pH and bile salts resistance, autoaggregation and coaggregation activities. P. pentosaceus HN10 was negative for β-hemolytic and amino acid decarboxylase. Antibiotic resistance assay showed that this strain was sensitive to ampicillin and chloramphenicol. P. pentosaceus HN10 expressed strongly antioxidant activity. In vivo challenge to V. parahaemolyticus in shrimp model indicated P. pentosaceus HN10 enhanced survival rate, weight gain as well as reduced the number of Vibrio in shrimp intestine tract. Overall, this study suggests that P. pentosaceus HN10 could be applied as a supplementation feed for shrimp to minimize pathogenic bacteria's negative effect.

Sichuan industrial paocai and traditional home-made paocai have different aroma profiles due to different manufacturing techniques, but detailed information about the aroma profiles and aroma-producing microorganism of Sichuan industrial paocai remain largely elusive. For this reason, we established and validated an external standard method of headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC–MS) combined with gas chromatography–olfactometry (GC-O) for identification and accurate quantitation of aroma-active compounds in Sichuan industrial paocai. This method was combined with 16S rRNA amplicon sequencing to comprehensively analyze the aroma and bacteria profiles of Sichuan industrial paocai. A total of 121 volatile compounds were identified, among which 36 odorants were identified as aroma-active compounds with aroma intensities (AIs) ranging from 0.67 to 5.00 by GC-O. The types of aroma-active compounds in Sichuan industrial paocai were variety-specific to some extent, but the aroma-active compounds shared by different varieties of Sichuan industrial paocai (i.e., skeleton aroma-active compounds) were phenylethyl alcohol, acetic acid, butanoic acid, 2-methylbutanoic acid, ethyl hexanoate, 4-ethylphenol and 4-ethylguaiacol. Moreover, 17 key aroma-active compounds of AI > 1 in radish paocai were quantitated by external standard method, and their odor activity values (OAVs) were calculated based on the odor thresholds. Further, 12 aroma-active compounds with OAV ≥ 1 in one of the radish paocai were selected to construct the recombination model, which revealed good agreement with the original sample. Furthermore, Lactobacillus, Pediococcus, Pseudomonas and Sphingomonas were the dominant bacteria in Sichuan industrial paocai. Correlation analysis between 16 dominant bacteria and 36 aroma-active compounds showed that Pediococcus, Arcobacter and Lactobacillus could be the core aroma-producing bacteria of Sichuan industrial paocai.

The present work is the first report on spontaneous fermentation of curly kale and characteristics of autochthonous lactic acid bacteria (LAB). Our results indicate that curly kale fermentation is the new possibility of the technological use of this vegetable. Bacteria representing ten different species were isolated from three phases of curly kale fermentation and identified by MALDI-TOF mass spectrometry and 16S rRNA gene sequencing. Among them, four species were identified as Lactobacillus spp. (Lb. plantarum 332, Lb. paraplantarum G2114, Lb. brevis R413, Lb. curvatus 154), two as Weissella spp. (W. hellenica 152, W. cibaria G44), two as Pediococcus spp. (P. pentosaceus 45AN, P. acidilactici 2211), one as Leuconostoc mesenteroides 153, and one as Lactococcus lactis 37BN. The functional properties of isolates, i.e. acid, NaCl and bile salt tolerance, enzyme activities, adhesion to hydrocarbons, and antibiotic resistance, were examined. Among the tested strains, Lb. plantarum 332, Lb. paraplantarum G2114, P. pentosaceus 2211, and Lb. brevis R413 exhibited the best hydrophobicity value and high tolerance to bile salts, NaCl, and low pH.

This study aimed to separate the effects of chemical composition and epiphytic microflora on the fermentation quality and bacterial community of Napier grass silage. Napier grass was harvested in two vegetative stages (Early, EG; Late, LG) with 24 or 28% dry matter, cut into theoretical lengths of 2–3 cm, and ensiled in bag-type silos containing 450 g fresh matter for 30 d. A 2 × 2 factorial arrangement of treatments (2 chemical composition × 2 epiphytic microbiota) in a completely randomized design were as follows: EG epiphytic microbiota + gamma-ray irradiated EG (EMEG), LG epiphytic microbiota + gamma-ray irradiated EG (LMEG), EG epiphytic microbiota + gamma-ray irradiated LG (EMLG), and LG epiphytic microbiota + gamma-ray irradiated LG (LMLG). Triplicates per treatment were sampled after 30 d of ensiling for fermentation quality and bacterial community analyses. The maturity of Napier grass had a great impact on its chemical composition and epiphytic microflora at harvest. Silages made from irradiated EG (EMEG and LMEG) had higher lactic acid concentration and lactic:acetic acid ratio, and lower pH value and ammonia nitrogen (NH3-N) concentration than the silages made from irradiated LG (EMLG and LMLG). Species differential analyses showed that the chemical composition variation significantly affected the relative abundance of Lactobacillus, Lactococcus, Enterobacter, Serratia, unclassified Lactobacillales, Leuconostoc and Pediococcus in EMEG and EMLG silages. While there was no effect of epiphytic microbial variation on the relative abundance of bacterial genera in EMLG and LMLG silages. These results manifested that, in this study, chemical composition rather than epiphytic microflora affected the succession of bacterial community in Napier grass silages, thereby affecting the final fermentation quality.

To investigate the general fermentation features of doenjang, a traditional Korean fermented soybean paste, eleven batches of doenjang were prepared. The bacterial and fungal communities and the metabolites such as free sugars, organic acids, amino acids, and volatile compounds were analyzed during fermentation. Tetragenococcus, Aspergillus, and Debaryomyces were the most common microbes; galactose, fructose, and glucose were the major sugars; and lactate and acetate were the major organic acids. Spearman correlation analyses showed that the quantity of meju was correlated with only Pediococcus and Halomonas abundance, while solar salt concentration was correlated with the relative abundance of many microbial taxa and the amount of glycerol and total volatile compounds. The abundance of heterolactic acid bacteria, such as Tetragenococcus, Pediococcus, Weissella, and Enterococcus, was positively correlated with the levels of lactate, acetate, and ethanol, suggesting that heterolactic acid fermentation may be a major metabolism pathway during the fermentation of doenjang. The abundance of Weissella, Hyphopichia, and Wickerhamomyces was positively correlated with ethyl acetate levels, whereas the abundance of Staphylococcus and Bacillus was positively correlated with the concentration of major volatile compounds, 3-methylbutanoic acid and tetramethylpyrazine, respectively, suggesting that they may play important roles in the production of flavor compounds during fermentation.

‘Bask in daytime and dewed at night’ technique is traditionally used in doubanjiang fermentation, however, the underlying mechanism behind this technique is still unrevealed. This study aimed to elaborate the roles of three key indexes in this technique, that are air, sunlight, and mash turnover, on doubanjiang quality through the design of doubanjiang fermentation. The results showed that the exposure to air or sunlight was beneficial for doubanjiang to yield reddish-brown luster color, less acidity and balanced flavor. On the contrary, blocking of air and sunlight could accumulate higher acidity (4.75 ± 0.01 g/100gdw), amino nitrogen (2.08 ± 0.07 g/100gdw), alcohols (36.9 g/kg) and esters (26.9 g/kg). Regular mash turnover was mainly involved in making different mash layers exposure to air or sunlight equally through homogenizing mash layers. Different conditions also have been suggested to affect the microbiota dynamics by amplicon sequencing and RT-qPCR. Based on RDA analysis, Pediococcus, Meyerozyma, Bacillus and Zygosaccharomyces were predicted to be related to the changes of physicochemical properties or volatile compounds in different conditions, and their function was validated by simulated fermentation. This study would unravel the underlying scientific meaning of ‘bask in daytime and dewed at night’ technique in doubanjiang fermentation.

In the present study, LAB (Lactic acid bacteria) were isolated and identified from Kradi cheese. Results revealed presence of five dominant LAB viz. Lb. curvatus, Lb. sake, Lb. planatrum, Pediococcus pentosaceous and Enterococcus faecium. Among these probiotic strains, Lb. planatrum showed highest hydrophobicity and antimicrobial activity against different pathogenic strains. The cheese sample was further subjected to simulated gastrointestinal digestion (SGID) to obtain water-soluble peptide extract (WSPE). Bioactivity assays of WSPE, including, ABTS radical inhibition, reducing power, lipid peroxidation inhibition, α-glucosidase inhibition and α-amylase inhibition increased significantly from 12.03 to 58.89%, 14.85–55.72%, 14.67–52.43%, 15.55–57.65%, 17.88 %-59.33%, respectively from 0 to 420 min of digestion. Anti-cancer and anti-hypertensive activity of WSPE increased significantly from 13.44 to 69.39% and 19.75–71.23% upon digestion in simulated gastrointestinal juice (SGIJ). The overall results suggest that bioactivity of sample enhanced upon digestion validating Kradi cheese as a potential source of bioactive peptides and probiotics and therefore, may be categorized as a functional food.

Wheat Qu contains various microorganisms and is the fermentation starter for rice wine. The impact of geographic location on the volatile compounds and microbial communities in wheat Qu remains unknown. This study demonstrated significant differences in the volatile compound profiles of wheat Qu from different regions of China. Phenylethyl alcohol, hexadecanoic acid methyl ester, 9-octadecenoic acid methyl ester, and 2-octanone were the main volatile compounds detected. The bacterial and fungal communities in wheat Qu also differed significantly according to geographic location with both communities explaining the variation in volatile compounds (bacteria making the greater contribution). The bacterial community was dominated by Pediococcus, Weissella, and Lactobacillus while the fungal community was dominated by Saccharomycopsis and Rhizopus. Bacteria exhibited more significant associations with volatile compounds than fungi did. Prediction of metabolic function demonstrated significantly different profiles for the bacterial communities from different regions. These data showed that geographic location considerably affects the composition of volatile compounds and microbial communities in wheat Qu, with the bacterial community being the main contributor to variation of volatile compounds.

Bacterial community composition influences the formation of flavourful substances in fermented foods. However, the bacterial structure of fermented vegetables from different origins has scarcely been reported. Here, 10 different fermented vegetables of Chinese origin were collected to explore the bacterial community diversity using 16S rDNA sequencing. Of these samples, the number of identified operational taxonomic units (OTUs) ranged from 107 to 290, which could be categorized into 12 phyla, 21 classes, 52 orders, 97 families, 223 genera and 348 species. Firmicutes and Proteobacteria were the top two dominant phyla with a relative abundance of 88.2–99.3% of the total OTUs. Meanwhile, Lactobacillus alimentarius , L. versmoldensis , Bacillus and unclassified Weissella spp. were detected as the predominant Firmicutes bacteria, while Chromohalobacter japonicus , Halomonas jeotgali , Pediococcus and unclassified Vibrio spp. were the most abundant proteus bacteria. Hierarchical cluster and principal component analysis indicated that the 10 samples could be grouped into three groups, with the main two components explaining 49.1 and 28.6% of the total variance. These results indicated a high level of diversity in the bacterial community structure in traditional fermented vegetables and demonstrated the possible influences of manufacturing location and conditions, and/or the type of raw material, on bacterial diversity.

The Enterococcus faecium strain MXVK29, isolated from fermented sausages, produces a bacteriocin with a molecular mass of 3.5 kDa that belongs to the class of enterocins II.1, according to the terminal amino acid sequence, and has been identified as enterocin A. This bacteriocin is active against selected strains of Listeria, Staphylococcus, Pediococcus, and Enterococcus. In this study, we identified the genes adjacent to the structural gene for this bacteriocin, such as the immunity gene (entI) and the inducer gene (entF). Accessory genes for this bacteriocin, such as entK, entR, and entT, were identified as well, in addition to the orf2 and orf3, showing a high identity with class IIb peptides bacteriocins. The orf2 shows the consensus motif GxxxG, similar to those shown by bacteriocins such as PlnNC8α, EntCα, and Ent1071A, whereas orf3 shows a consensus motif SxxxS similar to that present in PlnNC8β (AxxxA). PlnNC8 is expressed only in bacterial cocultures, so there is the possibility that the expression of this two-peptide bacteriocin can be induced by a similar mechanism. So far, only the expression of enterocin A has been found in this strain; however, the presence of the genes ent29α and ent29β opens the possibility for further research on its induction, functionality, and origin. Although there are reports on this type of bacteriocin (EntX, EntC, and Ent1071) in other strains of E. faecium, no report exists yet on an Enterococcus strain producing two different classes of bacteriocin.

Serofluid dish is a traditional Chinese salt-free fermented vegetable. In this study, the microbial succession and metabolite changes during celery serofluid dish fermentation were investigated using high-throughput sequencing and GC-TOFMS methods. The results showed that the leading genera of bacteria were Lactobacillus and Pediococcus in eight serofluid samples; Debaryomyces was the dominant fungal genus followed by Saccharomyces . A total of 182 metabolites were identified, mainly organic acids and amino acids. Correlation analysis revealed important links between microbial populations and metabolites. These results lend new insights into the fermentation process and provide a theoretical basis for the economical production of safe, high-quality serofluid dish.

High level aminoglycoside resistance (HLAR) in the lactic acid bacteria (LAB) derived from food animals is detrimental. The aim of this study was to investigate the localization and conjugal transfer of aminoglycoside resistance genes, aac(6')Ie-aph(2″)Ia and aph(3')IIIa in different Enterococcus species. The cross resistance patterns in Enterococcus faecalis MCC3063 to clinically important aminoglycosides by real time PCR were also studied. Southern hybridization experiments revealed the presence of aac(6')Ie-aph(2″)Ia and aph(3')IIIa genes conferring HLAR in high molecular weight plasmids except in Lactobacillus plantarum. The plasmid encoded bifunctional aac(6')Ie-aph(2″)Ia gene was transferable from Enterococcus avium (n = 2), E. cecorum (n = 1), E. faecalis (n = 1) and Pediococcus lolii (n = 1) species into the recipient strain; E. faecalis JH2-2 by filter mating experiments thus indicating the possible risks of gene transfer into pathogenic strains. Molecular analysis of cross resistance patterns in native isolate of E. faecalis MCC3063 carrying aac(6')Ie-aph(2″)Ia and aph(3')IIIa gene was displayed by quantification of the mRNA levels in this study. For this, the culture was induced with increasing concentrations of gentamicin, kanamycin and streptomycin (2048, 4096, 8192, 16384 μg/mL) individually. The increasing concentrations of gentamicin and kanamycin induced the expression of the aac(6')Ie-aph(2″)Ia and aph(3')IIIa resistance genes, respectively. Interestingly, it was observed that induction with streptomycin triggered a significant fold increase in the expression of the aph(3')IIIa gene which otherwise was not known to modify the aminoglycoside. This is noteworthy as streptomycin was found to confer cross resistance to structurally unrelated kanamycin. Also, expression of the aph(3')IIIa gene when induced with streptomycin, revealed that bacteria harbouring this gene will be able to overcome streptomycin bactericidal action at specific concentrations. HLAR in E. faecalis MCC3063 may be due to the combined expression of both the aac(6')Ie-aph(2″)Ia and aph(3')IIIa genes which could be therapeutically challenging. A combined expression of both the genes in E. faecalis MCC3063 may yield HLAR which could be therapeutically challenging. The study highlights the significant alterations in the mRNA expression levels of aac(6')Ie-aph(2″)Ia and aph(3')IIIa in resistant pathogens, upon exposure to clinically vital aminoglycosides.

The present study was carried out to enhance shelf life of raw buffalo milk by the use of pediocin PA-1 containing fermented cheese whey (PCFCW) as bio-preservative. Ten distinct genera of milk microbes could be identified as Streptococcus, Enterococcus, Salmonella, Campylobacter, Lactobacillus, Enterobacter, E. coli, Shigella, Candida and Aspergillus. For the production of PCFCW, supplemented cheese whey medium was fermented with Pediococcus pentosaceous NCDC 273 for 24 h. Partially purified PCFCW was prepared using ammonium sulphate precipitation followed by membrane ultrafiltration with 10 kDa and 3 kDa membrane (Millipore) respectively. The fraction between 10 and 3 kDa was used as bio-preservative. This bio-preservative was found to contain pediocin PA-1 at the level of 2.04 × 105 AU/ml. In view of the wide antibacterial spectrum of pediocin, the PCFCW formulation was added at 1%, 5%, and 10% (v/v) concentrations to raw buffalo milk to reduce total microbial load. A significant decrease (p˂0.05) was observed in total viable count on TGYEA, Staphylococcus aureus count on BPA, and lactic acid bacterial count on MRSA. However, the reduction in coliform count on VRBA and yeast-mould count on PDA was non-significant (p˂0.05). Therefore, it can be concluded that partially purified PCFCW was effective in reducing total microbial load in raw buffalo milk.

Background In this study, the fermentation of ginseng seeds was hypothesized to produce useful physiologically-active substances, similar to that observed for fermented ginseng root. Ginseng seed was fermented using Bacillus, Pediococcus, and Lactobacillus strains to extract ginseng seed oil, and the extraction yield, color, and quantity of phenolic compounds, fatty acids, and phytosterol were then analyzed. Methods The ginseng seed was fermented inoculating 1% of each strain on sterilized ginseng seeds and incubating the seeds at 30°C for 24 h. Oil was extracted from the fermented ginseng seeds using compression extraction, solvent extraction, and supercritical fluid extraction. Results and Conclusion The color of the fermented ginseng seed oil did not differ greatly according to the fermentation or extraction method. The highest phenolic compound content recovered with the use of supercritical fluid extraction combined with fermentation using the Bacillus subtilis Korea Food Research Institute (KFRI) 1127 strain. The fatty acid composition did not differ greatly according to fermentation strain and extraction method. The phytosterol content of ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method was highest at 983.58 mg/100 g. Therefore, our results suggested that the ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method can yield a higher content of bioactive ingredients, such as phenolics, and phytosterols, without impacting the color or fatty acid composition of the product.

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.

The taxonomic differentiation among lactic acid bacteria (LAB) using only phenotypic methods is inadequate. In the past, several phenotypic techniques have been applied in identification of different species of LAB from Nigerian indigenous fermented foods. In this study, two less-expensive and rapid molecular techniques were employed in the identification and differentiation of LAB species isolated from some Nigerian fermented foods: gari (cassava mash), fufu (cassava dough) and ogi (maize gruel) to avoid the common errors that are synonymous with the use of conventional methods. The size of the amplified products for the LAB species using universal primers fD1 and rD1 was about 1500 bp. The differentiation of the three predominant LAB, Lactobacillus plantarum , Pediococcus pentosaceus and Weissella confusa to species level was performed by intergenic transcribed spacer (ITS-PCR) and amplified ribosomal DNA restriction analysis (ARDRA) using three restriction endonucleases: Hinf I, Hae III and Rsa I. In summary, the study demonstrated that the ARDRA and ITS-PCR analysis are simple, fast and efficient methods that can be used for the routine identification and rapid differentiation of LAB species which are often regularly used as probiotics, starter culture and biopreservative in fermented foods consumed since they are generally regarded as safe (GRAS).

Grapevine shoots, known to be a source of bioactive stilbenes, are considered one of the most important and abundant waste products from the vineyard. The objective of this study was to obtain a pure stilbene extract from grapevine shoots and test its properties, mainly antimicrobial ones, as a preservative in wine. A new extract with a purity of 99% in stilbenes was obtained by centrifugal partition chromatography. The extract was characterized by HPLC-MS, the main compounds being E-e-viniferin (70%) and E-resveratrol (18%). The stability conditions for the extract solution were low temperature (4 °C) and darkness for a maximum of 21 days. Data regarding to the stability of E-ϵ-viniferin, ω-viniferin and r-viniferin are reported first. The antimicrobial activity of the extract was higher against yeast (Brettanomyces bruxellensis, Zygosaccharomyces bailli, Haseniaspora uvarum, Candida zemplinina) than against bacteria (Lactobacillus hilgardii, Oenococcus oeni, Pediococcus pentasaceus). The best antimicrobial activity was found on Brettanomyces bruxellensis and Zygossaccharomyces bailli. The aromatic characterization of the extract allows us to establish that it does not affect the sensory properties of wine, and thus wine quality is not compromised with the addition of the extract. All of the above allow us to propose ST99 as a promising alternative to SO2 in wines, including rose and white wines.

Soaking is a crucial process in adjusting initial fermentation acidity and achieving desired flavor quality of rice wines. Effects of soaking time on physicochemical characteristic of rice, flavor profiles, microbial community and sensory characteristic of Huangjiu were investigated. Soaking caused significantly changes in amylopectin content, and rice with high amylopectin content was conducive to produce esters and aldehydes during Hungjiu brewing. High-throughput sequencing showed that bacteria types were more abundant than fungi during brewing, suggesting that bacterial community might be primarily responsible for Huangjiu flavor. Differential analysis revealed that Weissella and Enterobacter contributed greatly to the accumulation of alcohols, esters and aldehydes during Huangjiu brewing, while Clostridium, Acinetobacter, Cyanobacteria, Zymomonas and Exiguobacterium were responsible for the rancidity. Based on spearman's correlation analysis, Lactococcus, Weissella, Pediococcus, Lactobacillus and Staphylococcus were the key microbial genera responsible for the flavor characteristic of Huangjiu. While favorable soaking caused an increased intensity in alcohol-aroma, full body and continuation of resultant Huangjiu, insufficient soaking led to a higher intensity of bitter taste. Summarily, soaking acidity ranged from 2 to 3 g/L was beneficial for preventing rancidity and improving the production of flavor compounds in Huangjiu.

Zha-chili is a traditional Chinese fermented food with special flavor, which is often used as an appetizer in condiments and an important energy source. The final quality of zha-chili is closely related to its microbial community structure. However, the differences of bacterial diversity in zha-chili from different regions and how bacterial species affect zha-chili fermentation process and flavor quality have not been reported. In this study, the bacterial diversity and flavor quality of zha-chili samples from different regions were analyzed using Illumina Miseq high-throughput sequencing, electronic nose and electronic tongue technology. Twenty-three bacterial phyla and 665 bacterial genera were identified in all zha-chili samples. Firmicutes, Proteobacteria and Actinobacteria were the dominant bacterial phyla in zha-chili samples, while Lactobacillus, Pseudomonas, Pediococcus, Weissella and Staphylococcus were the dominant bacterial genera. The bacterial community structure of zha-chili samples from different regions was significantly diverse (p 0.05). The flavor of zha-chili samples also varied in different regions, and the discrepancy of taste was much greater than that of aroma. Moreover, there were significant correlations (p 0.05) between 6 dominant bacterial genera and 8 flavor indicators (3 aroma indicators, 5 taste indicators). In addition, the results of microbiome phenotypes prediction by BugBase and bacterial functional potential prediction using PICRUSt showed that eight out of nine predicted phenotypic functions of zha-chili samples from different regions were significantly different (p 0.05), bacterial metabolism was vigorous in the zha-chili samples, and Lactobacillus was the dominant bacterial genus involved in metabolism during fermentation.

It has been unclear how long Chinese Baijiu Daqu's storage period would be appropriate. To this end, physicochemical and enzymatic tests on the samples of two kinds of Strong-flavor Daqu during the storage period of 7 months were performed. Meanwhile, the dynamics of microbial communities during storage were also explored using high-throughput sequencing. The results showed that both the physicochemical properties and the enzymatic indices have altered in different extents with the extension of storage period of two kinds of Daqu. A total of 21 dominant microbial taxa at the genus level were found in two Daqu. Among them, Weissella, Lactobacillus, Pediococcus, Bacillus and Acetobacter were the common prokaryotic microorganisms in two Daqu. Pichia and Thermoascus were the two major eukaryotes in two Daqu. Overall, the T-Daqu presented a more stable prokaryotic succession than that of M-Daqu, while the eukaryotic succession seemed opposite. The variation trends of the physiochemical and enzymatic indices of the two Daqu marked the effective time of storage period which are appropriately 60–210 days for M-Daqu and 60–180 days for T-Daqu.

The succession of microbial community significantly affect the flavor formation of traditional fermented foods and beverages. Chinese liquor (Baijiu) fermentation is a typical spontaneous solid-state fermentation process driven by natural microbiota. The type of process used to make liquor-craft or industrial-alters the operational environment and the aromatic qualities of the product contributed by various microbial consortia. But differences in microbial community assembly and temporal succession are often overlooked. In this study, we investigated bacterial community dynamics, substrate consumption, and metabolite production during both craft and industrial liquor-making processes (CLP and ILP, respectively). We found that the compositions of bacterial communities were different, even though no significant difference (p > 0.05) was observed in bacterial species between CLP and ILP at the beginning of fermentation. During ILP, glucose was used more rapidly by microflora, leading in turn to a higher ethanol production rate during the early stage of fermentation. The higher rate of ethanol production in ILP shortened the lifetime of bacteria such as Weissella, Pediococcus, Leuconostoc, and Bacillus during the early stage of fermentation. Lactobacillus sp. became dominant earlier in ILP than in CLP. Finally, the change in bacterial community dynamics led to changes in aroma compounds. Using CLP and ILP as a model system, our results illustrate the dynamic nature of Baijiu fermentations and microbial succession patterns therein. This can be applied to optimize the fermentation processes and flavors attributes of this and other fermented foods.

As a widely used Asian starter culture, the quality of daqu can significantly affect the organoleptic characteristics of the final products, yet the microbial metabolic network involved in flavor development remains unclear. This study aims to investigate that network based on the dynamics of physicochemical properties, microbial community, and volatile compounds in medium-temperature daqu (MT-daqu) during spontaneous fermentation. Analyses using the metagenomic data set facilitated the gene repertoire overview of this ecosystem, indicating that Lactobacillales (mainly Weissella, Lactobacillus, and Pediococcus), Mucorales (mainly Lichtheimia), and Eurotiales (mainly Aspergillus, Rasamsonia and Byssochlamys) were the potential predominant populations successively responsible for the production of lytic enzymes and flavor precursors/compounds in MT-daqu. Flavor-relevant pathways were found to exist in multiple species, but only bacteria showed the potential to participate in butane-2,3-diol (e.g. Weissella, Lactobacillus, and Staphylococcus) and butanoate (Thermoactinomyces) metabolism, and only fungi were potentially involved in biosynthesis of guaiacol (Byssochlamys) and 4-vinylguaiacol (Aspergillus). Furthermore, a combined analysis revealed that the acidic thermal environment present in early phases was mainly due to the catabolic activities of Lactobacillales and Lichtheimia, which could contribute to the effective self-domestication of microbiota. The study helps elucidate the different metabolic roles of microorganisms and disclose the formation mechanism of daqu's partial functions, namely providing various aromatic substances/precursors and enzymes.

The effect of Pediococcus acidilactici and Lactobacillus sakei strains on biogenic amines (BAs) formation during submerged and solid state fermentation of Lupinus luteus and Lupinus angustifolius was analysed. The composition of lupin seeds was evaluated and the influence of fermentation on free amino acid (FAA) profile was investigated. The highest protein and carbohydrate contents were found in L. luteus var. ‘Vilciai’, the highest carbohydrate contents – in L. angustifolius hybrid lines No. 1701 and No. 1800, and fat – in L. angustifolius hybrid lines No. 1700, No. 1703 and No. 1734. The interaction between the fermentation method, the bacterial strains used and lupin varieties had significant effects on the acidity parameters and lactic acid bacteria count in fermented samples. There was a significant effect ( P

The lactic acid bacteria (LAB) microbiota of quinoa grains (QG) and spontaneous sourdough (QSS) was evaluated. Different strains of Lactobacillus (L.) plantarum (7), L. rhamnosus (5), L. sakei (1), Pediococcus (Ped.) pentosaceus (9), Leuconostoc (Leuc.) mesenteroides (1), Enterococcus (E.) casseliflavus (2), E. mundtii (3), E. hirae (1), E. gallinarum (12), Enterococcus sp. (1), and E. hermanniensis (2) were isolated, identified and characterized. Only four strains isolated from QSS and eight strains isolated from QG showed amylolytic activity. L. plantarum CRL 1973 and CRL 1970, L. rhamnosus CRL 1972 and L. sakei CRL 1978 produced elevated concentrations of folate with strain CRL 1973 producing the highest concentration (143 ± 6 ng/ml). L. rhamnosus, isolated from QSS, was the LAB species that produced the most elevated concentrations of total riboflavin (> 270 ng/ml) with strain CRL 1963 producing the highest amounts (360 ± 10 ng/ml). Phytase activity, evaluated in forty-four LAB strains from quinoa, was predominantly detected in L. rhamnosus and Enterococci strains with the highest activities observed in E. mundtii CRL 2007 (957 ± 25 U/ml) followed by E. casseliflavus CRL 1988 (684 ± 38 U/ml), Leuc. mesenteroides CRL 2012 (617 ± 38 U/ml) and L. rhamnosus CRL 1983 (606 ± 79 U/ml). In conclusion, this study shows that a diverse LAB microbiota is present in quinoa with important properties; these microorganisms could be used as potential starter cultures to increase the nutritional and functional properties of Andean grains based foods. Fil: Carrizo, Silvana Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Montes de Oca, Cecilia Estefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Laiño, Jonathan Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Suárez, Nadia Elina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Vignolo, Graciela Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Rollan, Graciela Celestina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina. Universidad del Norte Santo Tomás de Aquino; Argentina

Various microbial communities play a role in generating the distinctive sensory characteristics of the traditional Korean soybean paste, doenjang. The objective of this study was to investigate the relationship between sensory characteristics and microbial communities in traditional doenjang. The results of the descriptive analysis revealed that some traditional doenjang (T1-T11) exhibited distinctive characteristics, such as fish sauce flavor, meju, bitterness, sourness, and saltiness, whereas the modified samples (M1-M3) demonstrated sweetness, umami, and an alcohol odor. According to the metagenomic analysis based on 16S rRNA gene sequencing, the phylum Firmicutes was the dominant bacterium in most doenjang. At the genus level, lactic acid bacteria (LAB) were frequently found in most doenjang. Among these LAB, the major genera of bacteria were Tetragenococcus in M2 (60.30%), T3 (91.20%), T8 (48.60%), and T9 (60.90%); Enterococcus in T1 (29.40%), T4 (34.10%), and T10 (50.50%); Leuconostoc in T7 (89.10%); and Lactobacillus in T9 (38.3%). The most frequently occurring non-LAB was Bacillus in M3 (50.10%), T5 (46.50%), and T6 (20.50%), and M1 and T2 contained Staphylococcus and Ochrobactrum as their major non-LAB, respectively. The results of a correlation analysis between the sensory attributes from the descriptive analysis and the microbial communities from 454 pyrosequencing provided an overview for the relationship between sensory characteristics and microbial communities. Ochrobactrum, Stenotrophomonas, Rhodobacteraceae, Proteus, and Luteimonas were found in samples that had a strong fish sauce characteristic. The presence of LAB-Tetragenococcus, Enterococcus, Pediococcus, Carnobacterium, and Weissella-was related to sourness. Enterococcus and Enterobacter were found in samples with a matured flavor and a soft mouthfeel, respectively. The overall results of the study demonstrate that microbial communities found in doenjang were closely related to distinct sensory attributes.

The main goal of this work was to investigate the bacterial flora present in the traditional fermentation starters using matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) mass spectrometry fingerprinting combined with 16S rRNA gene sequencing and species-specific PCRs. A total of 1314 bacterial strains were obtained from ten kinds of representative wine fermentation starters (5 Hong Qu and 5 Yao Qu) and classified by MALDI-TOF mass spectrometry. Sixteen different bacterial species belonging to six different genera (Bacillus, Staphylococcus, Leuconostoc, Pediococcus, Lactobacillus and Lactococcus) were identified with high accuracy by comparing them with generated spectra of MALDI Biotyper database. Comparison of 16S rRNA gene phylogeny and MALDI-TOF mass spectrometry analysis showed that MALDI-TOF mass spectrometry fingerprinting was a good complementary approach to 16S rRNA sequencing and even a more powerful tool in the accurate differentiation and classification of Bacillus species, especially for differentiating between Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus methylotrophicus. MALDI-TOF mass spectrometry was also found to provide valuable information at species levels for the genus of Lactobacillus. The identification revealed that most strains isolated from traditional fermentation starters were B. amyloliquefaciens (31.81%), followed by Bacillus megaterium (16.89%), Lc. lactis subsp. lactis (8.60%) and B. subtilis (8.14%). In the culture-dependent quantitative analysis, 69.01% of the detected isolates were Bacillus species, and 30.44% of the detected isolates belonged to the class of lactic acid bacteria (LAB), including Leu. mesenteroides, Pediococcus pentosaceus, Lactobacillus plantarum, Lactobacillus paracasei, Lactobacillus brevis, Pediococcus acidilactici, Lactobacillus coryniformis and Lc. lactis subsp. lactis. This study provides detailed evaluation of bacterial communities in the traditional fermentation starters for Hong Qu glutinous rice wine using a fast and cost-effective technique—MALDI-TOF mass spectrometry fingerprinting. Information provided by this study is fundamental and useful to develop effective strategies for the selection of beneficial bacterial strains and improve of quality of Hong Qu glutinous rice wine.

Lactic Acid Bacteria (LAB) were isolated from cereals and seeds from Argentinean markets. Colonies representing different morphological appearances were isolated and differentiated based on phenotypic characteristics. Fifty strains were identified by 16S rRNA gene sequencing analysis obtaining LAB from genera Enterococcus, Lactobacillus and Pediococcus. Technological and nutritional characteristics (acidifying capacity, antimicrobial production, proteolytic activity, folate production) were analyzed. Lactobacillus pentosus ES124 and Lactobacillus plantarum ES137 presented high production of folate (61 and 57 ng/mL, respectively) as did Enterococcus mundtii ES63 which reached a total folate production of 70 ng/mL. Six LAB strains produced bacteriocin-like inhibitory substances (BLIS) with antilisterial activity. Eight strains were selected for use as sourdough starters and in situ applications based on their important technological properties. Fil: Salvucci, Emiliano Jesus. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Cs.químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina Fil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina Fil: Perez, Gabriela Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Cs.químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina

Silage fermentation improves when alfalfa is ensiled along with whole-plant corn, yet so far the impact of their mixing ratios on individual bacteria during fermentation is weakly described. The objective of this work was to explore the effect of combining alfalfa with whole-plant corn in different ratios on silage bacterial community and fermentation profile over the entire ensiling process. The alfalfa at the early bloom stage and whole-plant corn at around the 1/3 milk line stage were freshly chopped and blended at proportions of 1:0 (served as Control), 0.8:0.2 (Mix 1), 0.6:0.4 (Mix 2) and 0:1 on a fresh matter basis. Each treatment was prepared in triplicate and ensiled in plastic bag silos for 0, 3, 7, 14 and 35 days. The fermentation coefficient of fresh matter used to asses a forage ensilability linearly increased, with more corn in the mixture. During the first 3 days of fermentation, the greatest pH drop occurred in all silages. Seven days later, the silage pH in Mix 1, Mix 2 and corn further decreased, and alfalfa silage pH slightly increased, however. After 35 days of ensiling, alfalfa silage was poorly fermented, shown by a high level of pH (4.69), acetic acid (35.7 g/kg dry matter), propionic acid (29.0 g/kg dry matter), n-butyric acid (12.1 g/kg dry matter) and ammonia nitrogen (108 g/kg total nitrogen). Silage fermentation was significantly improved with corn percentage increasing from 20 % to 100 %. In the early stage of fermentation, Lactobacillus and Pediococcus relative abundance noticeably increased in alfalfa, Mix 1 and Mix 2 silages, whereas Leuconostoc abundance was noticeably enriched and outnumbered Lactobacillus and Pediococcus in corn silage. During 7–35 days of ensiling, the bacterial community structure in all silages comparatively stayed stable. Besides, Lactobacillus abundance increased while Pediococcus and Weissella richness decreased with more corn, at each period above. The bacterial community composition of all fresh materials was similar at the genus level, consisting mainly of Weissella, Leuconostoc, Pantoea, Enterobacter, Pseudomonas and Rosenbergiella. However, the development of Lactobacillus, Pediococcus and Leuconostoc species in alfalfa, Mix 1 and Mix 2 silages in the early stage of fermentation was different from corn silage. Subsequently, the bacterial community structure in all silages relatively stayed stable. Overall silage fermentation quality was better when alfalfa was ensiled in a mixture with at least 20 % whole-plant corn on a fresh matter basis.