Pediococcus spp.-mediated competition interaction within Daqu microbiota determines the temperature formation and metabolic profiles.

Fermented microbiota is critical to the formation of microenvironment and metabolic profiles in spontaneous fermentation. Microorganisms generate a diverse array of metabolites concurrent with the release of heat energy. In the case of Daqu fermentation, the peak temperature exceeded 60°C, forming a typical high-temperature fermentation system known as high-temperature Daqu. However, microorganisms that cause the quality variation in Daqu and how they affect the functional microbiota and microenvironment in the fermentation process are not yet clear. This study adopted high-throughput sequencing and monitored the dynamic fluctuations of metabolites and environmental factors to identify the pivotal microorganism responsible for the alterations in interaction patterns of functional keystone taxa and quality decline in the fermentation system of different operational areas during the in situ fermentation process that had been mainly attributed to operational taxonomic unit (OTU)_22 (Pediococcus acidilactici). Additionally, we used isothermal microcalorimetry, plate inhibition experiments, and in vitro simulation fermentation experiments to explore the impact of Pediococcus spp. on heat generation, microorganisms, and metabolite profiles. Results showed the heat peak generated by Pediococcus spp. was significantly lower than that of Bacillus spp., filamentous fungi, and yeast. In addition, the preferential growth of P. acidilactici strain AA3 would obviously affect other strains to colonize through competition, and its metabolites made a significant impact on filamentous fungi. The addition of P. acidilactici strain AA3 in simulated fermentation would cause the loss of pyrazines and acids in metabolites. These evidences showed that the overgrowth of Pediococcus spp. greatly influenced the formation of high temperatures and compounds in solid-state fermentation systems. Our work illustrated the vital impact of interaction variability mediated by Pediococcus spp. for microbial assembly and metabolites, as well as in forming temperature. These results emphasized the functional role of Daqu microbiota in metabolites and heat production and the importance of cooperation in improving the fermentation quality.IMPORTANCEThe stable and high-quality saccharifying and fermenting starter in traditional solid-state fermentation was the prerequisite for liquor brewing. An imbalance of microbial homeostasis in fermentation can adversely impact production quality. Identification of such critical microorganisms and verifying their associations with other fermentation parameters pose a challenge in a traditional fermentation environment. To enhance the quality of spontaneous fermented products, strategies such as bioaugmentation or the control of harmful microorganisms would be employed. This work started with the differences in high-temperature Daqu metabolites to explore a series of functional microorganisms that could potentially contribute to product disparities, and found that the differences in interactions facilitated directly or indirectly by Pediococcus spp. seriously affected the development of microbial communities and metabolites, as well as the formation of the microenvironment. This study not only identified functional microbiota in Daqu that affected fermentation quality, but also demonstrated how microorganisms interact to affect the fermentation system, which would provide guidance for microbial supervision in the actual production process. Besides, the application of isothermal microcalorimetry in this study was helpful for us to understand the heat production capacity of microorganisms and their adaptability to the environment. This study presented a commendable framework for improving and controlling the quality of traditional fermentation and inspired further investigations in similar systems.

Metagenome-assembled genome reveals species and functional composition of Jianghan chicken gut microbiota and isolation of Pediococcus acidilactic with probiotic properties.

BACKGROUND: Chickens are one of the most widely farmed animals worldwide and play a crucial role in meat and egg production. Gut microbiota is essential for chickens' health, disease, growth, and egg production. However, native chickens such as Jianghan chickens have better meat and egg production quality than centralized chickens, their intestinal microbial diversity is richer, and the potential gut microbial resources may bring health benefits to the host. RESULTS: The bacterial species composition in the gut microbiota of Jianghan chickens is similar to that of other chicken breeds, with Phocaeicola and Bacteroides being the most abundant bacterial genera. The LEfSe analysis revealed significant differences in species composition and functional profiles between samples from Jingzhou and the other three groups. Functional annotation indicated that the gut microbiota of Jianghan chickens were dominated by metabolic genes, with the highest number of genes related to carbohydrate metabolism. Several antibiotic resistance genes (ARGs) were found, and the composition of ARGs was similar to that of factory-farmed chickens, suggesting that antibiotics were widely present in the gut microbiota of Jianghan chickens. The resistance genes of Jianghan chickens are mainly carried by microorganisms of the Bacteroidota and Bacillota phylum. In addition, more than 829 isolates were selected from the microbiota of Jianghan chickens. Following three rounds of acid and bile tolerance experiments performed on all the isolated strains, it was determined that six strains of Pediococcus acidilactici exhibited consistent tolerance. Further experiments confirmed that three of these strains (A4, B9, and C2) held substantial probiotic potential, with P. acidilactici B9 displaying the highest probiotic potential. CONCLUSIONS: This study elucidates the composition of the intestinal microbiota and functional gene repertoire in Jianghan chickens. Despite the absence of antibiotic supplementation, the intestinal microbial community of Jianghan chickens still demonstrates a profile of antibiotic resistance genes similar to that of intensively reared chickens, suggesting resistance genes are prevalent in free-ranging poultry. Moreover, Jianghan and intensively reared chickens host major resistance genes differently, an aspect seldom explored between free-range and pastured chickens. Furthermore, among the 829 isolates, three strains of P. acidilatici exhibited strong probiotic potential. These findings provide insights into the unique gut microbiota of Jianghan chickens and highlight potential probiotic strains offering benefits to the host. Video Abstract.

Probiotic potential and wound-healing activity of Pediococcus pentosaceus strain AF2 isolated from Herniaria glabra L. which is traditionally used to make yogurt.

Probiotics have been a part of our lives for centuries, primarily through fermented foods. They find applications in various fields such as food, healthcare, and agriculture. Nowadays, their utilization is expanding, highlighting the importance of discovering new bacterial strains with probiotic properties suitable for diverse applications. In this study, our aim was to isolate new probiotic bacteria. Herniaria glabra L., a plant traditionally used for yogurt making in some regions and recognized in official medicine in many countries, was chosen as the source for obtaining probiotic bacteria. We conducted bacterial isolation from the plant, molecularly identified the isolated bacteria using 16S rRNA sequencing, characterized their probiotic properties, and assessed their wound-healing effects. As a result of these studies, we identified the bacterium isolated from the plant as Pediococcus pentosaceus strain AF2. We found that the strain AF2 exhibited high resistance to conditions within the gastrointestinal tract. Our reliability analysis showed that the isolate had γ-hemolytic activity and displayed sensitivity to certain tested antibiotics. At the same time, AF2 did not show gelatinase and DNase activity. We observed that the strain AF2 produced metabolites with inhibitory activity against E. coli, B. subtilis, P. vulgaris, S. typhimurium, P. aeruginosa, K. pneumoniae, E. cloacae, and Y. pseudotuberculosis. The auto-aggregation value of the strain AF2 was calculated at 73.44%. Coaggregation values against E. coli and L. monocytogenes bacteria were determined to be 56.8% and 57.38%, respectively. Finally, we tested the wound-healing effect of the strain AF2 with cell culture studies and found that the strain AF2 promoted wound healing.

Isolation, identification, and stability of sourdough microbiota from spontaneously fermented Norwegian legumes.

Fermentation has recently been rediscovered as an attractive technique to process legumes, as it can improve the nutritional quality and value of the end product. This study investigated the dynamics and stability of the microbial communities in spontaneously fermented sourdoughs made from flours of two cultivars of faba beans and two cultivars of peas. Sourdoughs were established by the backslopping technique, and the microbial development at 22 °C and 30 °C was followed by culture dependent and culture independent methods. The utilization of substrates and formation of metabolites were also determined by high-performance liquid chromatography. A stable pH was reached in all the sourdoughs after 11-15 days of daily backslopping. Lactic acid bacteria and yeast from pH stable sourdoughs were isolated, characterized and identified. The fermentation temperature influenced the development of the microbial community and the substrate utilization during spontaneous fermentation. In the 30 °C fermentations, one species dominated (Lactiplantibacillus plantarum/pentosus), a lower pH was achieved, and the available substrates were more extensively converted. The 22 °C fermentation resulted in a more diverse microbial community (Lactiplantibacillus, Leuconostoc, Pediococcus), a higher pH, and more residual substrates were available after fermentation. Yeasts were only detected in one of the pea sourdoughs fermented at 30 °C, with Saccharomyces cerevisiae being the dominant species. Nearly all sourdoughs were depleted of maltose after 24 h fermentation cycles, and higher levels of lactic and acetic acid were detected in 30 °C fermen-tations. This research adds to our understanding of the autochthonous microbial community present in faba beans and peas as well as their natural capacity to establish themselves and ferment legume flours. These findings enhance the possibilities of utilizing and improving plant based protein sources.

Various cold storage-backslopping cycles show the robustness of Limosilactobacillus fermentum IMDO 130101 as starter culture for Type 3 sourdough production.

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

The rise of the sourdough: Genome-scale metabolic modeling-based approach to design sourdough starter communities with tailored-made properties.

Sourdough starters harbor microbial consortia that benefit the final product's aroma and volume. The complex nature of these spontaneously developed communities raises challenges in predicting the fermentation phenotypes. Herein, we demonstrated for the first time in this field the potential of genome-scale metabolic modeling (GEMs) in the study of sourdough microbial communities. Broad in-silico modeling of microbial growth was applied on communities composed of yeast (Saccharomyces cerevisiae) and different Lactic Acid Bacteria (LAB) species, which mainly predominate in sourdough starters. Simulations of model-represented communities associated specific bacterial compositions with sourdough phenotypes. Based on ranking the phenotypic performances of different combinations, Pediococcus spp. - Lb. sakei group members were predicted to have an optimal effect considering the increase in S. cerevisiae growth abilities and overall CO2 secretion rates. Flux Balance Analysis (FBA) revealed mutual relationships between the Pediococcus spp. - Lb. sakei group members and S. cerevisiae through bidirectional nutrient dependencies, and further underlined that these bacteria compete with the yeast over nutrients to a lesser extent than the rest LAB species. Volatile compounds (VOCs) production was further modeled, identifying species-specific and community-related VOCs production profiles. The in-silico models' predictions were validated by experimentally building synthetic sourdough communities and assessing the fermentation phenotypes. The Pediococcus spp. - Lb. sakei group was indeed associated with increased yeast cell counts and fermentation rates, demonstrating a 25 % increase in the average leavening rates during the first 10 fermentation hours compared to communities with a lower representation of these group members. Overall, these results provide a possible novel strategy towards the de-novo design of sourdough starter communities with tailored-made characterizations, including a shortened leavening period.

Depiction of the In Vitro and Genomic Basis of Resistance to Hop and High Hydrostatic Pressure of Lactiplantibacillus plantarum Isolated from Spoiled Beer.

Among the beer-spoiling microorganisms, the dominant ones belong to the genera Lactobacillus, Leuconostoc, Oenococcus, and Pediococcus. It is assumed that resistance to hop bitters correlates with resistance to other factors and can significantly impact the brewing industry. Beer preservation with high hydrostatic pressure eliminates the spoiling microorganisms while preserving all desired properties of the beer. Here, we present comprehensive in vitro and genomic analysis of the beer-spoiling Lactiplantibacillus plantarum KKP 3573 capacity to resist hop and high hydrostatic pressure. Lp. plantarum KKP 3573 is a strain isolated from spoiled beer. Our finding suggests that the growth rate of the strain depends on the medium variant, where a small concentration of beer (5 IBU) stimulates the growth, suggesting that the limited concentration has a positive effect on cell growth. At the same time, increased concentrations of 20 IBU, 30 IBU, and pure beer 43.6 IBU decreased the growth rate of the KKP 3573 strain. We observed that higher extract content in the pressurized beer increased microbial survivability. The wort and Vienna Lager beer can stimulate the baroprotective effect. The taxonomy of the novel strain was confirmed after whole genome sequencing (WGS) and comparative genomic analysis. More specifically, it contains a chromosome of 3.3 Mb with a GC content of 44.4%, indicative of the Lp. plantarum species. Accordingly, it possesses high genomic similarity (>98%) with other species members. Annotation algorithms revealed that the strain carries several genes involved in resistance to stress, including extreme temperature, hop bitters and high pressure, and adaptation to the brewing environment. Lastly, the strain does not code for toxins and virulence proteins and cannot produce biogenic amines.

Complete Genome Sequencing and Bacteriocin Functional Characterization of Pediococcus ethanolidurans CP201 from Daqu.

This study aims to sequence the whole genome of Pediococcus ethanolidurans CP201 isolated from Daqu and determine the anti-corrosion ability of bacteriocins on chicken breast. The whole genome sequence information of P. ethanolidurans CP201 was analyzed, and its gene structure and function were explored. It was found that gene1164 had annotations in the NR, Pfam, and Swiss-Prot databases, and was related to bacteriocins. The exogenous expression of the bacteriocin gene Pediocin PE-201 was analyzed based on the pET-21b vector and the host BL21, and the corresponding bacteriocin was successfully expressed under the induction of IPTG. After purification by NI-NTA column, enterokinase treatment, membrane dialysis concentration treatment, and SDS-PAGE electrophoresis, the molecular weight was about 6.5 kDa and the purity was above 90%. By applying different concentrations of bacteriocin to chicken breast with different levels of contamination, the control of pathogenic bacteria, the ordinary contamination level (OC) group, and the high contamination level (MC) group could be completely achieved with 25 mg/L bacteriocin. In conclusion, the bacteriocin produced by the newly isolated CP201 can be applied to the preservation of meat products to prevent the risk of food-borne diseases.

NMR-Based Metabolomic Study on Phaseolus vulgaris Flour Fermented by Lactic Acid Bacteria and Yeasts.

In recent years, fermented foods have attracted increasing attention due to their important role in the human diet, since they supply beneficial health effects, providing important sources of nutrients. In this respect, a comprehensive characterization of the metabolite content in fermented foods is required to achieve a complete vision of physiological, microbiological, and functional traits. In the present preliminary study, the NMR-based metabolomic approach combined with chemometrics has been applied, for the first time, to investigate the metabolite content of Phaseolus vulgaris flour fermented by different lactic acid bacteria (LAB) and yeasts. A differentiation of microorganisms (LAB and yeasts), LAB metabolism (homo- and heterofermentative hexose fermentation), LAB genus (Lactobacillus, Leuconostoc, and Pediococcus), and novel genera (Lacticaseibacillus, Lactiplantibacillus, and Lentilactobacillus) was achieved. Moreover, our findings showed an increase of free amino acids and bioactive molecules, such as GABA, and a degradation of anti-nutritional compounds, such as raffinose and stachyose, confirming the beneficial effects of fermentation processes and the potential use of fermented flours in the production of healthy baking foods. Finally, among all microorganisms considered, the Lactiplantibacillus plantarum species was found to be the most effective in fermenting bean flour, as a larger amount of free amino acids were assessed in their analysis, denoting more intensive proteolytic activity.

Comparative genomics reveals key molecular targets for mutant Pediococcus pentosaceus C23221 producing pediocin.

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

In-vitro evaluation of the probiotic potential and the fermentation profile of Pediococcus and Enterococcus strains isolated from Moroccan camel milk.

The promotion of human health through natural approaches like functional foods and probiotics is in high demand. The medicinal plants are the major feed of Moroccan dromedary, which improves the functional properties of their milk. A few studies have reported the probiotic and functional aptitudes of lactic acid bacteria (LAB) of this milk. In this context, our study aimed to identify LAB isolated from Moroccan raw camel milk and investigate their probiotic features and their fermentation profile. The molecular identification of twelve isolates indicated that they belong to Pediococcus pentosaceus, Enterococcus faecium, and Enterococcus durans. All LAB strains displayed high tolerance to gastrointestinal conditions (survival rate of 31.85-96.52% in pH 2.5, 35.23-99.05% in 0.3 bile salts, and 26.9-90.96% in pepsin), strong attachment abilities (auto-aggregation and hydrophobicity ranged from 28.75 to 95.9% and from 80.47 to 96.37%, respectively), and high co-aggregation ability with pathogenic bacteria. Importantly, they did not present antibiotic resistance or hemolytic activity. Our LAB strains demonstrated antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Salmonella enterica. Moreover, they could acidify cow milk (ΔpH of 2.55 after 24 h) and improve its antioxidant ability (inhibition of 36.77% of DPPH). Based on the multivariate analysis, Pediococcus pentosaceus Pd24, Pd29, Pd38, Enterococcus faecium Ef18, and Enterococcus durans Ed22 were selected as the most promising probiotics. Therefore, we propose that Pediococcus pentosaceus isolated from camel milk could be used as potential probiotic strains and/or starter cultures in functional milk fermentation.

Genomic, metabolomic, and functional characterisation of beneficial properties of Pediococcus pentosaceus ST58, isolated from human oral cavity.

Bacteriocins produced by lactic acid bacteria are proteinaceous antibacterial metabolites that normally exhibit bactericidal or bacteriostatic activity against genetically closely related bacteria. In this work, the bacteriocinogenic potential of Pediococcus pentosaceus strain ST58, isolated from oral cavity of a healthy volunteer was evaluated. To better understand the biological role of this strain, its technological and safety traits were deeply investigated through a combined approach considering physiological, metabolomic and genomic properties. Three out of 14 colonies generating inhibition zones were confirmed to be bacteriocin producers and, according to repPCR and RAPD-PCR, differentiation assays, and 16S rRNA sequencing it was confirmed to be replicates of the same strain, identified as P. pentosaceus, named ST58. Based on multiple isolation of the same strain (P. pentosaceus ST58) over the 26 weeks in screening process for the potential bacteriocinogenic strains from the oral cavity of the same volunteer, strain ST58 can be considered a persistent component of oral cavity microbiota. Genomic analysis of P. pentosaceus ST58 revealed the presence of operons encoding for bacteriocins pediocin PA-1 and penocin A. The produced bacteriocin(s) inhibited the growth of Listeria monocytogenes, Enterococcus spp. and some Lactobacillus spp. used to determine the activity spectrum. The highest levels of production (6400 AU/ml) were recorded against L. monocytogenes strains after 24 h of incubation and the antimicrobial activity was inhibited after treatment of the cell-free supernatants with proteolytic enzymes. Noteworthy, P. pentosaceus ST58 also presented antifungal activity and key metabolites potentially involved in these properties were identified. Overall, this strain can be of great biotechnological interest towards the development of effective bio-preservation cultures as well as potential health promoting microbes.

Isolation, identification and safety evaluation of OTA-detoxification strain Pediococcus acidilactici NJB421 and its effects on OTA-induced toxicity in mice.

Ochratoxin A (OTA) is a potent mycotoxin found in foods and feeds, posing a health risk to animals and humans. Biological detoxification of OTA is considered a promising method, and some bacteria and fungi which can degrade OTA are isolated. However, research on safety and alleviating toxic effects are scarce. This study aims to isolate OTA-detoxification probiotics from natural samples and evaluate their safety and protective effects in mice. Here, a new OTA-detoxification strain named Pediococcus acidilactici NJB421 (P. acidilactici NJB421) was isolated from cow manure, which exhibited a removal rate of OTA at 48.53% for 48 h. P. acidilactici NJB421 exhibited high temperature resistance, acid tolerance, 0.3% bile salt and 1.4% trypsin resistance. The safety evaluation showed that P. acidilactici NJB421 at 2 × 108 CFU/per mouse had no abnormalities in body weight, organ indices, ALT, AST and ALP activities, BUN, CRE and TP contents. And P. acidilactici NJB421 alleviated the decreases in body weight, organ indices and small intestinal length, and alleviated intestinal injury, liver injury and kidney injury. These results suggest P. acidilactici NJB421 is safe and has protection against OTA poisoning, which provides a new OTA-detoxification strain for livestock and food industries.

Effects of Lactic Acid Bacteria Isolated from Equine on Salmonella-Infected Gut Mouse Model.

The aim of this study was to evaluate the antibacterial potential of lactic acid bacteria (Weissella confuse, Pediococcus acidilactici, and Ligilactobacillus equi) isolated from healthy equine in Wuhan against Salmonella Typhimurium CVCC542-induced mice model on intestinal microflora. In previous studies, these isolated strains showed good probiotic potentials in vitro. In this study, fifty healthy mice were randomly divided into five groups, the blank control group, the control group, the Pediococcus acidilactici group (1 × 108 CFU/day), the Ligilactobacillus equi group (1 × 108 CFU/day), and the Weissella confuse group (1 × 108 CFU/day). The body weight in control group and Weissella confuse group showed significant decreased (P < 0.05, P < 0.01), while Pediococcus acidilactici group and Ligilactobacillus equi group showed good recovering after treatments. The lowest diarrhea rate was shown in Ligilactobacillus equi group after treatment. In histopathology, Ligilactobacillus equi group showed the least structural damage in duodenum, and all probiotic treatment groups showed less damage in cecum. The sequence data and optical transform unit showed that Pediococcus acidilactici group and Ligilactobacillus equi group had higher number than control group, while the diversity data showed that the control group and Weissella confuse group had lower diversity in cecum. Microbial community analysis showed increased abundance of Firmicutes, Bacteroidetes, uncultured_bacterium_f_Muribaculaceae, and Lactobacillus in treatment groups, while potential microbes that can induce intestinal diseases such as Verrucomicrobia, Akkermansia, and Lachnospiraceae_NK4A136_group decreased in the treatment groups. In conclusion, lactic acid bacteria isolated from the healthy horses could alleviate the infection of Salmonella and regulate intestinal flora.

Genomic Analyses of Pediococcus pentosaceus ST65ACC, a Bacteriocinogenic Strain Isolated from Artisanal Raw-Milk Cheese.

Pediococcus pentosaceus ST65ACC was obtained from a Brazilian artisanal cheese (BAC) and characterized as bacteriocinogenic. This strain presented beneficial properties in previous studies, indicating its potential as a probiotic candidate. In this study, we aimed to carry out a genetic characterization based on whole-genome sequencing (WGS), including taxonomy, biotechnological properties, bacteriocin clusters and safety-related genes. WGS was performed using the Illumina MiSeq platform and the genome was annotated with the Prokaryotic Genome Annotation (Prokka). P. pentosaceus ST65ACC taxonomy was investigated and bacteriocin genes clusters were identified by BAGEL4, metabolic pathways were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and safety-related genes were checked. P. pentosaceus ST65ACC had a total draft genome size of 1,933,194 bp with a GC content of 37.00%, and encoded 1950 protein coding sequences (CDSs), 6 rRNA, 55 tRNA, 1 tmRNA and no plasmids were detected. The analysis revealed absence of a CRISPR/Cas system, bacteriocin gene clusters for pediocin PA-1/AcH and penocin-A were identified. Genes related to beneficial properties, such as stress adaptation genes and adhesion genes, were identified. Furthermore, genes related to biogenic amines and virulence-related genes were not detected. Genes related to antibiotic resistance were identified, but not in prophage regions. Based on the obtained results, the beneficial potential of P. pentosaceus ST65ACC was confirmed, allowing its characterization as a potential probiotic candidate.

Exploration of Antidiabetic, Cholesterol-Lowering, and Anticancer Upshot of Probiotic Bacterium Pediococcus pentosaceus OBK05 Strain of Buttermilk.

Chronic metabolic disorders such as hyperglycemia (diabetes), hyperlipidemia (high cholesterol), and cancer have become catastrophic diseases worldwide. Accordingly, probiotic intervention is a new approach for alleviating catastrophic diseases. In the present study, Pediococcus pentosaceus OBK05 was investigated as a potential probiotic bacterium for antidiabetic, cholesterol-lowering, and anticancer activities by in vitro and in vivo studies. Cell-free supernatant (CFS) of OBK05 showed potent antidiabetic activity by inhibition of α-amylase (72 ± 0.9%) and α-glucosidase (61 ± 0.8%) activity in vitro when compared to that of acarbose as standard (86 ± 0.9%). Furthermore, the in vivo cholesterol-lowering activity of OBK05 was studied using cholesterol-fed hypercholesterolemic mice. When compared to the cholesterol-fed group, the OBK05-intervened cholesterol-fed mice group had significantly lowered the levels of lipids and showed significantly lower lipid droplet accumulation in the histology of hepatocytes. Similarly, CFS exhibited higher anticancer activity (87.57 ± 1.27%) against HT-29 cells with an IC50 of 54.51 ± 1.8. Fluorescence-activated cell sorting (FACS) analysis revealed that CFS induced the cell cycle arrest by inhibiting the G1 to S phase transition. Further, in vivo anticancer activities were confirmed in BALB/c mice models, which were divided into four groups and held for 16 weeks. HT-29 cells (5×109/mice) were injected subcutaneously twice (0 and 2nd week), and OBK05 (3 ×105 CFU/mL) was given orally to the respective groups. The OBK05-intervened HT-29 cell-induced mice group showed significant improvement at the histological level and alleviated the degree of atypia in the intestine.

Correlation between microbial communities and key odourants in fermented capsicum inoculated with Pediococcus pentosaceus and Cyberlindnera rhodanensis.

BACKGROUND: Fermented capsicum (i.e. pickled pepper) is one of the most popular fermented vegetables. However, the effect of inoculated microbial fermentation on pickled pepper is not yet fully understood. RESULTS: Cyberlindnera rhodanensis J52 with a rich ester flavour and Pediococcus pentosaceus AL with a strong inhibitory effect on foodborne pathogenic bacteria were selected to prepare single- and double-strain fermented capsicum under low salt (< 10 g L-1 sodium chloride) conditions. The inhibition zone of P. pentosaceus AL against Escherichia coli was up to 44 mm in diameter. Biochemical indicator analyses found that co-fermentation of P. pentosaceus AL and C. rhodanensis J52 changed the contents of vitamin C and short-chain fatty acids. Analysis of microbial diversity and volatile metabolome showed that 125 microbial species and 72 volatile compounds were detected, and P. pentosaceus was the dominant bacterium that inhibited the growth of other bacteria, while C. rhodanensis was the fungus that contributed the most to flavour. Correlation analysis between microorganisms and flavour compounds showed 725 correlations, and 124 microbial species may have participated in the formation of 69 compounds. Furthermore, 10 and 29 correlations were detected between P. pentosaceus AL or C. rhodanensis J52 and flavour compounds, respectively. Among them, 3-methyl-1-butanol acetate is speculated to be the main substance affecting the flavour of fermented capsicum by inoculation with C. rhodanensis J52. CONCLUSION: The inoculation of P. pentosaceus and C. rhodanensis had a significant impact on the microbial community and volatile compounds of fermented capsicum and helped to improve its organoleptic qualities. © 2022 Society of Chemical Industry.

Effects of Pediococcus acidilactici and Rhizopus Oryzae on microbiota and metabolomic profiling in fermented dry-cure mutton sausages.

Traditional fermentation of dry mutton sausages (DMSs) commonly causes some quality problems. In this study, high-throughput sequencing (HTS) and metabolomics were used to study the microorganisms and metabolites of DMSs produced by mixed strains of Pediococcus acidilactici and Rhizopus Oryzae, to discover the effect of inoculated fermentation (IF) on the metabolites of DMSs. A total of 92 volatile metabolites and 58 non-volatile significantly different metabolites were identified in DMSs. After inoculated fermentation, the volatile types increased, and the total contents of aldehydes and esters were enhanced at the end of fermentation. In addition, the levels of amino acids, fatty acids, palmitoyl carnitine, acetyl-l-carnitine, and betaine were also improved. The correlation analysis showed that the P. acidilactici and R. Oryzae were highly correlated with a variety of metabolites. Together, these findings provide excellent strain resources for improving the quality of mutton sausages.

Genomic analysis and in vivo efficacy of Pediococcus acidilactici as a potential probiotic to prevent hyperglycemia, hypercholesterolemia and gastrointestinal infections.

Lactic acid bacteria are the well acknowledged probiotics that can cure a variety of diseases. In this study, we observed the in vivo potentials of Pediococcus to treat hyperglycemia, hypercholesterolemia and gastrointestinal infections. A total of 77 Lactobacillus were isolated from the milk of 10 cows and 10 goats, four of those strains inhibited both carbohydrates-hydrolyzing enzymes, α-glucosidase, and α-amylase. They all showed antagonistic effects on pathogenic E. coli and S. Typhimurium which were confirmed by performing pathogen challenge test and visualizing on Electron microscopy. 16S rRNA gene sequence identified that all four strains belong to Pediococcus genus which were further distinguished as Pediococcus acidilactici by pheS gene sequence. Whole genome sequence analysis revealed their non-pathogenic properties for human and the presence of probiotic genes responsible for stress resistance, immunomodulation, adhesion, metal and drug resistance. In vivo trial with diabetes-induced mice ascertained that all Pediococcus acidilactici had significant potentials to reduce elevated glucose and low-density lipoprotein level in blood. Interestingly, two out of four strains were significantly more effective (p < 0.0001 each) than metformin in reducing the blood glucose level. This in vivo study demonstrated that Pediococcus acidilactici might be a promising probiotic to prevent hyperglycemia, hypercholesterolemia and gastrointestinal infections.

Beneficial features of pediococcus: from starter cultures and inhibitory activities to probiotic benefits.

Pediococci are lactic acid bacteria (LAB) which have been used for centuries in the production of traditional fermented foods. There fermentative abilities were explored by the modern food processing industry in use of pediococci as starter cultures, enabling the production of fermented foods with distinct characteristics. Furthermore, some pediococci strains can produce bacteriocins and other antimicrobial metabolites (AMM), such as pediocins, which are increasingly being explored as bio-preservatives in various food matrices. Due to their versatility and inhibitory spectrum, pediococci bacteriocins and AMM are being extensively researched not only in the food industry, but also in veterinary and human medicine. Some of the pediococci were evaluated as potential probiotics with different beneficial areas of application associated with human and other animals' health. The main taxonomic characteristics of pediococci species are presented here, as well as and their potential roles and applications as starter cultures, as bio-preservatives and as probiotic candidates.