The predominant lactic acid bacteria and yeasts involved in the spontaneous fermentation of millet during the production of the traditional porridge Hausa koko in Ghana.

Spontaneous fermentation of cereals like millet involves a diverse population of microbes from various sources, including raw materials, processing equipment, fermenting receptacles, and the environment. Here, we present data on the predominant microbial species and their succession at each stage of the Hausa koko production process from five regions of Ghana. The isolates were enumerated using selective media, purified, and phenotypically characterised. The LAB isolates were further characterised by 16S rRNA Sanger sequencing, typed using (GTG)5 repetitive-PCR, and whole genome sequencing, while 28S rRNA Sanger sequencing was performed for yeast identification. The pH of the millet grains ranged from mean values of 6.02-6.53 to 3.51-3.99 in the final product, depending on the processors. The mean LAB and yeast counts increased during fermentation then fell to final counts of log 2.77-3.95 CFU/g for LAB and log 2.10-2.98 CFU/g for yeast in Hausa koko samples. At the various processing stages, the counts of LAB and yeast revealed significant variations (p < 0.0001). The species of LAB identified in this study were Limosilactobacillus pontis, Pediococcus acidilactici, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Pediococcus pentosaceus, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Schleiferilactobacillus harbinensis, and Weissella confusa. The yeasts were Saccharomyces cf. cerevisiae/paradoxus, Saccharomyces cerevisiae, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis. The identification and sequencing of these novel isolates and how they change during the fermentation process will pave the way for future controlled fermentation, safer starter cultures, and identifying optimal stages for starter culture addition or nutritional interventions. These LAB and yeast species are linked to many indigenous African fermented foods, potentially acting as probiotics in some cases. This result serves as the basis for further studies into the technological and probiotic potential of these Hausa koko microorganisms.

New insight into protective effect against oxidative stress and biosynthesis of exopolysaccharides produced by Lacticaseibacillus paracasei NC4 from fermented eggplant.

Fermented eggplant is a traditional fermented food, however lactic acid bacteria capable of producing exopolysaccharide (EPS) have not yet been exploited. The present study focused on the production and protective effects against oxidative stress of an EPS produced by Lacticaseibacillus paracasei NC4 (NC4-EPS), in addition to deciphering its genomic features and EPS biosynthesis pathway. Among 54 isolates tested, strain NC4 showed the highest EPS yield and antioxidant activity. The maximum EPS production (2.04 ± 0.11 g/L) was achieved by culturing in MRS medium containing 60 g/L sucrose at 37 °C for 48 h. Under 2 mM H2O2 stress, the survival of a yeast model Saccharomyces cerevisiae treated with 0.4 mg/mL NC4-EPS was 2.4-fold better than non-treated cells, which was in agreement with the catalase and superoxide dismutase activities measured from cell lysates. The complete genome of NC4 composed of a circular chromosome of 2,888,896 bp and 3 circular plasmids. The NC4 genome comprises more genes with annotated function in nitrogen metabolism, phosphorus metabolism, cell division and cell cycle, and iron acquisition and metabolism as compared to other reported L. paracasei. Of note, the eps gene cluster is not conserved across L. paracasei. Pathways of sugar metabolism for EPS biosynthesis were proposed for the first time, in which gdp pathway only present in few plant-derived bacteria was identified. These findings shed new light on the cell-protective activity and biosynthesis of EPS produced by L. paracasei, paving the way for future efforts to enhance yield and tailor-made EPS production for food and pharmaceutical industries.

A review on fermented vegetables: Microbial community and potential upgrading strategy via inoculated fermentation.

Fermentation is a traditional method utilized for vegetable preservation, with microorganisms playing a crucial role in the process. Nowadays, traditional spontaneous fermentation methods are widely employed, which excessively depend on the microorganisms attached to the surface of raw materials, resulting in great difficulties in ideal control over the fermentation process. To achieve standardized production and improve product quality, it is essential to promote inoculated fermentation. In this way, starter cultures can dominate the fermentation processes successfully. Unfortunately, inoculated fermentation has not been thoroughly studied and applied. Therefore, this paper provides a systematic review of the potential upgrading strategy of vegetable fermentation technology. First, we disclose the microbial community structures and succession rules in some typical spontaneously fermented vegetables to comprehend the microbial fermentation processes well. Then, internal and external factors affecting microorganisms are explored to provide references for the selection of fermented materials and conditions. Besides, we widely summarize the potential starter candidates with various characteristics isolated from spontaneously fermented products. Subsequently, we exhibited the inoculated fermentation strategies with those isolations. To optimize the product quality, not only lactic acid bacteria that lead the fermentation, but also yeasts that contribute to aroma formation should be combined for inoculation. The inoculation order of the starter cultures also affects the microbial fermentation. It is equally important to choose a proper processing method to guarantee the activity and convenience of starter cultures. Only in this way can we achieve the transition from traditional spontaneous fermentation to modern inoculated fermentation.

Evaluation of Menopausal Syndrome Relief and Anti-Obesity Efficacy of the Korean Fermented Food Doenjang: A Randomized, Double-Blind Clinical Trial.

Foods that help improve menopausal syndrome are being studied worldwide. Doenjang is a traditional Korean fermented soybean food with potential health benefits for menopausal women. In this clinical trial using Doenjang, we aimed to compare the effectiveness of traditional Doenjang and commercial Doenjang in menopausal women. Furthermore, we compared whether Doenjang has a better effect if the number of beneficial microbes is higher. The analyses included the following groups: traditional Doenjang containing either a high dose (HDC; n = 18) or low dose (LDC; n = 18) of beneficial microbes and commercial Doenjang (CD; n = 20). The Kupperman index and hematological changes were examined before and after the use of Doenjang pills. The effects of Doenjang on obesity and body composition were studied before and after ingestion. Lastly, the microorganisms and short-chain fatty acid changes in the stool were compared. The Kupperman index decreased after Doenjang consumption in all three groups, with the greatest decrease in the LDC group. Only the groups that took traditional Doenjang pills exhibited reduced LDL cholesterol. No changes in obesity and inflammation-related indicators were observed. The number of Firmicutes, associated with obesity, decreased in the CD group but the numbers of Bacteroidetes increased in the HDC and CD groups. Thus, traditional Doenjang is more effective in alleviating menopausal syndrome than commercial Doenjang. Further research on the anti-obesity effect or changes in microbiomes and short-chain fatty acids in feces is needed.

Casein hydrolysate in naturally-fermented buckwheat sourdough: Effects on fermented and physicochemical characteristics, texture, and bacterial microbial composition.

The effect of a casein hydrolysate (CH) on the fermentation and quality of a naturally-fermented buckwheat sourdough (NFBS) were investigated, through assessing the fermentation characteristics, carbohydrate and protein degradation, texture, and bacterial composition of NFBS. According to the assaying data, CH might both increase the amount of lactic acid bacteria by 2.62 % and shorten the fermentation period by at least 3 h, subsequently leading to enhanced degradation of carbohydrate and protein, accompanied by a softer texture. More importantly, CH increased the relative abundance of lactobacillus in NFBS, making it the dominant bacterial genus and inhibited the growth of spoilage bacteria. In addition, Spearman correlation analysis indicated that the pH value, lactic and acetic acid contents, carbohydrates, protease activity, and these textural indices like hardness, elasticity, and adhesion had a positive/negative correlation with the bacterial composition of NFBS (Spearman correlation coefficient: -0.93-0.95). CH was thus regarded to be helpful to NFBS processing and production mainly by shortening its fermentation time, improving its fermentation performance, causing a finer texture and microstructure, and changing bacterial composition.

Improvement mechanism of volatile flavor in fermented tilapia surimi by cooperative fermentation of Pediococcus acidilactici and Latilactobacillus sakei: Quantization of microbial contribution through influence of genus.

Single starter can hardly improve the volatile flavor of fermented fish surimi. In this study, the changes of volatile compounds (VCs) and microbial composition during cooperative fermentation of Latilactobacillus sakei and Pediococcus acidilactici were studied by headspace solid-phase microextraction gas chromatography-mass spectrometry and 16S rRNA gene high-throughput sequencing. During cooperative fermentation, most VCs and the abundance of Latilactobacillus and Lactococcus significantly increased, while Pediococcus, Acinetobacter, and Macrococcus obviously decreased. After evaluation of correlation and abundance of each genus, Latilactobacillus and Lactococcus possessed the highest influence on the formation of volatile flavor during cooperative fermentation. Compared with the natural fermentation, cooperative fermentation with starters significantly enhanced most of pleasant core VCs (odor activity value≥1), but inhibited the production of trimethylamine and methanethiol, mainly resulting from the absolutely highest influence of Latilactobacillus. Cooperative fermentation of starters is an effective method to improve the volatile flavor in the fermented tilapia surimi.

Genomic characterization and probiotic potential assessment of an exopolysaccharide-producing strain Pediococcus pentosaceus LL-07 isolated from fermented meat.

BACKGROUND: The genomic information available for Pediococcus pentosaceus is primarily derived from fermented fruits and vegetables, with less information available from fermented meat. P. pentosaceus LL-07, a strain isolated from fermented meat, has the capability of producing exopolysaccharides (EPS). To assess the probiotic attributes of P. pentosaceus LL-07, we conducted whole-genome sequencing (WGS) using the PacBio SequelIIe and Illumina MiSeq platforms, followed by in vitro experiments to explore its probiotic potential. RESULTS: The genome size of P. pentosaceus LL-07 is 1,782,685 bp, comprising a circular chromosome and a circular plasmid. Our investigation revealed the absence of a CRISPR/Cas system. Sugar fermentation experiments demonstrated the characteristics of carbohydrate metabolism. P. pentosaceus LL-07 contains an EPS synthesis gene cluster consisting of 13 genes, which is different from the currently known gene cluster structure. NO genes associated with hemolysis or toxin synthesis were detected. Additionally, eighty-six genes related to antibiotic resistance were identified but not present in the prophage, transposon or plasmid. In vitro experiments demonstrated that P. pentosaceus LL-07 was comparable to the reference strain P. pentosaceus ATCC25745 in terms of tolerance to artificial digestive juice and bile, autoaggregation and antioxidation, and provided corresponding genomic evidence. CONCLUSION: This study confirmed the safety and probiotic properties of P. pentosaceus LL-07 via complete genome and phenotype analysis, supporting its characterization as a potential probiotic candidate.

Survival of O157 and non-O157 shiga toxin-producing Escherichia coli in Korean style kimchi.

Korean style kimchi contaminated with Shiga toxin-producing Escherichia coli (STEC) O157:H7 was the cause of an outbreak in Canada from December 2021 to January 2022. To determine if this STEC O157:H7 has greater potential for survival in kimchi than other STEC, the outbreak strain and six other STEC strains (O26:H11, O91:H21, O103:H2, O121:H19, and two O157:H7) were inoculated individually at 6 to 6.5 log CFU/g into commercially sourced kimchi and incubation at 4 °C. At intervals of seven days inoculated and control kimchi was plated onto MacConkey agar to enumerate lactose utilising bacteria. The colony counts were interpreted as enumerating the inoculated STEC, since no colonies were observed on MacConkey agar plated with uninoculated kimchi. Over eight weeks of incubation the pH was stable at 4.10 to 4.05 and the STEC strains declined by 0.7-1.0 log, with a median reduction of 0.9 log. The linear rate of reduction of kimchi outbreak STEC O157:H7 was -0.4 log per 30 days (Slope Uncertainty 0.05), which was not significantly different from the other O157 and nonO157 STEC strains (P = 0.091). These results indicate that the outbreak was not due to the presence of strain better adapted to survival in kimchi than other STEC, and that STEC can persist in refrigerated Korean style kimchi with a minimal decline over the shelf-life of the product.

Standardized ileal digestibility of amino acids in Chinese fermented soybean meal from different sources fed to mid and late-gestating sows.

We determined apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values of crude protein (CP) and amino acids (AA) in fermented soybean meal from five different sources (FSBM 1 to 5) in China when fed to mid and late-gestating sows. Twenty-four parity four sows (12 at 30 d in gestation and 12 at 80 d in gestation) were fitted with a T-cannula in the distal ileum and used in this experiment. Sows were randomly assigned to a replicated 6 × 3 Youden square design including six diets and three periods. Six diets were provided for sows in mid and late gestation, including a nitrogen-free diet and five test diets containing 26% FSBM from different sources. Results showed that there were differences in AID and SID of CP among the different FSBM samples, but no differences between sow physiological stages were observed. Specifically, when mid-gestating sows were fed FSBM 2, the AID of CP was the lowest, whereas FSBM 3 exhibited a greater AID of CP when compared to the other FSBM samples (P < 0.01). Furthermore, during late gestation, FSBM 3 consistently had greater SID of CP when compared to other FSBM samples (P < 0.01). The ileal digestibility of most AA varied with different FSBM samples. In both mid and late gestation, differences (P < 0.05) were observed for AID of lysine, tryptophan, histidine, and arginine across different FSBM samples. Similarly, the AID of dispensable AA (cysteine, glutamine, and serine) also exhibited differences (P < 0.05) across different FSBM samples in both mid and late-gestating sows. For mid-gestating sows, SID differences relating to lysine, phenylalanine, tryptophan, threonine, and arginine were observed among different diets (P < 0.05). In late-gestating sows, SID values for lysine, tryptophan, leucine, and arginine differed across diets (P < 0.05). Furthermore, the ileal digestibility of some dispensable AA was influenced by physiological stage, as evidenced by greater AID and SID values for glycine, glutamine, cysteine, and serine in late-gestating sows when compared to mid-gestating sows (P < 0.01). In summary, our study determined AA ileal digestibility of different FSBM fed to mid and late-gestating sows. We observed that the AA ileal digestibility differed among five FSBM samples, but the physiological stage of sows did not affect the ileal digestibility of CP and most AA. Additionally, when formulating diets for sows, it is crucial to consider the nutritional value differences of FSBM.

Fermented soybean meal (FSBM) is obtained from the microbial fermentation of soybean meal, which reduces anti-nutritional factor levels and enhances other nutrient content. Substituting soybean meal with FSBM in piglet and growing pig diets improves nutrient digestibility. However, its nutritional value for sows remains unclear. Therefore, five sources of FSBM were fed to sows in mid and late gestation to evaluate apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values of amino acids (AA). We found that different FSBM samples impacted the SID value of AA when fed to gestating sows. Additionally, sow physiological stage influenced the SID of some dispensable AA. These findings provide valuable insights into the incorporation of FSBM into sow diets.

Our extended microbiome: The human-relevant metabolites and biology of fermented foods.

One of the key modes of microbial metabolism occurring in the gut microbiome is fermentation. This energy-yielding process transforms common macromolecules like polysaccharides and amino acids into a wide variety of chemicals, many of which are relevant to microbe-microbe and microbe-host interactions. Analogous transformations occur during the production of fermented foods, resulting in an abundance of bioactive metabolites. In foods, the products of fermentation can influence food safety and preservation, nutrient availability, and palatability and, once consumed, may impact immune and metabolic status, disease expression, and severity. Human signaling pathways perceive and respond to many of the currently known fermented food metabolites, though expansive chemical novelty remains to be defined. Here we discuss several aspects of fermented food-associated microbes and metabolites, including a condensed history, current understanding of their interactions with hosts and host-resident microbes, connections with commercial probiotics, and opportunities for future research on human health and disease and food sustainability.

Quantitative proteomic analysis reveals the mechanism and key esterase of ß-cypermethrin degradation in a bacterial strain from fermented food.

Beta-cypermethrin (ß-CY) residues in food are an important threat to human health. Microorganisms can degrade ß-CY residues during fermentation of fruits and vegetables, while the mechanism is not clear. In this study, a comprehensively investigate of the degradation mechanism of ß-CY in a food microorganism was conducted based on proteomics analysis. The ß-CY degradation bacteria Gordonia alkanivorans GH-1 was derived from fermented Pixian Doubanjiang. Its crude enzyme extract could degrade 77.11% of ß-CY at a concentration of 45 mg/L within 24 h. Proteomics analysis revealed that the ester bond of ß-CY is broken under the action of esterase to produce 3-phenoxy benzoic acid, which was further degraded by oxidoreductase and aromatic degrading enzyme. The up-regulation expression of oxidoreductase and esterase was confirmed by transcriptome and quantitative reverse transcription PCR. Meanwhile, the expression of esterase Est280 in Escherichia coli BL21 (DE3) resulted in a 48.43% enhancement in the degradation efficiency of ß-CY, which confirmed that this enzyme was the key enzyme in the process of ß-CY degradation. This study reveals the degradation mechanism of ß-CY by microorganisms during food fermentation, providing a theoretical basis for the application of food microorganisms in ß-CY residues.

Analysis of ester-producing performance in high-yield ethyl hexanoate yeast and the effect on metabolites in bio- enhanced Daqu, the starter for Baijiu and other traditional fermented foods.

AIMS: Ethyl hexanoate, one of the key flavor compounds in strong-flavor Baijiu. To improve the content of ethyl hexanoate in strong-flavor Baijiu, a functional strain with high yield of ethyl hexanoate was screened and its ester-producing performance was studied. METHODS AND RESULTS: Upon identification, the strain was classified as Candida sp. and designated as ZY002. Under optimal fermentation conditions, the content of ethyl hexanoate synthesized by ZY002 can be as high as 170.56 mg L-1. A fermentation test was carried out using the ZY002 strain bioaugmented Daqu to verify the role of the strain applied to Baijiu brewing. It was found that strain ZY002 could not only improve the moisture and alcohol contents of fermented grains but also diminish the presence of reducing sugar and crude starch. Furthermore, it notably amplified the abundance of flavor compounds. CONCLUSION: In this study, Candida sp. ZY002 with a high yield of ethyl hexanoate provided high-quality strain resources for the actual industrial production of Baijiu.

The addition of jogi, Micropogonias undulates, affects amino acid content in kimchi fermentation.

The effects of jogi (the fish Atlantic croaker, Micropogonias undulatus) on the production of physicochemical components, such as color, organic acids, and amino acids, in kimchi, a traditional fermented vegetable food of Korea, were determined. As fermentation progressed, the color change of jogi-added kimchi increased, but in comparison with that of the control group without jogi-added kimchi, was difficult to distinguish with the naked eye. Reducing sugar decreased in all experimental groups, and as fermentation progressed, kimchi with jogi showed a lower value. Acetic acid, citric acid, lactic acid, and ethanol, were highly produced in both types of kimchi, and above all, the jogi-baechu-kimchi group showed higher acetic acid and lactic acid contents than the control group. The increase and decrease of amino acids were similar in both types of kimchi. However, significantly, immediately after manufacture, the savory components aspartic acid and glutamic acid were detected higher than the control group. Subsequently, the fermentation tended to decrease as it progressed, but the content was higher than that of the control group. The above results show that jogi addition has a greater effect on the contents of amino acid, especially the savory component, than on the physicochemical components.

Exploring the Relationships Between Bacterial Community, Taste-Enhancing Peptides and Aroma in Thai Fermented Fish (Pla-ra).

As a traditional Thai condiment, Pla-ra is used to add flavor and richness to dishes. Nine treatment combinations of Pla-ra formulations created from 3 types of fish (Mor fish, Kradee fish, and Mor + Kradee fish) and 4 different carbohydrate sources (none, rice bran, roasted rice, and rice bran─roasted rice mixture) were studied through a 12 month fermentation period (1, 3, 5, 7, 8, 9, 10, 11, and 12 months). 16S rRNA Next Generation Sequencing (NGS) and LC-MS/MS techniques were used to analyze the microbial diversity and identify taste-enhancing peptides. Descriptive sensory analysis was performed on the extracts of the 108 Pla-ra samples mixed in a model broth. Koku perception and saltiness-enhancing attributes were clearly perceived and dominant in all samples, even though glutamyl peptides, including γ-Glu-Val-Gly, were found at subthreshold levels. The samples from mixed fish and Mor fish fermented with roasted ground rice and rice bran for 12 months had the most typical Pla-ra odors and tastes and had high taste-enhancing activities. NGS analysis revealed the presence of bacteria containing a large number of protease and aminopeptidase genes in the samples. Bacillus spp., Gallicola spp., and Proteiniclasticum spp. correlated well with the generation of glutamyl and arginyl peptides and typical odors in the samples. These results confirmed the typical sensory quality of Pla-ra depended on protein sources, carbohydrate sources, and bacteria communities. Further optimization of the microbial composition found could lead to the development of starter cultures to control and promote flavor development in fermented fish products.

Fermentation Technology and Functional Foods.

Food is an integral part of our civilization. It is a cultural phenomenon that, while having evolved, is associated with societal traditions and identity. This work analyzes studies conducted to highlight the health properties of the most common ethnic foods. Although these foods were originally created from the need to preserve perishable produce, presently, we know that the fermentation process makes them nutritionally more complete. The basis of these transformations lies in that vast range of prokaryotic and eukaryotic microorganisms that, similar to small biochemical factories, can transform the initial nutrients into metabolically more active biomolecules through fermentation. Although naturally occurring microbes work together for mutual benefit, environmental conditions enhance or inhibit their development. Starting from a selection of microorganisms naturally present on a substrate, we attempt to select the most suitable species to obtain a fermented food with the best nutritional qualities and the richest in nutraceuticals.

Traditional Bulgarian Fermented Foods as a Source of Beneficial Lactic Acid Bacteria.

BACKGROUND: Traditional Bulgarian fermented foods are prominent for their uniqueness of local ingredients, production methods, and endemic microbial species. The present research investigated the diversity and beneficial biological potential of lactic acid bacteria (LAB) isolated from various types of unique Bulgarian fermented foods. METHODS: Species identification was performed via 16S rDNA sequencing. Biological activity was evaluated by determining antibacterial activity (via agar well diffusion assay), H2O2 production, spectrophotometrically determined auto- and co-aggregation, microbial adhesion to hydrocarbon, and biofilm formation. The biosafety of the isolated lactic acid bacteria was established based on hemolytic activity and phenotypic and genotypic antibiotic susceptibility. RESULTS: Forty-five strains were isolated from fermented foods (sauerkraut, fermented green tomatoes, fermented cucumbers, kefir, white cheese, and Izvara (curdled milk)). Five species were detected: Lactiplantibacillus plantarum, Levilactobacillus koreensis, Levilactobacillus brevis, Lactobacillus helveticus, and Levilactobacillus yonginensis. The most prominent species was L. plantarum, at 47%. For the first time, L. koreensis and L. yonginensis, isolated from unique Bulgarian fermented foods, are reported in this study. The antibacterial effect of the cell-free supernatants was evaluated. An antagonistic effect was observed against Escherichia coli (57%) and Salmonella enterica subsp. enterica serotype Enteritidis (19%) for several L. plantarum strains. Only one L. brevis (Sauerkraut, S15) strain showed activity against E. coli. The best autoaggregation ability at hour 4 was observed for L. koreensis (fermented cucumbers, FC4) (48%) and L. brevis S2 (44%). The highest percentage of co-aggregation with Candida albicans, at hou 4 in the experiments, was observed for strains L. koreensis (fermented green tomato, FGT1) (70%), L. plantarum strains S2 (54%), S13 (51%), and S6 (50%), while at hour 24 for strains L. koreensis FGT1 (95%), L. brevis (Kefir, K7) (89%), L. plantarum S2 (72%), and L. koreensis FC2 (70%). Seven of the isolated LAB strains showed hydrophobicity above 40%. Our results showed that the ability of biofilm formation is strain-dependent. No hemolytic activity was detected. The antibiotic resistance to 10 antibiotics from different groups was tested phenotypically and genotypically. No amplification products were observed in any strains, confirming that the isolates did not carry antibiotic-resistance genes. CONCLUSIONS: Traditional fermented Bulgarian foods can be considered functional foods and beneficial LAB sources.

A combination of omics-based analyses to elucidate the effect of NaCl concentrations on the metabolites and microbial dynamics during the ripening fermentation of Pixian-Douban.

The study investigated the effect of different sodium chloride (NaCl) concentrations (10%, 15%, and 20%) on the ripening fermentation of Pixian-Douban, a traditional fermented condiment. The results showed that NaCl affected the dynamics of physicochemical parameters, volatile components, fatty acids, amino metabolites, organic acids, and microbial composition, and their dynamic modes were different. After 253 days fermentation, the 10% NaCl Pixian-Douban had significantly (p < 0.05) higher levels of total organic acids (20,308.25 mg/kg), amino metabolites (28,144.96 mg/kg), and volatiles (3.36 mg/kg) compared to 15% and 20% NaCl Pixian-Douban. Notably, the possible health risk associated with high concentration of biogenic amines in 10% NaCl Pixian-Douban is of concern. Moreover, correlation analyses indicated that the effect of NaCl on the quality of Pixian-Douban may be mainly related to bacteria. This study deepens the knowledge about the role of NaCl in ripening fermentation of Pixian-Douban and contributes to develop low-NaCl Pixian-Douban product.

Maternal fermented food intake and infant neurodevelopment: The Japan Environment and Children's Study.

BACKGROUND AND OBJECTIVES: Fermented foods play an important role in establishing intestinal bacterial flora, and the composition of the intestinal bacterial flora might be associated with neurodevelopment. This study investigated the association between maternal intake of fermented foods during pregnancy and early neuro-development in offspring. METHODS AND STUDY DESIGN: Data were analyzed for 73,522 pregnant women participating in the Japan Environment and Children's Study. Their intake of four common fermented foods during pregnancy was assessed using a semi-quantitative FFQ. Neurodevelopment in their infants at 1 year of age was estimated using the Ages and Stages Questionnaires. RESULTS: Multivariable logistic regression analysis showed that maternal intake of miso soup and fermented soybeans was each associated with a significantly reduced risk of delay in infant communication skills. Maternal intake of fermented soybeans and cheese was each associated with a significantly reduced risk of delay in fine motor skills in the third and fourth quartiles. For problem-solving, preventive associations were observed with maternal intake of fermented soybeans in the second and third quartiles and with maternal intake of cheese in the third and fourth quartiles. Maternal intake of yogurt was associated with a significantly reduced risk of delay in personal-social skills in the third and fourth quartiles, while that of cheese was associated with a reduced risk in the third quartile. No reductions in risk were observed for gross motor skills. CONCLUSIONS: Our results suggest that fermented food intake during pregnancy may have beneficial associations with several areas of psychomotor development in children.

Lactiplantibacillus paraxiangfangensis sp. nov., isolated from traditional Chinese pickle.

Three Gram-stain-positive bacterial strains (designated 231-9T, 142-6 and 463-4) were isolated from traditional Chinese pickle, and were characterized using a polyphasic taxonomic approach. Results of 16S rRNA gene sequence analysis indicated that strains 231-9T, 142-6 and 463-4 were phylogenetically related to the type strains of Lactiplantibacillus xiangfangensis, Lactiplantibacillus garii, Lactiplantibacillus carotarum, Lactiplantibacillus plajomi and Lactiplantibacillus modestisalitolerans, having 98.6-99.9 % 16S rRNA gene sequence similarities. Strains 231-9T, 142-6 and 463-4 were most closely related to the type strain of L. xiangfangensis, having 99.9 % 16S rRNA gene, 95.6 % pheS, 99.4 % rpoA and 98.2 % concatenated pheS and rpoA sequence similarities. Relatively low pheS (95.6 %) sequence similarity indicated that strain 231-9T should be further identified. Strain 231-9T shared 99.7-99.9 % average nucleotide identity (ANI) and 98.8-98.9 % digital DNA-DNA hybridization (dDDH) values with strains 142-6 and 463-4, indicating that they belonged to the same species. The ANI and dDDH values between strain 231-9T and L. xiangfangensis LMG 26013T were 92.4-92.9 and 49.6 %, respectively, less than the threshold for species demarcation (95-96% ANI and 70 % dDDH values, respectively), indicating that strains 231-9T, 142-6 and 463-4 represented a novel species within the genus Lactiplantibacillus. Acid production from d-ribose, d-adonitol, d-galactose and lactose, activity of ß-galactosidase and ß-glucosidase, Voges-Proskauer reaction, hydrolysis of hippurate, resistance to 5 µg ml-1 erythromycin, 100 µg ml-1 tetracycline hydrochloride, 50 µg ml-1 bacitracin, 300 µg ml-1 each of gentamicin sulphate, streptomycin sulphate and neomycin sulphate, tolerance to 6 % NaCl could distinguish strains 231-9T, 142-6 and 463-4 from L. xiangfangensis 3.1.1T. Based upon the data of polyphasic characterization obtained in the present study, a novel species, Lactiplantibacillus paraxiangfangensis sp. nov., is proposed and the type strain is 231-9T (=JCM 36258T=CCTCC AB 2023133T).

Characterization of the broad-spectrum antibacterial activity of bacteriocin-like inhibitory substance-producing probiotics isolated from fermented foods.

Antimicrobial peptides, such as bacteriocin, produced by probiotics have become a promising novel class of therapeutic agents for treating infectious diseases. Selected lactic acid bacteria (LAB) isolated from fermented foods with probiotic potential were evaluated for various tests, including exopolysaccharide production, antibiotic susceptibility, acid and bile tolerance, antibacterial activity, and cell adhesion and cytotoxicity to gastric cell lines. Six selected LAB strains maintained their high viability under gastrointestinal conditions, produced high exopolysaccharides, showed no or less cytotoxicity, and adhered successfully to gastric cells. Furthermore, three strains, Weissella confusa CYLB30, Lactiplantibacillus plantarum CYLB47, and Limosilactobacillus fermentum CYLB55, demonstrated a strong antibacterial effect against drug-resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica serovar Choleraesuis, Enterococcus faecium, and Staphylococcus aureus. Whole genome sequencing was performed on these three strains using the Nanopore platform; then, the results showed that all three strains did not harbor genes related to toxins, superantigens, and acquired antimicrobial resistance, in their genome. The bacteriocin gene cluster was found in CYLB47 genome, but not in CYLB30 and CYLB55 genomes. In SDS-PAGE, the extract of CYLB30 and CYLB47 bacteriocin-like inhibitory substance (BLIS) yielded a single band with a size of less than 10 kDa. These BLIS inhibited the growth and biofilm formation of drug-resistant P. aeruginosa and methicillin-resistant S. aureus (MRSA), causing membrane disruption and inhibiting adhesion ability to human skin HaCaT cells. Moreover, CYLB30 and CYLB47 BLIS rescued the larvae after being infected with P. aeruginosa and MRSA infections. In conclusion, CYLB30 and CYLB47 BLIS may be potential alternative treatment for multidrug-resistant bacteria infections.