Weissella paramesenteroides NRIC1542 inhibits dextran sodium sulfate-induced colitis in mice through regulating gut microbiota and SIRT1/NF-κB signaling pathway.

Inflammatory bowel disease (IBD) is a kind of recurrent inflammatory disorder of the intestinal tract. The purpose of this study was to investigate the effects of Weissella paramesenteroides NRIC1542 on colitis in mice. A colitis model was induced by adding 1.5% DSS to sterile distilled water for seven consecutive days. During this process, mice were administered different concentrations of W. paramesenteroides NRIC1542. Colitis was assessed by DAI, colon length and hematoxylin-eosin staining of colon sections. The expressions of NF-κB signaling proteins and the tight junction proteins ZO-1 and occludin were detected by western blotting, and the gut microbiota was analyzed by 16S rDNA. The results showed that W. paramesenteroides NRIC1542 significantly reduced the degree of pathological tissue damage and the levels of TNF-α and IL-1ß in colonic tissue, inhibiting the NF-κB signaling pathway and increasing the expression of SIRT1, ZO-1 and occludin. In addition, W. paramesenteroides NRIC1542 can modulate the structure of the gut microbiota, characterized by increased relative abundance of Muribaculaceae_unclassified, Paraprevotella, Prevotellaceae_UCG_001 and Roseburia, and decrease the relative abundance of Akkermansia and Alloprevotella induced by DSS. The above results suggested that W. paramesenteroides NRIC1542 can protect against DSS-induced colitis in mice through anti-inflammatory, intestinal barrier maintenance and flora modulation.

Comparative genomic analysis of Periweissella and the characterization of novel motile species.

The genus Periweissella was proposed as a novel genus in the Lactobacillaceae in 2022. However, the phylogenetic relationship between Periweissella and other heterofermentative lactobacilli, and the genetic and physiological properties of this genus remain unclear. This study aimed to determine the phylogenetic relationship between Periweissella and the two closest genera, Weissella and Furfurilactobacillus, by the phylogenetic analysis and calculation of (core gene) pairwise average amino acid identity. Targeted genomic analysis showed that fructose bisphosphate aldolase was only present in the genome of Pw. cryptocerci. Mannitol dehydrogenase was found in genomes of Pw. beninensis, Pw. fabaria, and Pw. fabalis. Untargeted genomic analysis identified the presence of flagellar genes in Periweissella but not in other closely related genera. Phenotypes related to carbohydrate fermentation and motility matched the genotypes. Motility genes were organized in a single operon and the proteins shared a high amino acid similarity in the genus Periweissella. The relatively low similarity of motility operons between Periweissella and other motile lactobacilli indicated the acquisition of motility by the ancestral species. Our findings facilitate the phylogenetic, genetic, and phenotypic understanding of the genus Periweissella.ImportanceThe genus Periweissella is a heterofermentative genus in the Lactobacillaceae which includes predominantly isolates from cocoa fermentations in tropical climates. Despite the relevance of the genus in food fermentations, genetic and physiological properties of the genus are poorly characterized and genome sequences became available only after 2020. This study characterized strains of the genus by functional genomic analysis, and by determination of metabolic and physiological traits. Phylogenetic analysis revealed that Periweissella is the evolutionary link between rod-shaped heterofermentative lactobacilli and the coccoid Leuconostoc clade with the genera Weissella and Furfurilactobacillus as closest relatives. Periweissella is the only heterofermentative genus in the Lactobacillaceae which comprises predominantly motile strains. The genomic, physiological, and metabolic characterization of Periweissella may facilitate the potential use of strains of the genus as starter culture in traditional or novel food fermentations.

HigBA toxin-antitoxin system of Weissella cibaria is involved in response to the bile salt stress.

BACKGROUND: Toxin-antitoxin (TA) systems are prevalent adaptive genetic elements in bacterial genomes, which can respond to environmental stress. While, few studies have addressed TA systems in probiotics and their roles in the adaptation to gastrointestinal transit (GIT) environments. RESULTS: The Weissella cibaria 018 could survive in pH 3.0-5.0 and 0.5-3.0 g L-1 bile salt, and its HigBA system responded to the bile salt stress, but not to acid stress. The toxin protein HigB and its cognate antitoxin protein HigA had 85.1% and 100% similarity with those of Lactobacillus plantarum, respectively, and they formed the stable tetramer HigB-(HigA)2 -HigB structure in W. cibaria 018. When exposed to 1.5-3.0 g L-1 bile salt, the transcriptions of higB and higA were up-regulated with 4.39-19.29 and 5.94-30.91 folds, respectively. Meanwhile, W. cibaria 018 gathered into a mass with 48.07% survival rate and its persister cells were found to increase 8.21% under 3.0 g L-1 bile salt. CONCLUSION: The HigBA TA system of W. cibaria 018 responded to the bile salt stress, but not to acid stress, which might offer novel perspectives to understand the tolerant mechanism of probiotics to GIT environment. © 2022 Society of Chemical Industry.

Biodegradation of chlorpyrifos by a Weissella confusa strain and evaluation of some probiotic traits.

Pesticides play an important role in agriculture; however, their excessive use causes several problems such as pollution of ecosystems and risks to human health. The presence of microorganisms able to degrade these pollutants can reduce their negative effect. The objective of this study was to test the capacity of Weissella confusa Lb.Con to tolerate or to degrade the chlorpyrifos pesticide. The results showed the capacity of the strain to tolerate a concentration of 200 µg/ml of chlorpyrifos. The strain Lb.Con has a remarkable capacity to grow in glucose-free MRS medium which contains different concentrations of chlorpyrifos. HPLC analysis showed that this strain was able to remove about 25% of chlorpyrifos. The evaluation of some probiotic properties showed that the strain Lb.Con had a remarkable resistance to the gastrointestinal conditions and a good antibacterial activity towards the pathogenic bacteria. The probiotic potential was evaluated to verify the possible use of W. confusa Lb.Con to detoxify harmful chlorpyrifos contained in food.

Brewers' spent grain as substrate for dextran biosynthesis by Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16.

BACKGROUND: Lactic acid bacteria can synthesize dextran and oligosaccharides with different functionality, depending on the strain and fermentation conditions. As natural structure-forming agent, dextran has proven useful as food additive, improving the properties of several raw materials with poor technological quality, such as cereal by-products, fiber-and protein-rich matrices, enabling their use in food applications. In this study, we assessed dextran biosynthesis in situ during fermentation of brewers´ spent grain (BSG), the main by-product of beer brewing industry, with Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16. The starters performance and the primary metabolites formed during 24 h of fermentation with and without 4% sucrose (w/w) were followed. RESULTS: The starters showed similar growth and acidification kinetics, but different sugar utilization, especially in presence of sucrose. Viscosity increase in fermented BSG containing sucrose occurred first after 10 h, and it kept increasing until 24 h concomitantly with dextran formation. Dextran content after 24 h was approximately 1% on the total weight of the BSG. Oligosaccharides with different degree of polymerization were formed together with dextran from 10 to 24 h. Three dextransucrase genes were identified in L. pseudomesenteroides DSM20193, one of which was significantly upregulated and remained active throughout the fermentation time. One dextransucrase gene was identified in W. confusa A16 also showing a typical induction profile, with highest upregulation at 10 h. CONCLUSIONS: Selected lactic acid bacteria starters produced significant amount of dextran in brewers' spent grain while forming oligosaccharides with different degree of polymerization. Putative dextransucrase genes identified in the starters showed a typical induction profile. Formation of dextran and oligosaccharides in BSG during lactic acid bacteria fermentation can be tailored to achieve specific technological properties of this raw material, contributing to its reintegration into the food chain.

Regioselective asymmetric bioreduction of trans-4-phenylbut-3-en-2-one by whole-cell of Weissella cibaria N9 biocatalyst.

There is a considerable interest in the asymmetric production of chiral allylic alcohols, the main building blocks of many functional molecules. The asymmetric reduction of α,ß-unsaturated ketones is difficult with traditional chemical protocols in a regioselective and stereoselective manner. In this study, the reductive capacity of whole cell of Leuconostoc mesenteroides N6, Weissella paramesenteroides N7, Weissella cibaria N9, and Leuconostoc pseudomesenteroides N13 was investigated as whole-cell biocatalysts in the enantioselective reduction of (E)-4-phenylbut-3-en-2-one (1). The biocatalytic reduction of 1 to (S,E)-4-phenylbut-3-en-2-ol ((S,E)-2) using the whole cell of W. cibaria N9 isolated from Turkish sourdough was developed in a regioselective fashion, occurring with excellent conversion and recovering the product in good yield. In biocatalytic reduction reactions, the conversion of the substrate and the enantiomeric excess (ee) of the product are significantly affected by optimization parameters such as temperature, agitation rate, pH, and incubation time. Effects of these parameters on ee and conversion were investigated comprehensively. In addition, to our knowledge, this is the first report on production of (S,E)-2 using whole-cell biocatalyst in excellent yield, conversion with enantiopure form and at gram scale. These findings pave the way for the use of whole cell of W. cibaria N9 for challenging higher substrate concentrations of different α,ß-unsaturated ketones for regioselective reduction at industrial scale.

Synthesis of silver nanoparticles prepared with a dextran-type exopolysaccharide from Weissella cibaria MED17 with antimicrobial functions.

Microbial polysaccharides can find distinct applications as stabilizer agents including synthesis of nanoparticles. In this study, a dextran-type exopolysaccharide (EPS) was used as the stabilizer agent for the green synthesis of silver nanoparticles (AgNPs-Dex) with antimicrobial characteristics. UV-vis spectroscopy analysis was used to test the formation of AgNPs-Dex. The uniform morphology at around 10 nm size was observed for AgNPs-Dex by TEM analysis and importantly EDX analysis demonstrated the embedment of Ag+ ions within dextran as the stabilizer agent. XRD analysis confirmed the crystalline nature of AgNPs-Dex and FTIR analysis demonstrated the interactions of dextran functional groups with silver. DSC and TGA analysis showed the alteration in the thermal stability of AgNPs-Dex compared to the stabilizer dextran. The antibacterial and antifungal activities of AgNPs-Dex were determined against food originated pathogenic bacteria and fungi and important inhibition levels were observed at 1 mg ml-1 concentration of AgNPs-Dex and this activity was observed to be concentration dependent.

A polyphasic approach to characterize Weissella cibaria and Weissella confusa strains.

AIM: To study Weissella cibaria and Weissella confusa strains, lactic acid bacteria (LAB) members naturally present in food products, but not yet included in Qualified Presumption of Safety (QPS) list of European Food Safety Authority (EFSA). METHODS AND RESULTS: We carried out a comparative genome analysis of 23 sequenced W. cibaria and 7 W. confusa genomes, in parallel with a physiological and functional characterization of several strains previously isolated from sourdough-like maize bran fermentation. The genome analysis revealed the absence of dedicated pathogenicity factors. Some putative virulence genes found in Weissella genomes were also present in other LAB strains, considered safe by EFSA and commonly used as probiotics. The physiological tests carried out on our strains corroborated the genomic results. Moreover, the following functional traits of interest to application in the food sector were identified: the majority of tested strains displayed high acidification rate, high reducing ability, production of exopolysaccharides (EPS), arabinoxylan degradation ability, growth in the presence of fructo-oligosaccharides (FOS), bile and gastric juice tolerance, and antifungal activity. CONCLUSIONS: These results provide evidence for the possible use of selected strains of W. cibaria and W. confusa in the food sector. SIGNIFICANCE AND IMPACT OF THE STUDY: This polyphasic study adds to the body of knowledge on the functional and applicable characteristics of these controversial species of LAB. This knowledge contributes to design new selected cultures included in the QPS list required for food applications.

Synbiotic fermented soymilk with Weissella cibaria FB069 and xylooligosaccharides prevents proliferation in human colon cancer cells.

AIM: Studies on the anticancer effects of synbiotic fermented soymilk are rare. The aim of the present study was to evaluate the effect of synbiotic fermented soymilk supplemented with xylooligosaccharides and inoculated with Weissella cibaria FB069 (FSMXW) in the proliferation of colon cancer cell and compare it with the effect of soymilk inoculated with Lactobacillus rhamnosus GG (LGG). METHODS AND RESULTS: Both FB069 and LGG were able to grow in soy-based products and rapidly reduce their pH as a result of fermentation. The addition of XOS significantly enhanced the acidification rate, viscosity and total cell concentration in fermented soymilk inoculated with W. cibaria FB069. However, the same effect was not observed following inoculation with LGG. Moreover, the synbiotic FSMXW showed higher dextran, folate, GABA and aglycone content. FSMXW inhibited the proliferation of Caco-2 and HCT116 cell lines, by reducing the transcription of MD2, TLR4, MyD88, and NF-κb. CONCLUSIONS: The synbiotic soymilk containing XOS and W. cibaria FB069 increase nutrient and functional compounds through fermentation process. SIGNIFICANCE AND IMPACT OF THE STUDY: Our finding suggests that W. cibaria and XOS can be potentially employed in developing functional foods and health-related products.

Persistence of a mixed lactic acid bacterial starter culture during lysine fortification of sourdough breads by addition of pistachio powder.

Pistachio powder was added to flour or semolina to evaluate its contribution to increase the amount of lysine in bread. Bread production was carried out by sourdough technology using a selected 3-species (Lactobacillus sanfranciscensis/Leuconostoc citreum/Weissella cibaria) lactic acid bacterial (LAB) starter culture. All sourdoughs were subjected to a long-time fermentation (21 h) and showed levels of LAB around 109 CFU/g, indicating the suitability of pistachio powder for lactic fermentation. Yeasts were also detected, in particular in semolina trials. MiSeq Illumina technology was applied to investigate the bacterial composition of sourdoughs evidencing a different distribution of LAB species among the trials with Lactobacillus as major LAB group in almost all sourdoughs. Physicochemical parameters were comparable among the trials. After baking, pistachio powder was found not to influence the height of the breads, but pistachio breads were more firm than control breads. Color of the breads, void fraction and cell density, were influenced by pistachio powder. The amount of lysine increased consistently thanks to pistachio supplementation which also determined a higher presence of o-xylene, p-cymene and limonene and the appearance of α-pinene and 1-octen-3-ol in breads. Sensory tests showed the best appreciation scores for the breads produced with flour and pistachio powder.

Molecular analysis of the dominant lactic acid bacteria of chickpea liquid starters and doughs and propagation of chickpea sourdoughs with selected Weissella confusa.

Fermented chickpea liquid is used as a leavening agent in chickpea bread production. In the present study, traditional chickpea liquid starter and dough samples were collected from bakeries in Turkey and microbiologically investigated. Culture-independent analysis for microbiota diversity, performed by MiSeq Illumina, identified Clostridium perfringens as major group in all samples, while Weissella spp. Dominated LAB community. A culture-dependent methodology was applied and 141 isolates were confirmed to be members of the LAB group based on 16s rRNA gene sequence analysis. In particular, 11 different LAB species were identified confirming the high frequency of isolation of weissellas, since Weissella confusa and Weissella cibaria constituted 47.8 and 12.4%, respectively, of total LAB isolated. The other species were Enterococcus faecium, Enterococcus lactis, Lactobacillus brevis, Lactobacillus plantarum, Leuconostoc mesenteroides, Leuconostoc mesenteroides subsp. Dextranium, Pediococcus acidilactici, Pediococcus pentosaceus and Streptococcus lutetiensis. Due to high frequency of isolation, W. confusa strains were investigated at technological level and W. confusa RL1139 was used as mono-culture starter in the experimental chickpea sourdough production. Chemical and microbiological properties, as well as volatile organic compounds (VOCs) of the chickpea liquid starters and doughs were subjected to a multivariate analysis. Control and W. confusa inoculated chickpea liquid starter and dough samples were close to each other in terms of some characteristics related to chemical, microbiological and VOCs profile, but the inoculated sourdough showed a higher generation of certain VOCs, like butanoic acid (81.52%) and ethyl acetate (8.15%) than control sourdough. This is important in order to maintain typical characteristics of the traditional chickpea dough, but at the same time improving the aroma profile. This work demonstrated that W. confusa RL1139 can be applied at large scale production level without compromising the typical characteristics of the final product.

Viability of Staphylococcus aureus and expression of its toxins (SEC and TSST-1) in cheeses using Lactobacillus rhamnosus D1 or Weissella paramesenteroides GIR16L4 or both as starter cultures.

Staphylococcus aureus is one of the main causative agents of food poisoning. This bacterium is an important component of cheese microbiota and plays an important role in foodborne diseases. Another important component of the microbiota is the lactic acid bacterium, which actively participates in processes that define the physicochemical, sensorial, and microbiological features of cheese. Of the various microbiological interactions in cheese, the interaction between lactic acid bacteria and Staph. aureus is most relevant. To this end, we evaluated the viability of Staph. aureus strains and the expression of their enterotoxins in cheeses produced experimentally, using Weissella paramesenteroides GIR16L4 or Lactobacillus rhamnosus D1 or both as starter cultures. Over 7 d, we observed that the presence of lactic acid bacteria did not impair Staph. aureus growth. However, via qPCR we observed a change in the gene expression of staphylococcal enterotoxins, suggesting that molecular communication exists between Staph. aureus strains and lactic acid bacteria in cheese.

Potential prebiotic effect of a long-chain dextran produced by Weissella cibaria: an in vitro evaluation.

Dextrans are homopolysaccharides of D-glucose units produced by lactic acid bacteria. They have several technological applications and potential utilisation in positively modulating gut microbiota is attracting increasing attention. Whereas the prebiotic activity of low polymerisation degree (DP) dextrans has been established, high DP dextrans still deserve deeper investigation. In the present study, a long linear chain dextran produced by Weissella cibaria was compared to inulin with regards to the growth of specific health-related taxa and to the production of organic acids in pH-controlled batch cultures of intestinal microbiota. qPCR quantification of Lactobacillus, Bifidobacterium, Prevotella, Bacteroides fragilis, and Faecalibacterium prausnitzii revealed differences in their relative abundance, depending on the carbon source, that reflected the pattern of fermentation products determined by HPLC. Dextran mainly enhanced the relative amount of Prevotella and Bacteroides, consistently with a favourable acetate-propionate ratio suggesting a promising utilisation as functional ingredient in the food industry.

The response surface optimization of exopolysaccharide produced by Weissella confusa XG-3 and its rheological property.

The response surface methodology (RSM) was used to optimize the exopolysaccharide (EPS) production by a lactic acid bacteria (LAB) Weissella confusa XG-3. Two-level factorial design screened three significantly influencing factors sucrose, initial pH and sodium acetate. Central composite design (CCD) predicted under the condition of sucrose 80.1 g L-1, initial pH 5.8 and sodium acetate 3.7 g L-1, the maximal EPS yield obtained a 2.9-fold increase, reaching 97.5 ± 1.1 g L-1. This maximal value was far exceeding EPS production by other W. confusa species strains reported so far. The results suggested that W. confusa XG-3 had a potential for large-scale EPS production. The rheological properties of XG-3 EPS was further investigated. It was a typical non-Newtonian fluid, exhibiting pseudo-plastic behavior. The EPS concentration and temperature exerted positive and negative impact on apparent viscosity, respectively. The XG-3 EPS maintained relatively higher viscosity at moderate pH (6-8). The intrinsic viscosity [η] was 409.7 (25 °C) and 201.7 (35 °C), which was relevant to temperature but irrelevant to EPS concentration. This EPS efficiently coagulated sucrose-supplemented milk in a concentration-dependent manner. These results indicated that XG-3 EPS had an applicable potential in food processing fields especially dairy products.

Dynamics and species diversity of lactic acid bacteria involved in the spontaneous fermentation of various palm tree saps during palm wine tapping in Côte d'Ivoire.

To document and speed up research on the usefulness and selection of potential health-promoting bacterial starter cultures from unexplored fermented saps of various palm species in Côte d'Ivoire, benchmark tapping processes were successfully developed and implemented at field level. Therefore, spontaneously fermented saps of three palm species (Elaeis guineensis, Raphia hookeri, Borassus aethiopum) were collected throughout tapping process and lactic acid bacteria (LAB) diversity and dynamics were studied through a multiphasic approach. Overall microbiological analysis revealed a LAB species diversity throughout tapping process. LAB isolates belonged to two main (GTG)5-PCR clusters, namely Fructobacillus durionis (40.33%) and Leuconostoc mesenteroides (45.66%), with Leuconostoc pseudomesenteroides, Lactobacillus paracasei, Lactobacillus fermentum Weissella cibaria, Enterococcus casseliflavus and Lactococcus lactis occurring occasionally. LAB diversity was higher in fermented saps from E. guineensis (8 species) than those of R. hookeri (5 species) and B. aethiopum (3 species). Dynamic study revealed that F. durionis and L. mesenteroides dominated the fermentations from the beginning until the end of tapping process in all palm wine types. But the earlier stages of the process were also populated by some species like W. cibaria, L. pseudomesenteroides and L. fermentum, which population decreased or disappeared after some days. Also, species of Enterococcus and Lactococcus genera were sporadically detected uniquely in sap from E. guineensis. This study is the first to investigate extensively the LAB diversity and dynamics throughout palm trees tapping process in Côte d'Ivoire and is relevant for future selection of health promoting bacteria.

Anti-bacterial susceptibility profiling of Weissella confusa DD_A7 against the multidrug-resistant ESBL-positive E. coli.

Extended-spectrum ß-lactamase (ESBL) positive bacteria are emerging pathogens causing disease like sepsis. Diseases caused by these organisms have become a challenge; because these organisms are getting resistance against almost all the recommended antibiotics used for its treatment. In the present study, in vitro antimicrobial effects of kimchi isolate Weissella confusa (DD_A7) has shown the ability to trigger an oxidative attack and limits the growth of multidrug-resistant (MDR) ESBL positive E. coli bacteria. The dose-dependent and time-dependent potential of cell-free culture supernatant (CFCS) were evaluated on the exposure of targeted pathogenic bacteria and has shown the maximum cell death upon treatment. Fluorescence and scanning electron microscopic analysis have confirmed the potential of CFCS to damage the cell membrane of the pathogenic bacteria. Moreover, in the study, we have also shown the capability of DD-A7 to reduce inflammatory cytokines in the host cells. Nevertheless, our study has revealed the prophylactic activity of DD_A7 against the invasion of pathogenic bacteria ex-vivo and possesses the non-hemolytic activity on mouse blood cells. Taken together, the present study successfully describes DD_A7 as a natural and alternative prophylactic agent against the ESBL-positive E. coli bacteria.

Isolation and characterization of high exopolysaccharide-producing Weissella confusa VP30 from young children's feces.

BACKGROUND: Lactic acid bacteria (LAB) are known to have a significant ability to colonize the human intestinal tract and adhere to the surface of intestinal epithelial cells. Among the various lactic acid bacteria, exopolysaccharide (EPS) producing strains are known to provide a variety of health benefits for their hosts (e.g. anti-inflammatory, antioxidant, antitumor and stress tolerant effects). Recently, EPSs and EPS-producing lactic acid cultures have gained interest within the food industry and are playing important roles as biothickeners and texturizing agents due to their hydrocolloidal nature. In this study, 156 lactic acid bacterial strains isolated from fecal samples of healthy young children were screened and evaluated for active EPS-production capability. RESULTS: Among the various human origin lactic acid flora isolated, Weissella confusa VP30 showed the highest EPS productivity and its EPS producing properties were characterized under various cultural conditions in this research. To document the safety of W. confusa VP30, antibiotic resistance, hemolytic, and ammonia production properties were evaluated in addition. No significant negative results were observed. The maximum EPS production by W. confusa VP30 was 59.99 ± 0.91 g/l after 48 h of cultivation in media containing 10% sucrose, far exceeding EPS production by other bacterial strains reported elsewhere. Based on gel permeation chromatography (GPC), the molecular weight of EPS produced by W. confusa VP30 was 3.8 × 106 Da. Structural analysis of the released EPS fraction by 13C and 1H nuclear magnetic resonance (NMR) spectroscopy revealed that W. confusa VP30 can produce dextran with glucose units linked with 96.5% α (1 → 6) glycosidic bonds and 3.5% α (1 → 3) branches. CONCLUSION: The high EPS production capability and safety of W. confusa VP30 justify food industry consideration of this cell strain for further evaluation and potential industrial use.

Development of a System of High Ornithine and Citrulline Production by a Plant-Derived Lactic Acid Bacterium, Weissella confusa K-28.

As a bacterium used in industry for production of several amino acids, an endotoxin-free Corynebacterium (C.) glutamicum is well known. However, it is also true that the endotoxin-producing other Corynebacterium species is present. An aim of this study is to obtain a lactic acid bacterium (LAB) that produces ornithine and citrulline at high levels. We successfully isolated a strain, designated K-28, and identified it as Weissella (W.) confusa. The production of ornithine and citrulline by K-28 was 18 ± 1 and 10 ± 2 g/L, respectively, with a 100 ± 9% conversion rate when arginine was continuously fed into a jar fermenter. Although the ornithine high production using C. glutamicum is industrially present, the strains have been genetically modified. In that connection, the wild-type of C. glutamicum produces only 0.5 g/L ornithine, indicating that W. confusa K-28 is superior to C. glutamicum to use a probiotic microorganism. We confirmed that W. confusa K-28 harbors an arginine deiminase (ADI) gene cluster, wkaABDCR. The production of ornithine and the expression of these genes significantly decreased under the aerobic condition rather than anaerobic one. The expression level of the five genes did not differ with or without arginine, suggesting that the production of amino acids in the K-28 strain was not induced by exogenous arginine.

Characterization of cottage cheese using Weissella cibaria D30: Physicochemical, antioxidant, and antilisterial properties.

This study aimed to evaluate the potential of Weissella cibaria D30 as an adjunct culture in cottage cheese, including an assessment of antioxidant, antilisterial, and compositional parameters. Cottage cheese samples were manufactured using a commercial starter culture and probiotic strains Lactobacillus rhamnosus GG (GG) or W. cibaria D30 (W) and without probiotic (control). Samples were stored at 4 ± 1°C for 28 d. Bacterial cell counts (log cfu/g) of control, GG, and W samples were counted at 0, 7, 14, 21, and 28 d. Counts of W. cibaria D30 in the W samples remained at 6.85 log cfu/g after 28 d. Total solids, fat, protein, ash, and pH were measured and no significant differences were observed in compositional parameters or pH after 28 d of storage in all cheeses except those inoculated to Listeria monocytogenes. To measure the antilisterial effect, Listeria monocytogenes was inoculated into the cottage cheese samples and bacterial cell counts were obtained at 0, 6, 12, 24, 48, 72, 96, 120, and 144 h. Listeria monocytogenes counts were less than the analytical limit of detection (<10 cfu/g) in the inoculated GG and W samples, whereas the counts of L. monocytogenes in the inoculated control sample remained at 3.0 log cfu/g after 144 h. We used the DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging activity assays to assess antioxidant activity: GG and W samples exhibited significant increases in antioxidant activity compared with the control sample. These results indicate that W. cibaria D30 has potential as an adjunct culture in the dairy industry.

Laxative effects of triple fermented barley extracts (FBe) on loperamide (LP)-induced constipation in rats.

BACKGROUND: Constipation, a common health problem, causes discomfort and affects the quality of life. This study intended to evaluate the potential laxative effect of triple fermented barley (Hordeum vulgare L.) extract (FBe), produced by saccharification, Saccharomyces cerevisiae, and Weissella cibaria, on loperamide (LP)-induced constipation in Sprague-Dawley (SD) rats, a well-established animal model of spastic constipation. METHODS: Spastic constipation was induced via oral treatment with LP (3 mg/kg) for 6 days 1 h before the administration of each test compound. Similarly, FBe (100, 200 and 300 mg/kg) was orally administered to rats once a day for 6 days. The changes in number, weight, and water content of fecal, motility ratio, colonic mucosa histology, and fecal mucous contents were recorded. The laxative properties of FBe were compared with those of a cathartic stimulant, sodium picosulfate. A total of 48 (8 rats in 6 groups) healthy male rats were selected and following 10 days of acclimatization. Fecal pellets were collected one day before administration of the first dose and starting from immediately after the fourth administration for a duration of 24 h. Charcoal transfer was conducted after the sixth and final administration of the test compounds. RESULTS: In the present study, oral administration of 100-300 mg/kg of FBe exhibited promising laxative properties including intestinal charcoal transit ratio, thicknesses and mucous producing goblet cells of colonic mucosa with decreases of fecal pellet numbers and mean diameters remained in the lumen of colon, mediated by increases in gastrointestinal motility. CONCLUSION: Therefore, FBe might act as a promising laxative agent and functional food ingredient to cure spastic constipation, with less toxicity observed at a dose of 100 mg/kg.