Antiseptic Efficacy of A Soap Made from Biosurfactants Isolated from Bacillus and Lactobacillus against Pathogenic Bacteria

The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological techniques (30 Bacillus and 30 Lactobacillus) and the ability to produce biosurfactants was demonstrated by a hydrocarbon emulsification index (E24). The emulsification indexes (E24) varied from 9% to 100% for Bacillus and from 33% to 100% for Lactobacillus as well. The antagonistic assay showed that biosurfactants were able to inhibit the formation of biofilms and growth of pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhirium, Shigella boydii and Proteus mirabilis. The biosurfactant consortium (BioC) from Bacillus consortium and from Lactobacillus was able to inhibit biofilm formation and the pathogens growth. The BioC was stable to alkaline pH and the temperatures stability of Biosurfactant was ranging from 50°C to 90°C. The soap was made by the cold saponification process using one biosurfactant consortium formulated. This soap has a pH of 10 and showed good cleaning power and good foam stability. Similarly, the soap showed good antiseptic power and disinfection power against all pathogens tested. Handwashing is critical to preventing disease transmission. The persistence of pathogens in waste water was evaluated. The BioS produced showed good disinfection power against all pathogens tested. The valor of reduction on the hands and in the waste water was significantly more than compared to the control soaps used. This soap could be used in the prevention, fighting, and treatment of bacterial and viral infections.

Impact of Dietary Lactobacillus plantarum Postbiotics on the Performance of Layer Hens under Heat Stress Conditions

This experiment was conducted to determine the performance of heat-stressed layers fed a diet containing the probiotic Lactobacillus plantarum RS5 or its products of fermentation (postbiotics). Twenty-week-old Isa White layers, were subdivided into six treatments of 32 individually caged birds. Half of the birds were reared under regular temperature conditions, while the other half was subjected to cyclic daily heat stress. Layers were offered one of three diets: 1) Control;2) Control + Lactobacillus plantarum RS5 probiotic;3) Control + Lactobacillus plantarum RS5 postbiotics. Birds were tested for performance and visceral organ development for 5 months. Heat stress negatively affected the birds’ feed intake, egg weight, shell weight percentage, Haugh unit, shell thickness, yolk color, body weight and spleen weight percentage. Postbiotics significantly increased egg production (p < 0.05) in comparison to the control and the probiotic fed group (94.8% vs 92.6% vs 93.1%, respectively). Birds under probiotic or postbiotic diet showed a significantly higher (p < 0.05) feed intake and egg weight, although the probiotic had a more pronounced and gradual effect. Specific gravity, yolk weight percentage and shell thickness didn’t show differences among dietary groups. The Haugh Unit was significantly higher (p < 0.05) in probiotic group which also showed a significantly lower yolk color index (p < 0.05). The different feed treatments did not impact the bird’s viscera weight percentage, except for the ileum that was significantly lower (p < 0.05) under postbiotic supplementation. Both probiotics and postbiotics could be used as a potential growth promoters and might alleviate heat stress impact in poultry industry.

没食子酸对植物乳杆菌Lactobacillus plantarum的抑制和促进生长

该文以微生物生长曲线、多酚浓度变化和培养液pH值变化为指标,研究了没食子酸(GallicAcid,GA)和表没食子儿茶素没食子酸酯(Epigallocatechin Gallate,EGCG)对植物乳杆菌CICC 6253生长的影响。结果表明GA和EGCG对植物乳杆菌生长的影响具有浓度依赖性,可表现出抑制和促进的双向调节作用,且二者的作用存在构效差异性。在GA和EGCG分别在5 mg/mL和7 mg/mL以上时,两者都抑制了植物乳杆菌的生长,而当GA和EGCG分别低于4 mg/mL和6 mg/mL时二者都促进了细胞的增殖,且随质量浓度增加其促进作用增大。GA可作为碳源被植物乳杆菌迅速利用,而EGCG(4 mg/mL)因其良好的细胞亲和性表现出显著的促进作用,高效地促进了植物乳杆菌细胞的增殖,菌落数在28h内由7.42lgCFU/mL增加到12.54lgCFU/mL,与空白对照组相比增加了2个数量级以上。本研究表明,GA和EGCG均表现出对植物乳杆菌的双向调节作用,其中EGCG表现出更佳的益生特性。本文研究结果可为GA和EGCG及类似食源性多酚在益生菌生长调节和相关食品研发中提供参考。

Demonstration of safety characteristics and effects on gut microbiota of Lactobacillus gasseri HMV18

Human normal flora is a source of probiotics.The safety characteristics of a specific isolate determine its application in foods or drugs.The food-borne-pathogen antagonist strain Lactobacillus gasseri HMV18 is one of the isolates from normal human flora.In this work,we assessed the in vitro pH tolerance,bile tolerance,biogenic amine production,mucin utilization,and safety of in vivo administration to mice to evaluate general health,organ-body weight index,organ histopathological change,whether L.gasseri HMV18 can colonize in the gut or modulate the gut microbiota after oral administration.The results suggest that L.gasseri HMV18 can tolerate pH 3 for 2 h,3%bile for 3 h,biogenic amine negative,mucin usage negative,does not encode verified toxins,and cause no visible change in mice's organs.L.gasseri HMV18 might not colonize in mice's gut,but can significantly affect the structure of gut microbiota.A bibliographical survey suggested that there were as few as 8 opportunistic infection cases from 1984 to 2022 and that the possibility for L.gasseri to cause infection is relatively low.Therefore,this work provides a basis for the foods or drugs application of L.gasseri HMV18 and gives a map of experiments for the safety assessment of probiotics.

Identification,Characterization,and Probiotic Potentials of Lactobacillus pentosus SF-1

In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in aquaculture.In the present study a strain of Lactobacillus pentosus,named as L.pentosus SF-1,was isolated from waters in aquaculture.The species identification of this strain was conducted by 16S rRNA sequence,and the physiological and biochemical characteristics of this strain were assessed.Furthermore,the virulence,antibiotic sensitivity,cell surface characteristics and acid/base-resistance of L.pentosus SF-1 were determined to evaluate the probiotic potentials of this strain.Specifically,L.pentosus SF-1 is sensitive to most common antibiotics,and no hemolysin was generated from it,indicating the safety of this strain to hosts.In addition,L.pentosus SF-1 was able to tolerate the artificial gastric juice at pH 3 for 4 h and the artificial intestinal fluid at pH 6.8 or 8.0 for 6 h.Moreover,the analysis of self-aggregation and the adhesion of L.pentosus SF-1 to organic solvents suggested a high potential of L.pentosus SF-1 to inhabit the hosts,which was confirmed by testing the colonization of L.pentosus SF-1 in germ-free zebrafish.Interestingly,L.pentosus SF-1 displayed a high bactericidal activity against several bacterial pathogens.Consistently,the incubation of L.pentosus SF-1 significantly promoted the expression of antimicrobial components in zebrafish,contributing to the protection of the fish from E.tarda infection in vivo.Taken together,the probiotic strain L.pentosus SF-1 could be applied as anti-infection reagent in aquaculture.

Effect of dietary supplement of inactivated Lactobacillus plantarum Ep-M 17 on growth performance,immune response,disease resistance,and intestinal microbiota in Penaeus vannamei

Our previous study found that feeding with Lactobacillus plantarum Ep-M17 could effectively affect the growth performance,immune response,and gut microbiota of Penaeus vannamei.However,high temperature and pressure during feed pelletizing is the main problem that can lead to a decrease in the activity of probiotics or cause their inactivation.Further investigation needs to investigate whether inactivated Ep-M17 can exert similar effects as live Ep-M17.Therefore,we evaluated the effects of inactivated L.plantarum Ep-M17 on growth performance,immune response,disease resistance,and gut microbiota in P.vannamei.Results show that adding inactivated Ep-M17 to the feed also promoted body weight gain and increased relative immune protection in shrimp.Also,histological examination revealed that the administration of inactivated Ep-M17 led to improvements in the density and distribution of microvilli in the intestines and enhancements in the abundance of B and R cells in the hepatopancreas.Additionally,the inactivated Ep-M17 supplementation resulted in increased activity levels of nutrient immune-related enzymes in both the shrimp hepatopancreas and intestines.Moreover,it stimulated the expression of Lvlec,PEN-3a,Crustin,LGBP,Lysozyme,and proPo genes in both the hepatopancreas and intestines.Furthermore,the inactivated Ep-M17 also increased bacterial diversity in the gut of shrimp and promoted the abundance of specific flora,facilitating the host organism’s metabolism and immunity to improve the disease resistance of shrimp.Therefore,supplementation of inactivated L.plantarum Ep-M17 in shrimp diets can exert similar effects as live L.plantarum Ep-M17 effectively improving growth performance,gut microbiota,immune response,and disease resistance in P.vannamei.

Lactobacillus plantarum AR495 improves stress-induced irritable bowel syndrome in rats by targeting gut microbiota and Mast cell-PAR2-TRPV1 signaling pathway

Probiotics have great potential in regulating intestinal pain.In this study,the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome(IBS)rats were studied.The results showed that tryptase released after mast cell activation and degranulation plays a key role in visceral pain,and L.plantarum AR495 reduced the stimulation of colonic mast cells and the expression of protease-activated receptor 2(PAR2)and TRPV1 in dorsal root ganglia.Research further showed that supplementation with L.plantarum AR495 increased the level of short-chain fatty acids(SCFAs)and enhanced the barrier function of the colon.In addition,the microbiota analysis of the colon indicated that L.plantarum AR495 promoted the proliferation of Bifidobacterium and inhibited the proliferation of Lachnospiraceae,which alleviated the imbalance of the intestinal microbiota caused by IBS to a certain extent.In total,L.plantarum AR495 might reduce visceral sensitivity through the Mast cell-PAR2-TRPV1 signaling pathway by maintaining the homeostasis of the intestinal barrier.

Effects of Lactobacillus paracasei N1115 on gut microbial imbalance and liver function in patients with hepatitis B-related cirrhosis

BACKGROUND Hepatitis B cirrhosis(HBC)is a chronic disease characterized by irreversible diffuse liver damage and aggravated by intestinal microbial imbalance and metabolic dysfunction.Although the relationship between certain single probiotics and HBC has been explored,the impact of the complex ready-to-eat Lactobacillus paracasei N1115(LP N1115)supplement on patients with HBC has not been determined.AIM To compare the changes in the microbiota,inflammatory factor levels,and liver function before and after probiotic treatment in HBC patients.METHODS This study included 160 HBC patients diagnosed at the General Hospital of Ningxia Medical University between October 2018 and December 2020.Patients were randomly divided into an intervention group that received LP N1115 supplementation and routine treatment and a control group that received routine treatment only.Fecal samples were collected at the onset and conclusion of the 12-wk intervention period.The structure of the intestinal microbiota and the levels of serological indicators,such as liver function and inflammatory factors,were assessed.RESULTS Following LP N1115 intervention,the intestinal microbial diversity significantly increased in the intervention group(P<0.05),and the structure of the intestinal microbiota was characterized by an increase in the proportions of probiotic microbes and a reduction in harmful bacteria.Additionally,the intervention group demonstrated notable improvements in liver function indices and significantly lower levels of inflammatory factors(P<0.05).CONCLUSION LP N1115 is a promising treatment for ameliorating intestinal microbial imbalance in HBC patients by modulating the structure of the intestinal microbiota,improving liver function,and reducing inflammatory factor levels.

Lactobacillus delbrueckii subsp.bulgaricus KSFY07对D-半乳糖诱导的氧化衰老小鼠运动能力的提升作用

该研究通过D-半乳糖建立小鼠衰老模型,观察了一株新发现的乳酸菌(Lactobacillus delbrueckii subsp.bulgaricus KSFY07,LDSBKSFY07)对衰老小鼠运动能力提升的作用并阐述了其作用机制。研究通过观察衰老小鼠跑步能力、游泳耐力、血液生化指标、组织病理学变化和mRNA表达变化、小鼠肠道内容物微生物变化来检测LDSBKSFY07提升小鼠运动能力的作用及机制。动物实验结果显示LDSBKSFY07(1.5×10^(9) CFU/kg BW灌胃)能够延长衰老小鼠的跑步时间和力竭游泳时间,降低衰老小鼠血清中的血尿素氮、血乳酸、丙二醛的水平,增加肝糖原、肌糖原的水平及超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶的酶活力。组织病理学观察提示LDSBKSFY07减轻了小鼠肝脏和肾脏肾组织的衰老损伤。qPCR结果显示LDSBKSFY07具备下调衰老小鼠肝脏、肾脏和骨骼肌组织诱导型一氧化氮合酶、肿瘤坏死因子α的mRNA表达和上调神经型一氧化氮合酶、Cu/Zn-SOD、Mn-SOD、过氧化氢酶表达的能力。另外,LDSBKSFY07还可以下调衰老小鼠骨骼肌组织的syncytin-1 mRNA表达。同时,LDSBKSFY07还增加了衰老小鼠肠道中厚壁菌门、乳酸杆菌、双歧杆菌的丰度和降低了拟杆菌门的丰度。而且,LDSBKSFY07对组织、血清和肠道菌群状态的调节作用优于维生素C(150 mg/kg BW灌胃)具有减缓小鼠衰老和提升其运动能力的效果。

干酪乳杆菌(Lactobacillus casei)FV006对发酵食品中生物胺的降解性能

为验证干酪乳杆菌(Lactobacillus casei)对生物胺的降解性能及潜在应用价值。本研究利用高效液相色谱法,探究该菌在液态培养条件下的降胺性能和应用于贵州6种市售发酵食品中的降胺效果。结果表明,在液态培养试验中该菌对组胺、亚精胺、苯乙胺、腐胺、尸胺、酪胺和色胺的降胺率分别为9.44%、23.39%、16.27%、13.68%、19.14%、18.16%和12.45%。此外,研究发现该菌对道菜中色胺的降胺率为56.68%;对豆瓣酱中尸胺、组胺和亚精胺的降胺率分别为68.06%、74.52%和85.82%;对酱油中色胺和尸胺的降胺率为66.75%%、81.53%;对泡菜中色胺的降胺率为45.74%;对鱼罐头中色胺、尸胺、组胺和亚精胺的降胺率分别为55.66%、63.92%、45.96%、52.62%;对香肠中色胺、组胺和亚精胺的降胺率分别为71.15%、56.26%、75.54%。研究还发现该菌既具有产生物胺的能力,也具有降解生物胺的能力,且对不同食品中同一种生物胺的降解具有差异性。本研究为干酪乳杆菌(Lactobacillus casei)在低胺发酵食品中的应用提供理论依据。

利用Lactobacillus kisonensis发酵藜麦-黑燕麦复合谷物富集多酚及黄酮的工艺优化

本研究利用植物乳杆菌(Lactobacillus kisonensis,JCM15041)发酵藜麦-黑燕麦复合谷物,以多酚和黄酮含量为响应值,在利用单因素实验明确原料比(藜麦:黑燕麦)、液料比、接种量和发酵时间等发酵工艺参数优化范围的基础上,利用响应面试验(四因素三水平),建立了可有效富集多酚及黄酮的藜麦-黑燕麦复合谷物优化发酵工艺。结果表明,原料比(藜麦:黑燕麦)、液料比、接种量和发酵时间对发酵后多酚和黄酮含量均有显著影响;藜麦-黑燕麦复合谷物发酵优化工艺条件为:原料比(藜麦:黑燕麦)1:3.4(g/g)、液料比7.5:1(mL/g)、接种量4.9%、发酵时间36.5 h,且在该发酵工艺条件下多酚和黄酮含量分别达到295.3和256.3 mg/100 g,均显著高于未发酵复合谷物(多酚和黄酮含量分别为216.2和202.4 mg/100 g)(P<0.05),也显著高于藜麦和黑燕麦单独发酵(多酚含量分别为256.7和255.3 mg/100 g;黄酮含量分别为209.0和163.3 mg/100 g)(P<0.05)。与单一谷物发酵相比,利用植物乳杆菌发酵藜麦-黑燕麦复合谷物可更有利于多酚和黄酮类功能性成分的富集,发酵产物可用于功能性谷物食品的开发。

Effect of fructooligosaccharides on the colonization of Lactobacillus rhamnosus AS 1.2466^(T) in the gut of mice

Lactobacillus rhamnosus and fructooligosaccharides(FOS)have been widely studied so far.However,the effects of L.rhamnosus on the intestinal microecological environment at the species level and the effect of different proportions of FOS on L.rhamnosus colonization in different parts of mice intestine are still unclear.The study results indicated that the specific bands of enterobacterial repetitive intergenic consensus polymerase chain reaction(ERIC-PCR)in the L.rhamnosus(LR)group significantly increased at 7 days.Although the number of bands was similar to the natural recovery(NR)group,the brightness of few bands significantly enhanced in the later stage of recovery.Besides,Southern-blot maps showed strong signals,indicating that the ERIC-PCR fingerprint could accurately reflect the changes in the mouse gut microbiota diversity.Further,the high-throughput results confirmed that the Lactobacillus and Akkermansia had different changes at different periods,but all of them showed an upward trend,while the Klebsiella were inhibited,thereby maintaining the intestinal microecology balance.Moreover,FOS exerted a positive effect on L.rhamnosus colonization in the gut.

Lactobacillus rhamnosus GR-1 attenuates foodborne Bacillus cereus-induced NLRP3 inflammasome activity in bovine mammary epithelial cells by protecting intercellular tight junctions

Background:Bacillus cereus is an important pathogen that causes human food poisoning,specifically diarrhea and vomiting.B.cereus can also induce mastitis in dairy cows and has a strong survival ability in milk,as it cannot be inactivated by high-temperature short-time pasteurization.Therefore,B.cereus can enter the market through pasteurized milk and other dairy products,imposing enormous hidden dangers on food safety and human health.Results:In this study,B.cereus 2101(BC)was isolated from milk samples of cows with mastitis.BC grew rapidly with strong hemolysis,making it difficult to prevent mastitis and ensure food security.MAC-T cells were treated with BC and/or Lactobacillus rhamnosus GR-1(LGR-1).Pretreatment with LGR-1 protected the integrity of tight junctions and the expression of zonula occludens-1(ZO-1)and occludin destroyed by BC.Furthermore,LGR-1 pretreatment reduced the expression of NOD-like receptor family member pyrin domain-containing protein 3(NLRP3),caspase recruitment and activation domain(ASC),Caspase-1 p20,gasdermin D(GSDMD)p30,inflammatory factors(interleukin(IL)-1βand IL-18),and cell death induced by BC.Moreover,LGR-1 pretreatment reduced NLRP3 inflammasome activity and increased expressions of ZO-1 and occludin induced by lipopolysaccharides(LPS)+ATP stimulation.MAC-T cells were transfected with NLRP3 si RNA or MCC950 and/or treated with BC and/or LGR-1.NLRP3-si RNA transfection and MCC950 attenuated BC-induced NLRP3 inflammasome activity.Expression of inflammatory cytokines and cell death suggested that the inflammatory pathway might play an important role in the induction of the NLRP3 inflammasome by BC and the protection of LGR-1.Conclusions:These results suggest that LGR-1 might be a probiotic alternative to antibiotics and could be administered to prevent mastitis in dairy cows,thus ensuring food security.

Lactobacillus casei Zhang的甲基转移酶突变体与其野生型的代谢组学比较

DNA甲基化作为表观遗传学的重要组成部分,在细菌的很多生理过程中发挥着重要作用。作者基于超高效液相色谱-质谱联用非靶向代谢组学技术,比较DNA甲基转移酶突变体Lactobacillus casei(L.casei)ZhangΔpglX与野生型L.casei Zhang在对数生长前期(4 h)的代谢差异。共鉴定得到23个显著差异代谢物(P<0.05),主要富集在氨酰-tRNA生物合成、不饱和脂肪酸生物合成、D-谷氨酰胺和D-谷氨酸代谢及半乳糖代谢等代谢途径。结果表明,DNA甲基化表型在对数生长前期可能会影响菌株对氨基酸的合成和利用;另一方面,DNA甲基化表型在对数生长前期可能会调节菌株细胞膜脂肪酸成分,改变细胞膜的通透性和流动性。

Identification of Lactobacillus and Bifidobacterium 16S rRNA Gene in Breast Milk of Some Healthy Women in Kinshasa (DR Congo)

Breast milk is important for infant health. Some of its benefits are due to the presence of a specific population of bacteria in the microflora. However, the microbiome of breast milk is influenced by many parameters such as maternal diet, breastfeeding and geographic location. Culture and non-culture methods have been used in studies of this bacterial population worldwide. But in the DR Congo, there was no study reporting the use of culture-independent techniques to characterize the bacterial diversity of human milk. The aim of this study was to identify the bacterial 16S rRNA gene from two genera Lactobacillus and Bifidobacterium. The 16S rRNA gene was also identified from four species: Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium longum and Bifidobacterium lactis. This analytical cross-sectional study was conducted in Kinshasa. Breast milk from some healthy women was collected from February 2 to 28, 2018. A culture-independent protocol using the classical polymerase chain reaction (PCR) was used to identify the bacterial 16S rRNA gene. The 68 samples of breast milk were collected in a sterile condition. The bacteria-specific ribosomal gene 16S rRNA was detected in 91.18% of Lactobacillus and 32.35% of Bifidobacterium at genus level. At of species level, only Lactobacillus reuteri 16S rRNA gene was identified in 89.71%. The 16S rRNA gene from the other species could not be amplified. There was also an association between educational level and the presence of Bifidobacterium and Lactobacillus 16S rRNA genes in the breast milk (p = 0.008*, p Conclusion: This study demonstrates the presence of the bacterial 16S rRNA gene from Lactobacillus and Bifidobacterium in breast milk at the genus and Lactobacillus reuteri at species level. A further study on the diet, use of antibiotics during pregnancy and lactation practice will provide a better understanding of the microflora of breast milk.

The Latest Research Progress on Application of Lactobacillus acidophilus

Lactobacillus acidophilus belongs to the genus Lactobacillus, Gram-positive bacteria, which mainly colonize the small intestine of animals, can secrete anti-biotin substances, inhibit the growth and reproduction of some intestinal pathogenic bacteria, thereby regulating Intestinal flora, strengthen the absorption and utilization of feed nutrients, improve resistance, and promote animal growth, so it is widely used in livestock and poultry production. This article summarizes the latest research progress and application of Lactobacillus acidophilus, and looks forward to the future development direction in order to provide a theoretical basis for its future research.

Integrative proteomic-transcriptomic analysis revealed the lifestyles of Lactobacillus paracasei H4-11 and Kluyveromyces marxianus L1-1 under co-cultivation conditions

Compared with the rice-acid soup inoculated with single starter,the synergistically intensifi ed rice-acid soup inoculated with Lactobacillus paracasei H4-11(L.paracasei H4-11)and Kluyveromyces marxianus L1-1(K.marxianus L1-1)contained more fl avor compounds.Organic acids mainly included L-lactic acid and the main volatile fl avor component was ethyl acetate.Moreover,the signal intensity of astringency and bitterness and the total concentration of volatile sulfur compounds were reduced.The combined analysis results of RNA sequencing(RNA-seq)technology and 4D label-free quantitative(4D LFQ)proteomics explained the fl avor formation pathways in rice-acid soup inoculated with L.paracasei H4-11 and K.marxianus L1-1.In L.paracasei H4-11,L-lactate dehydrogenase,phosphoglucomutase,acetate kinase,alcohol dehydrogenase and acetyl-CoA were up-regulated and D-lactate dehydrogenase and N-Acetyltransferase were down-regulated.In K.marxianus L1-1,Acetyl-CoA,acetaldehyde dehydrogenase,acyl-coenzyme A,N-acetyltransferase,and L-lactate dehydrogenase were up-regulated and hexokinase,alcohol dehydrogenase,and alcohol O-acetyltransferase were down-regulated.The above up-regulation and down-regulation synergistically promoted the formation of characteristic fl avor compounds(mainly L-lactic acid and ethyl acetate).Enzyme-linked immunoassay(ELISA)and parallel reaction monitoring(PRM)quantitative analysis respectively verifi ed that 5 key metabolic enzymes and 27 proteins in L.paracasei H4-11 and K.marxianus L1-1 were associated with the characteristic fl avor of rice-acid soup,as confi rmed by the quantitative results of 4D LFQ.

大菱鲆肠道乳杆菌Lactobacillus sp.N5的筛选鉴定及其抑制水产病原菌的研究

从大菱鲆(Scophthalmus maximus)肠道内分离出8株乳酸菌,经16S rDNA鉴定为Lactobacillus sp.,以对水产病原菌的抑制和对抗生素的敏感性为指标,研究乳酸菌的特性。其中,菌株N5对鳗弧菌(Vibrio anguillarum)、哈维氏弧菌(V.harveyi)、副溶血弧菌(V.parahaemolyticus)和金黄色葡萄球菌(Staphylococcus aureus)均具有较强的抑制作用,对氨苄青霉素、庆大霉素和罗红霉素敏感。菌株N5发酵上清液经加热、排酸和过氧化氢酶处理后,仍有抑菌作用;经蛋白酶处理后失去抑菌能力,推测菌株N5分泌的抑菌物质为耐热的乳酸菌素,其可以抑制病原菌生物膜的形成。菌株N5在凡纳对虾(Litopenaeus vannamei)肠道定植5 d后,加入鳗弧菌和哈维氏弧菌,继续养殖7 d,死亡率显著降低。本研究结果可为菌株N5制备水产养殖益生菌剂提供实验依据。

Mutation Breeding of Lactobacillus and Its Application in Yoghurt

With the gradual improvement of the quality of people’s life, the disorder of lipid metabolism caused by high-fat diet has become the main reason that affects the health of our people. Hyperlipidemia, hypertension and hyperglycemia have the effect of causing a large number of serious complications, and are also the main factors of cardiovascular disease. Lactic acid bacteria can avoid hyperlipidemia by inhibiting the excessive growth of harmful intestinal bacteria, maintaining the balance of intestinal microecology, absorbing intestinal cholesterol and regulating lipid metabolism. Therefore, this paper focused on the mutation and breeding of Lactobacillus, and analyzed its application in yoghurt, aiming to provide reference for relevant researchers.

Lactobacillus plantarum A3 attenuates ulcerative colitis by modulating gut microbiota and metabolism

Antibiotics are widely used to treat various diseases.However,growing evidence indicates that antibiotic therapy in human life increases the incidence of inflammatory bowel disease(IBD).Therefore,we need appropriate methods to reduce the incidence or symptoms of IBD.In this study,we used lincomycin hydrochloride to construct a gut micro-bial dysbiosis model in mice,and then,constructed an ulcerative colitis(UC)model.Meanwhile,we used Lactobacillus plantarum A3 from equine to treat UC in mice with gut microbial dysbiosis.The results showed that lincomycin hydro-chloride had little effect on the small gut microbiota in mice,but had a more destructive effect on the large intestin.Lactobaillus plantarum A3 alleviated the symptoms of UC in mice,which was reflected in its significantly reduced spleen index and disease activity index(DAl)(p<0.05),inhibited the shortening of colon and alleviated the invasion of inflammatory cells in the colon.Moreover,we found that it played a mitigatory role by inhibiting oxidative stress and regulating inflammatory cytokines in mice.At the same time,it restored the diversity and composition of the colonic microbiota and significantly increased the abundance of beneficial bacteria such as Blautia and Akkermansia(p<0.05);Notably,it significantly increased the concentrations of arachidonoyl ethanolamide phosphate(AEA-P)and cortisone(p<0.05)which have analgesic and anti-inflammatory effects.In conclusion,our study found that Lactobacillus plan-tarum A3 has the potential to regulate UC in mice with gut microbial dysbiosis.