The gut microbiota and it’s metabolism are vital targets of probiotics regulating high fat-diet(HFD)induced hyperlipidemia,which can relieve the pressure caused by the striking growth of sub-health people.Pediococcus...The gut microbiota and it’s metabolism are vital targets of probiotics regulating high fat-diet(HFD)induced hyperlipidemia,which can relieve the pressure caused by the striking growth of sub-health people.Pediococcus pentosaceus PP04(PP04)could colonize in intestine to regulate gut microbiota and it’s metabolites directly,the rebalanced intestinal flora mediated by PP04 could facilitate the secretion of short chain fatty acids to control body weight gain,PP04 intervention also changed bile acid(BA)profiles and enhanced the ileal concentrations of antagonists including tauro-α/β-muricholic acid sodium salt and ursodeoxycholic acid to inhibit intestinal farnesoid X receptor/fibroblast growth factor 15(FXR/FGF15)signaling coupled with the activation of hepatic FXR/small heterodimer partners signaling,which accelerated the hepatic BA de novo synthesis and excretion with feces to eliminate HFD caused hyperlipemia effectively.This study provided important evidence regarding PP04 as dietary supplement to relieve hyperlipidemia by influencing BA enterohepatic circulation.展开更多
BACKGROUND Intestinal dysbiosis has been shown to be associated with the pathogenesis of alcoholic liver disease(ALD), which includes changes in the microbiota composition and bacterial overgrowth, but an effective mi...BACKGROUND Intestinal dysbiosis has been shown to be associated with the pathogenesis of alcoholic liver disease(ALD), which includes changes in the microbiota composition and bacterial overgrowth, but an effective microbe-based therapy is lacking. Pediococcus pentosaceus(P. pentosaceus) CGMCC 7049 is a newly isolated strain of probiotic that has been shown to be resistant to ethanol and bile salts. However, further studies are needed to determine whether P. pentosaceus exerts a protective effect on ALD and to elucidate the potential mechanism.AIM To evaluate the protective effect of the probiotic P. pentosaceus on ethanol-induced liver injury in mice.METHODS A new ethanol-resistant strain of P. pentosaceus CGMCC 7049 was isolated from healthy adults in our laboratory. The chronic plus binge model of experimental ALD was established to evaluate the protective effects. Twenty-eight C57BL/6 mice were randomly divided into three groups: The control group received a pairfed control diet and oral gavage with sterile phosphate buffered saline, the EtOH group received a ten-day Lieber-DeCarli diet containing 5% ethanol and oral gavage with phosphate buffered saline, and the P. pentosaceus group received a 5% ethanol Lieber-DeCarli diet but was treated with P. pentosaceus. One dose of isocaloric maltose dextrin or ethanol was administered by oral gavage on day 11, and the mice were sacrificed nine hours later. Blood and tissue samples(liver and gut) were harvested to evaluate gut barrier function and liver injury-related parameters. Fresh cecal contents were collected, gas chromatography–mass spectrometry was used to measure short-chain fatty acid(SCFA) concentrations, and the microbiota composition was analyzed using 16S rRNA gene sequencing.RESULTS The P. pentosaceus treatment improved ethanol-induced liver injury, with lower alanine aminotransferase, aspartate transaminase and triglyceride levels and decreased neutrophil infiltration. These changes were accompanied by decreased levels of endotoxin and inflammatory cytokines, including interleukin-5, tumor necrosis factor-α, granulocyte colony-stimulating factor, keratinocyte-derived protein chemokine, macrophage inflammatory protein-1α and monocyte chemoattractant protein-1. Ethanol feeding resulted in intestinal dysbiosis and gut barrier disruption, increased relative abundance of potentially pathogenic Escherichia and Staphylococcus, and the depletion of SCFA-producing bacteria, such as Prevotella, Faecalibacterium, and Clostridium. In contrast, P. pentosaceus administration increased the microbial diversity, restored the relative abundance of Lactobacillus, Pediococcus, Prevotella, Clostridium and Akkermansia and increased propionic acid and butyric acid production by modifying SCFA-producing bacteria. Furthermore, the levels of the tight junction protein ZO-1, mucin proteins(mucin [MUC]-1, MUC-2 and MUC-4) and the antimicrobial peptide Reg3β were increased after probiotic supplementation.CONCLUSION Based on these results, the new strain of P. pentosaceus alleviated ethanol-induced liver injury by reversing gut microbiota dysbiosis, regulating intestinal SCFA metabolism, improving intestinal barrier function, and reducing circulating levels of endotoxin and proinflammatory cytokines and chemokines. Thus, this strain is a potential probiotic treatment for ALD.展开更多
Direct-fed microbials（DFM）, generally regarded as safe status, are successfully used in improving rumen ecology, gastro-intestinal health, feed efficiency, milk production and growth rate in ruminants. On the other ...Direct-fed microbials（DFM）, generally regarded as safe status, are successfully used in improving rumen ecology, gastro-intestinal health, feed efficiency, milk production and growth rate in ruminants. On the other hand, methanogenesis in rumen, which accounts for a significant loss of ruminant energy and increased greenhouse gas in environment, is of great concern, therefore, use of DFM for improving productivity without compromising the animal health and ecological sustainability is encouraged. The present study was conducted to investigate the methane reducing potential of bacteriocinogenic strain Pediococcus pentosaceus-34. Since, the culture showed no hemolysis on blood agar and DNase activity, hence, it was considered to be avirulent in nature, a prerequisite for any DFM. The culture also showed tolerance to pH 5.0 for 24 h with 0.5% organic acid mixture, whereas when given a shock for 2 h at different p H and organic acids concentrations, it showed growth at pH 3.0 and 4.0 with 0.1 and 1.0% organic acids, respectively, as having good animal probiotics attributes. The total gas production was significantly（P〈0.05） higher in live pedicoccal culture（LPC） and dead pedicoccal culture（DPC） both with wheat straw, when compared to the control. In sugarcane bagasse, gas production was significantly lower（P〈0.05） with LPC compared to the control and DPC both. Methane was reduced by the inclusion of LPC in sugarcane bagasse（0.07 mL CH4 mg–1 dry matter digestibility） with no effect on other rumen fermentation parameters. However, with wheat straw and LPC total gas, in vitro dry matter digestibility, total volatile fatty acids increased significantly but no reduction in methane production was observed in comparison to the control. Therefore, further research is warranted in this direction, if the bacteriocinogenic strains can be used as DFM for ruminants to improve the ruminant productivity.展开更多
Objective: To examine the survivability and stability of probiotic strains in presence and absence of pharmaceutical excipients for a long period of time at(4 ± 1)℃.Methods: The survival rates of probiotic strai...Objective: To examine the survivability and stability of probiotic strains in presence and absence of pharmaceutical excipients for a long period of time at(4 ± 1)℃.Methods: The survival rates of probiotic strains, Pediococcus pentosaceus GS4(MTCC12683)(NCBI HM044322), GS17(NCBI KJ608061) and Lactobacillus gasseri(ATCC 19992), were evaluated. Probiotic strains were lyophilized individually and in combination of excipients(sorbitol, ascorbic acid, fructose and skim milk). The preparation was monitored for 120 d storing at(4 ± 1)℃. During storage, all the preparations were evaluated for viability and stability of probiotic properties like lactic acid production, antimicrobial effect, water activity, and adherence to epithelial cells.Results: Sorbitol, ascorbic acid and skim milk favoured the viability of freeze-dried cells and sustained probiotic properties during storage. Without excipients(control group),strains showed percentage of survivability not more than 70% while strains with excipients survived for 73%–93% for a long period of time.Conclusions: Commonly used excipients can be considered as a vehicle for delivering active principle in probiotic formulation and for sustaining the viability and stability of probiotic strains for a period of 120 d.展开更多
This study was performed to determine the effects of bacteriocin-producing and non-bacteriocin-producing Pediococcus acidilactici strains on the immune system and intestinal flora of normal mice.Two P.acidilactici str...This study was performed to determine the effects of bacteriocin-producing and non-bacteriocin-producing Pediococcus acidilactici strains on the immune system and intestinal flora of normal mice.Two P.acidilactici strains with antibacterial activity(P.acidilactici CCFM28 and CCFM18)were obtained based on the inhibition-zone assay.The produced components were identified as bacteriocins through protease treatment,pH adjustment and hydrogen peroxide treatment.Bacteriocin-producing and non-bacteriocin-producing P.acidilactici strains(P.acidilactici CCFM28,CCFM18 and NT17-3)caused significant changes in serum immune factors and intestinal flora of normal mice.After 14 days of intervention,the relative abundance of Firmicutes was significantly decreased,but that of Proteobacteria was significantly increased at the phylum level.At the genus level,the administration of three P.acidilactici strains resulted in the downregulation of Blautia and the upregulation of Ruminococcus and Lactobacillus.Furthermore,there were also different regulations on some probiotic strains,such as Bifidobacterium,Coprococcus and Akkermansia,which were closely related to the antibacterial ability of the bacteriocin and the type of strain.The results indicated that the intervention of different P.acidilactici strains could differently change the structure of intestinal flora in normal mice,which provided theoretical guidance for the selective use of bacteriocin-producing strains for health regulation in the future.展开更多
Two lactic acid bacteria strains (At1BEAE22 and At344E21) isolated during tchapalo production were identified on the basis of phenotypic analyses. Bacteriocins produced by these strains were tested for their antimicro...Two lactic acid bacteria strains (At1BEAE22 and At344E21) isolated during tchapalo production were identified on the basis of phenotypic analyses. Bacteriocins produced by these strains were tested for their antimicrobial activities using well diffusion agar method. Heat resistance, pH sensitivity and enzyme treatments were also analyzed. Results showed that both lactic acid bacteria strains were identified as Pediococcus acidilactici. Their bacteriocins inhibited growth of Lactobacillus delbrueckii F/31, Listeria innocua ATCC 33090, Enterococcus faecalis, Enterococcus faecalis ATCC 29212, Streptococcus sp, Enterococcus faecalis CIP 105042 and Enterococcus faecium ATCC 51558. These bacteriocins were heat stable at 60°C for 30 min for all indicator bacteria. However, they remained active only against Lactobacillus delbrueckii and Listeria innocua at 121°C for 60 min. Moreover, they were active in a wide range of pH (3 to 9) with a maximum activity observed at pH 5 and 6 on all indicator bacteria. But, bacteriocin from Pediococcus acidilactici At34E21 was more stable at acidic pH than basic one. The fact that the bacteriocin was inactivated by proteinase K and α-chymotrypsin indicated its proteinaceous nature, a general characteristics of bacteriocins.展开更多
Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars.However,one barrier for practical application is the sustained cell via...Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars.However,one barrier for practical application is the sustained cell viability in the consequent fermentation step to compete the fermentable sugars with fermenting strains,resulting in sugar loss and reduced target product yield.This study investigated the competitive growth property between the biodetoxification fungus Paecilomyces variotii FN89 and the L-lactic acid bacterium Pediococcus acidilactici ZY271 under varying temperature and lactic acid osmatic stress.The results show that the L-lactic acid bacterium Ped.acidilactici ZY271 showed less thermotolerance to Pae.variotii FN89 at high temperature of 45°C to 50°C in both synthetic medium and wheat straw hydrolysate.In the higher temperature environment,the growth of the biodetoxification strian failed to compete with the lactic acid fermentation strain and was quickly eliminated from the fermentation system.The high temperature fermentation facilitated a fast transition from the detoxification stage to the fermentation stage for higher production of L-lactic acid.展开更多
Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade mi...Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.展开更多
Most methods used by food industries to decontaminate eggs involve washing of egg surface with various chemicals. In this study, the effectiveness of two organic decontaminants viz., acidified sodium chlorite (ASC) an...Most methods used by food industries to decontaminate eggs involve washing of egg surface with various chemicals. In this study, the effectiveness of two organic decontaminants viz., acidified sodium chlorite (ASC) and cell free culture supernatant (CFCS) of two lactic acid bacteria (Lactobacillus plantarum and Pediococcus cerevisiae) was evaluated for the decontamination of spiked Salmonella Typhimurium on chicken egg shell surface. Acidified sodium chlorite at 100 μl/L concentration with the contact time of 20 min completely inhibited S. Typhimurium on egg shell surface while at 50 μl/L concentration 1 - 2 log10 units reduction was observed in counts of S. Typhimurium as compared to control group. Likewise, CFCS of P. cerevisiae completely inhibited the growth of S. Typhimurium on 30 min contact, whereas L. plantarum and combination of both were revealed significant reduction in the counts of S. Typhimurium counts.展开更多
Twenty-two lactic acid bacteria （LAB） strains isolated from Argentinean goat dairy products were evaluated for its biochemical properties and esterase activities relevant to flavor development. Streptococcus thermop...Twenty-two lactic acid bacteria （LAB） strains isolated from Argentinean goat dairy products were evaluated for its biochemical properties and esterase activities relevant to flavor development. Streptococcus thermophilus （UNSE314）, Lactobacillus （L.） delbrueckii subsp, bulgaricus （UNSE309）, L. rhamnosus （UNSE308）, L. plantarum （UNSE287, UNSE316, UNSE317） and Pediococcus pentosaceus （UNSE315） strains presented high acidifying activity. All strains tested metabolized citrate and produced diacetyl-acetoin in goat milk. Based on these results, 10 strains with the best performance in diverse technological properties were selected to determine esterolytic activity. In all evaluated strains, esterase specific activity （ESA） was detected on ct-naphthyl （ct-NA） acetate and 13-naphthyl （[3-NA） acetate, propionate, eaprylate and ct-NA butyrate. No activity was detected on [3-NA laurate. The highest values were detected when using a-NA instead of fI-NA derivatives as substrate. In Pediocoecus strains, wide variability in ESA were observed, which were species- and strain-specific. These results allow us to select strains with biochemical properties and esterase activities to design starter and adjunct cultures that contribute to flavor development during cheese ripening, thus preserving the typical organoleptic characteristics of Argentinean goat cheeses.展开更多
Indigenous fermented foods are known for their nutritional and functional properties but they are often spoiled by pathogenic bacteria that can constitute a food safety problem. “Gappal” is a no-thermal treat food b...Indigenous fermented foods are known for their nutritional and functional properties but they are often spoiled by pathogenic bacteria that can constitute a food safety problem. “Gappal” is a no-thermal treat food based on millet dough and milk and its production conditions can constitute a food safety problem. The aim of this study was to screen and identify LAB producing Bacteriocin-like inhibitory substances using a matrix similar to “Gappal”. The detection of potential BLIS was first performed using overlaid method after enrichment of samples in whey and millet dough. The isolates demonstrating inhibiting area were preselected, purified and tested for the presence of antibacterial properties using their neutralized cell-free culture supernatant and subsequently treated with catalase in combination with protease, pepsin or trypsin. The antimicrobial effect of two isolates (Gbf48 and Gbf50) after growth on MRS broth over 12 h at 30?C were active against E. faecalis ATCC 19433, M. luteus ATCC 49732, S. aureus ATCC 2523, L. monocytogenes, B. megaterium, B. sphaericus and B. cereus with an activity of 2560 AU/mL. The 16S RNA gene sequencing identification indicated that these isolates are Pediococcus acidilactici. Gbf 48 and Gbf 50 could be used to improve preservative factors for a controlled fermentation of non thermal treatment fermented food for their potential of acidification adds to BLIS production.展开更多
Microbial fermentation could produce many active substances in green and pollution-free ways.In recent years,studies on the hypoglycemic ability of microorganisms had become a trending topic in the prevention and trea...Microbial fermentation could produce many active substances in green and pollution-free ways.In recent years,studies on the hypoglycemic ability of microorganisms had become a trending topic in the prevention and treatment of diabetes.Garlic is a food containing a variety of biologically active substances and physiological functions,but it is not accepted by the general public because of its strong pungent smell.In our study,the microorganisms with potential hypoglycemic effect were screened from strains resistant to garlic juice.As a result,41 strains of Bacillus,157 strains of lactic acid bacteria,and 23 strains of yeast with tolerance of garlic juice were screened from the selected 568 strains.After primary screening ofα-amylase inhibitor,it was found that 15 Bacillus and 9 lactic acid bacteria had highα-amylase inhibitory activity.Besides,afterα-glucosidase inhibitor re-screening,Pediococcus acidilactici Z1 with highα-amylase inhibitory activity andα-glucosidase inhibitory activity was screened out.The results of fermented garlic showed that the inhibition rate ofα-amylase andα-glucosidase of garlic from different origins were significantly increased from 59.09 to 63.99%(p<0.01)and from 52.71 to 71.93%(p<0.01)after Z1 fermentation,respectively.The improvement rates ofα-amylase andα-glucosidase were 107.69 to 287.32%,and 197.74 to 239.86%,respectively.In a word,this study provides a theoretical and experimental basis for the development of new functional garlic products.展开更多
Routine microbial inactivation procedures used in microbiology laboratories must be verified.In this study,the efficacy of surface disinfection using 70%Isopropanol,0.45%Presept,and 1%Virkon was tested against 24 bact...Routine microbial inactivation procedures used in microbiology laboratories must be verified.In this study,the efficacy of surface disinfection using 70%Isopropanol,0.45%Presept,and 1%Virkon was tested against 24 bacterial strains commonly handled in aquaculture microbiology laboratories.Isopropanol was ineffective against Nocardia asteroides NCIMB 1290,while Virkon was not effective against Aeromonas eucrenophila NCIMB 74 or Pediococcus acidilacti R52037.展开更多
基金supported by the Jilin Province Science and Technology Plan Project(20230402032GH)the Jilin Province Science and Technology Development Project(20220508115RC).
文摘The gut microbiota and it’s metabolism are vital targets of probiotics regulating high fat-diet(HFD)induced hyperlipidemia,which can relieve the pressure caused by the striking growth of sub-health people.Pediococcus pentosaceus PP04(PP04)could colonize in intestine to regulate gut microbiota and it’s metabolites directly,the rebalanced intestinal flora mediated by PP04 could facilitate the secretion of short chain fatty acids to control body weight gain,PP04 intervention also changed bile acid(BA)profiles and enhanced the ileal concentrations of antagonists including tauro-α/β-muricholic acid sodium salt and ursodeoxycholic acid to inhibit intestinal farnesoid X receptor/fibroblast growth factor 15(FXR/FGF15)signaling coupled with the activation of hepatic FXR/small heterodimer partners signaling,which accelerated the hepatic BA de novo synthesis and excretion with feces to eliminate HFD caused hyperlipemia effectively.This study provided important evidence regarding PP04 as dietary supplement to relieve hyperlipidemia by influencing BA enterohepatic circulation.
基金Supported by National Natural Science Foundation of China,No. 81330011,No. 81790631,No. 81570512,and No. 81790633Science Fund for Creative Research Groups of the National Natural Science Foundation of China,No. 81121002National Key Research and Development Program of China,No. 2018YFC2000500。
文摘BACKGROUND Intestinal dysbiosis has been shown to be associated with the pathogenesis of alcoholic liver disease(ALD), which includes changes in the microbiota composition and bacterial overgrowth, but an effective microbe-based therapy is lacking. Pediococcus pentosaceus(P. pentosaceus) CGMCC 7049 is a newly isolated strain of probiotic that has been shown to be resistant to ethanol and bile salts. However, further studies are needed to determine whether P. pentosaceus exerts a protective effect on ALD and to elucidate the potential mechanism.AIM To evaluate the protective effect of the probiotic P. pentosaceus on ethanol-induced liver injury in mice.METHODS A new ethanol-resistant strain of P. pentosaceus CGMCC 7049 was isolated from healthy adults in our laboratory. The chronic plus binge model of experimental ALD was established to evaluate the protective effects. Twenty-eight C57BL/6 mice were randomly divided into three groups: The control group received a pairfed control diet and oral gavage with sterile phosphate buffered saline, the EtOH group received a ten-day Lieber-DeCarli diet containing 5% ethanol and oral gavage with phosphate buffered saline, and the P. pentosaceus group received a 5% ethanol Lieber-DeCarli diet but was treated with P. pentosaceus. One dose of isocaloric maltose dextrin or ethanol was administered by oral gavage on day 11, and the mice were sacrificed nine hours later. Blood and tissue samples(liver and gut) were harvested to evaluate gut barrier function and liver injury-related parameters. Fresh cecal contents were collected, gas chromatography–mass spectrometry was used to measure short-chain fatty acid(SCFA) concentrations, and the microbiota composition was analyzed using 16S rRNA gene sequencing.RESULTS The P. pentosaceus treatment improved ethanol-induced liver injury, with lower alanine aminotransferase, aspartate transaminase and triglyceride levels and decreased neutrophil infiltration. These changes were accompanied by decreased levels of endotoxin and inflammatory cytokines, including interleukin-5, tumor necrosis factor-α, granulocyte colony-stimulating factor, keratinocyte-derived protein chemokine, macrophage inflammatory protein-1α and monocyte chemoattractant protein-1. Ethanol feeding resulted in intestinal dysbiosis and gut barrier disruption, increased relative abundance of potentially pathogenic Escherichia and Staphylococcus, and the depletion of SCFA-producing bacteria, such as Prevotella, Faecalibacterium, and Clostridium. In contrast, P. pentosaceus administration increased the microbial diversity, restored the relative abundance of Lactobacillus, Pediococcus, Prevotella, Clostridium and Akkermansia and increased propionic acid and butyric acid production by modifying SCFA-producing bacteria. Furthermore, the levels of the tight junction protein ZO-1, mucin proteins(mucin [MUC]-1, MUC-2 and MUC-4) and the antimicrobial peptide Reg3β were increased after probiotic supplementation.CONCLUSION Based on these results, the new strain of P. pentosaceus alleviated ethanol-induced liver injury by reversing gut microbiota dysbiosis, regulating intestinal SCFA metabolism, improving intestinal barrier function, and reducing circulating levels of endotoxin and proinflammatory cytokines and chemokines. Thus, this strain is a potential probiotic treatment for ALD.
基金a part of a PhD project of Sanjay Kumar that was supported by NDRI (ICAR) fellowshipNational Initiative on Climate Resilient Agriculture, India (NICRA) for providing partial support
文摘Direct-fed microbials（DFM）, generally regarded as safe status, are successfully used in improving rumen ecology, gastro-intestinal health, feed efficiency, milk production and growth rate in ruminants. On the other hand, methanogenesis in rumen, which accounts for a significant loss of ruminant energy and increased greenhouse gas in environment, is of great concern, therefore, use of DFM for improving productivity without compromising the animal health and ecological sustainability is encouraged. The present study was conducted to investigate the methane reducing potential of bacteriocinogenic strain Pediococcus pentosaceus-34. Since, the culture showed no hemolysis on blood agar and DNase activity, hence, it was considered to be avirulent in nature, a prerequisite for any DFM. The culture also showed tolerance to pH 5.0 for 24 h with 0.5% organic acid mixture, whereas when given a shock for 2 h at different p H and organic acids concentrations, it showed growth at pH 3.0 and 4.0 with 0.1 and 1.0% organic acids, respectively, as having good animal probiotics attributes. The total gas production was significantly（P〈0.05） higher in live pedicoccal culture（LPC） and dead pedicoccal culture（DPC） both with wheat straw, when compared to the control. In sugarcane bagasse, gas production was significantly lower（P〈0.05） with LPC compared to the control and DPC both. Methane was reduced by the inclusion of LPC in sugarcane bagasse（0.07 mL CH4 mg–1 dry matter digestibility） with no effect on other rumen fermentation parameters. However, with wheat straw and LPC total gas, in vitro dry matter digestibility, total volatile fatty acids increased significantly but no reduction in methane production was observed in comparison to the control. Therefore, further research is warranted in this direction, if the bacteriocinogenic strains can be used as DFM for ruminants to improve the ruminant productivity.
基金supported by the management of VIT University for intramural research fund(RGEMS-2017)
文摘Objective: To examine the survivability and stability of probiotic strains in presence and absence of pharmaceutical excipients for a long period of time at(4 ± 1)℃.Methods: The survival rates of probiotic strains, Pediococcus pentosaceus GS4(MTCC12683)(NCBI HM044322), GS17(NCBI KJ608061) and Lactobacillus gasseri(ATCC 19992), were evaluated. Probiotic strains were lyophilized individually and in combination of excipients(sorbitol, ascorbic acid, fructose and skim milk). The preparation was monitored for 120 d storing at(4 ± 1)℃. During storage, all the preparations were evaluated for viability and stability of probiotic properties like lactic acid production, antimicrobial effect, water activity, and adherence to epithelial cells.Results: Sorbitol, ascorbic acid and skim milk favoured the viability of freeze-dried cells and sustained probiotic properties during storage. Without excipients(control group),strains showed percentage of survivability not more than 70% while strains with excipients survived for 73%–93% for a long period of time.Conclusions: Commonly used excipients can be considered as a vehicle for delivering active principle in probiotic formulation and for sustaining the viability and stability of probiotic strains for a period of 120 d.
基金supported by the National Natural Science Foundation of China Program(32021005)the Natural Science Foundation of Jiangsu Province(BK20200084)+2 种基金Projects of Innovation and Development Pillar Program for Key Industries in Southern Xinjiang of Xinjiang Production and Construction Corps(2018DB002)National First Class Discipline Program of Food Science and Technology(JUFSTR20180102)the Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province。
文摘This study was performed to determine the effects of bacteriocin-producing and non-bacteriocin-producing Pediococcus acidilactici strains on the immune system and intestinal flora of normal mice.Two P.acidilactici strains with antibacterial activity(P.acidilactici CCFM28 and CCFM18)were obtained based on the inhibition-zone assay.The produced components were identified as bacteriocins through protease treatment,pH adjustment and hydrogen peroxide treatment.Bacteriocin-producing and non-bacteriocin-producing P.acidilactici strains(P.acidilactici CCFM28,CCFM18 and NT17-3)caused significant changes in serum immune factors and intestinal flora of normal mice.After 14 days of intervention,the relative abundance of Firmicutes was significantly decreased,but that of Proteobacteria was significantly increased at the phylum level.At the genus level,the administration of three P.acidilactici strains resulted in the downregulation of Blautia and the upregulation of Ruminococcus and Lactobacillus.Furthermore,there were also different regulations on some probiotic strains,such as Bifidobacterium,Coprococcus and Akkermansia,which were closely related to the antibacterial ability of the bacteriocin and the type of strain.The results indicated that the intervention of different P.acidilactici strains could differently change the structure of intestinal flora in normal mice,which provided theoretical guidance for the selective use of bacteriocin-producing strains for health regulation in the future.
文摘Two lactic acid bacteria strains (At1BEAE22 and At344E21) isolated during tchapalo production were identified on the basis of phenotypic analyses. Bacteriocins produced by these strains were tested for their antimicrobial activities using well diffusion agar method. Heat resistance, pH sensitivity and enzyme treatments were also analyzed. Results showed that both lactic acid bacteria strains were identified as Pediococcus acidilactici. Their bacteriocins inhibited growth of Lactobacillus delbrueckii F/31, Listeria innocua ATCC 33090, Enterococcus faecalis, Enterococcus faecalis ATCC 29212, Streptococcus sp, Enterococcus faecalis CIP 105042 and Enterococcus faecium ATCC 51558. These bacteriocins were heat stable at 60°C for 30 min for all indicator bacteria. However, they remained active only against Lactobacillus delbrueckii and Listeria innocua at 121°C for 60 min. Moreover, they were active in a wide range of pH (3 to 9) with a maximum activity observed at pH 5 and 6 on all indicator bacteria. But, bacteriocin from Pediococcus acidilactici At34E21 was more stable at acidic pH than basic one. The fact that the bacteriocin was inactivated by proteinase K and α-chymotrypsin indicated its proteinaceous nature, a general characteristics of bacteriocins.
基金The National Key R&D Program of China(2023YFA0914400)the National Natural Science Foundation of China(32301269)+1 种基金China Postdoctoral Science Foundation(2023M741175)the Yangfan Project of Science and Technology Committee of Shanghai Municipality(23YF1409900).
文摘Biodetoxification fungus selectively degrades toxic inhibitors generated from pretreatment of lignocellulose without consuming fermentable sugars.However,one barrier for practical application is the sustained cell viability in the consequent fermentation step to compete the fermentable sugars with fermenting strains,resulting in sugar loss and reduced target product yield.This study investigated the competitive growth property between the biodetoxification fungus Paecilomyces variotii FN89 and the L-lactic acid bacterium Pediococcus acidilactici ZY271 under varying temperature and lactic acid osmatic stress.The results show that the L-lactic acid bacterium Ped.acidilactici ZY271 showed less thermotolerance to Pae.variotii FN89 at high temperature of 45°C to 50°C in both synthetic medium and wheat straw hydrolysate.In the higher temperature environment,the growth of the biodetoxification strian failed to compete with the lactic acid fermentation strain and was quickly eliminated from the fermentation system.The high temperature fermentation facilitated a fast transition from the detoxification stage to the fermentation stage for higher production of L-lactic acid.
基金The Long-Term Research Grant(LRGS)of the Ministry of Education of Malaysia supported this work
文摘Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.
文摘Most methods used by food industries to decontaminate eggs involve washing of egg surface with various chemicals. In this study, the effectiveness of two organic decontaminants viz., acidified sodium chlorite (ASC) and cell free culture supernatant (CFCS) of two lactic acid bacteria (Lactobacillus plantarum and Pediococcus cerevisiae) was evaluated for the decontamination of spiked Salmonella Typhimurium on chicken egg shell surface. Acidified sodium chlorite at 100 μl/L concentration with the contact time of 20 min completely inhibited S. Typhimurium on egg shell surface while at 50 μl/L concentration 1 - 2 log10 units reduction was observed in counts of S. Typhimurium as compared to control group. Likewise, CFCS of P. cerevisiae completely inhibited the growth of S. Typhimurium on 30 min contact, whereas L. plantarum and combination of both were revealed significant reduction in the counts of S. Typhimurium counts.
文摘Twenty-two lactic acid bacteria （LAB） strains isolated from Argentinean goat dairy products were evaluated for its biochemical properties and esterase activities relevant to flavor development. Streptococcus thermophilus （UNSE314）, Lactobacillus （L.） delbrueckii subsp, bulgaricus （UNSE309）, L. rhamnosus （UNSE308）, L. plantarum （UNSE287, UNSE316, UNSE317） and Pediococcus pentosaceus （UNSE315） strains presented high acidifying activity. All strains tested metabolized citrate and produced diacetyl-acetoin in goat milk. Based on these results, 10 strains with the best performance in diverse technological properties were selected to determine esterolytic activity. In all evaluated strains, esterase specific activity （ESA） was detected on ct-naphthyl （ct-NA） acetate and 13-naphthyl （[3-NA） acetate, propionate, eaprylate and ct-NA butyrate. No activity was detected on [3-NA laurate. The highest values were detected when using a-NA instead of fI-NA derivatives as substrate. In Pediocoecus strains, wide variability in ESA were observed, which were species- and strain-specific. These results allow us to select strains with biochemical properties and esterase activities to design starter and adjunct cultures that contribute to flavor development during cheese ripening, thus preserving the typical organoleptic characteristics of Argentinean goat cheeses.
文摘Indigenous fermented foods are known for their nutritional and functional properties but they are often spoiled by pathogenic bacteria that can constitute a food safety problem. “Gappal” is a no-thermal treat food based on millet dough and milk and its production conditions can constitute a food safety problem. The aim of this study was to screen and identify LAB producing Bacteriocin-like inhibitory substances using a matrix similar to “Gappal”. The detection of potential BLIS was first performed using overlaid method after enrichment of samples in whey and millet dough. The isolates demonstrating inhibiting area were preselected, purified and tested for the presence of antibacterial properties using their neutralized cell-free culture supernatant and subsequently treated with catalase in combination with protease, pepsin or trypsin. The antimicrobial effect of two isolates (Gbf48 and Gbf50) after growth on MRS broth over 12 h at 30?C were active against E. faecalis ATCC 19433, M. luteus ATCC 49732, S. aureus ATCC 2523, L. monocytogenes, B. megaterium, B. sphaericus and B. cereus with an activity of 2560 AU/mL. The 16S RNA gene sequencing identification indicated that these isolates are Pediococcus acidilactici. Gbf 48 and Gbf 50 could be used to improve preservative factors for a controlled fermentation of non thermal treatment fermented food for their potential of acidification adds to BLIS production.
基金supported by the program of Key Laboratory of Industrial Biotechnology of Ministry of Education in Jiangnan University(KLIB-KF202105)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+1 种基金Program of Introducing Talents of Discipline to Universities(No.111-2-06)the National High Technology Research and Development Program 863(No.2018YFD0400403).
文摘Microbial fermentation could produce many active substances in green and pollution-free ways.In recent years,studies on the hypoglycemic ability of microorganisms had become a trending topic in the prevention and treatment of diabetes.Garlic is a food containing a variety of biologically active substances and physiological functions,but it is not accepted by the general public because of its strong pungent smell.In our study,the microorganisms with potential hypoglycemic effect were screened from strains resistant to garlic juice.As a result,41 strains of Bacillus,157 strains of lactic acid bacteria,and 23 strains of yeast with tolerance of garlic juice were screened from the selected 568 strains.After primary screening ofα-amylase inhibitor,it was found that 15 Bacillus and 9 lactic acid bacteria had highα-amylase inhibitory activity.Besides,afterα-glucosidase inhibitor re-screening,Pediococcus acidilactici Z1 with highα-amylase inhibitory activity andα-glucosidase inhibitory activity was screened out.The results of fermented garlic showed that the inhibition rate ofα-amylase andα-glucosidase of garlic from different origins were significantly increased from 59.09 to 63.99%(p<0.01)and from 52.71 to 71.93%(p<0.01)after Z1 fermentation,respectively.The improvement rates ofα-amylase andα-glucosidase were 107.69 to 287.32%,and 197.74 to 239.86%,respectively.In a word,this study provides a theoretical and experimental basis for the development of new functional garlic products.
文摘Routine microbial inactivation procedures used in microbiology laboratories must be verified.In this study,the efficacy of surface disinfection using 70%Isopropanol,0.45%Presept,and 1%Virkon was tested against 24 bacterial strains commonly handled in aquaculture microbiology laboratories.Isopropanol was ineffective against Nocardia asteroides NCIMB 1290,while Virkon was not effective against Aeromonas eucrenophila NCIMB 74 or Pediococcus acidilacti R52037.
