Bacteria contamination in Auricularia auricular culture bags reduces yield and increases the risk of food safety.In this study,5 species of bacteria,mainly gram-positive bacteria including three species of Bacillus sp...Bacteria contamination in Auricularia auricular culture bags reduces yield and increases the risk of food safety.In this study,5 species of bacteria,mainly gram-positive bacteria including three species of Bacillus spp.,Arthrobacter arilaitensis and Staphylococcus warneri,were isolated and identifi ed from bacteria-contaminated A.auricular culture bags.An in silico predicted antimicrobial peptide from theβ-1,3-glucan-binding protein sequence of Penaeus vannamei,designated Pv GBP2(FLKLGRKSRYGMLKL),was screened and its antibacterial effect and mechanism of action on the isolated Bacillus spp.explored.The minimal inhibitory concentrations(MIC)of Pv GBP2 on Bacillus spp.were 15.6–31.25μg/m L.Peptide Pv GBP2 could inhibit Bacillus subtilis in A.auricular culture bags to maintain growth and yield of A.auricular.Transmission electron microscopy(TEM)revealed that Pv GBP2 kills bacteria by perforating the cell wall,destroying membrane integrity and resulting in the leakage of intracellular solutes.In addition,Pv GBP2 inhibits biofi lm formation by B.subtilis by 90.6%at 1×MIC.Thus,peptide Pv GBP2 could be potentially applied as an antibacterial agent to control bacterial infection of A.auricular cultivation and the spread of foodborne pathogens.展开更多
[Objective] To explore the optimal conditions for extracting polysaccharide from Auricularia auricular,and to study its physiochemical properties and antibacterial activities.[Method] The extraction conditions for Aur...[Objective] To explore the optimal conditions for extracting polysaccharide from Auricularia auricular,and to study its physiochemical properties and antibacterial activities.[Method] The extraction conditions for Auricularia auricular polysaccharides were optimized by orthogonal test,and its physiochemical characteristics and antagonistic activities on bacteria and molds were tested.[Result] The optimized condition was with sample to liquid ratio of 1:50,temperature of 90 ℃ and extraction time of 2.5 h.Under the optimized condition,the yield of polysaccharide was 7.3%,with polysaccharide content of 77.81 %.Containing aldose and amylase,the polysaccharides of Auricularia auricular was soluble in water.The inhibitory effect on bacteria was significantly stronger than on molds that the minimum diameter of inhibition zone for bacteria is 12.7 mm,while 7.9 mm for the molds.[Conclusion] This study provides scientific basis for the development and utilization of Auricularia auricular polysaccharides.展开更多
[Objective]This experiment aimed to study the extraction technology of Auricularia auricula polysaccharide(APS).[Method] Polysaccharide yield was regarded as studying target.Based on the single factor experiment resul...[Objective]This experiment aimed to study the extraction technology of Auricularia auricula polysaccharide(APS).[Method] Polysaccharide yield was regarded as studying target.Based on the single factor experiment results,orthogonal experiment design was applied to study the effect of liquid-solid ratio,extraction time,extraction temperature on polysaccharide yield.[Result]The results showed that extraction temperature was an important factor that affects the yield of crude polysaccharide,the optimal technology condition of water extraction way was liquid-solid ratio of 1:70(g:ml),4-hour extraction time with temperature at 100 ℃.[Conclusion] The yield of Auricularia auricular polysaccharide was 42.56% under the above mentioned condition.展开更多
基金sponsored by National Key R&D Program of China(2020YFD09009)。
文摘Bacteria contamination in Auricularia auricular culture bags reduces yield and increases the risk of food safety.In this study,5 species of bacteria,mainly gram-positive bacteria including three species of Bacillus spp.,Arthrobacter arilaitensis and Staphylococcus warneri,were isolated and identifi ed from bacteria-contaminated A.auricular culture bags.An in silico predicted antimicrobial peptide from theβ-1,3-glucan-binding protein sequence of Penaeus vannamei,designated Pv GBP2(FLKLGRKSRYGMLKL),was screened and its antibacterial effect and mechanism of action on the isolated Bacillus spp.explored.The minimal inhibitory concentrations(MIC)of Pv GBP2 on Bacillus spp.were 15.6–31.25μg/m L.Peptide Pv GBP2 could inhibit Bacillus subtilis in A.auricular culture bags to maintain growth and yield of A.auricular.Transmission electron microscopy(TEM)revealed that Pv GBP2 kills bacteria by perforating the cell wall,destroying membrane integrity and resulting in the leakage of intracellular solutes.In addition,Pv GBP2 inhibits biofi lm formation by B.subtilis by 90.6%at 1×MIC.Thus,peptide Pv GBP2 could be potentially applied as an antibacterial agent to control bacterial infection of A.auricular cultivation and the spread of foodborne pathogens.
文摘[Objective] To explore the optimal conditions for extracting polysaccharide from Auricularia auricular,and to study its physiochemical properties and antibacterial activities.[Method] The extraction conditions for Auricularia auricular polysaccharides were optimized by orthogonal test,and its physiochemical characteristics and antagonistic activities on bacteria and molds were tested.[Result] The optimized condition was with sample to liquid ratio of 1:50,temperature of 90 ℃ and extraction time of 2.5 h.Under the optimized condition,the yield of polysaccharide was 7.3%,with polysaccharide content of 77.81 %.Containing aldose and amylase,the polysaccharides of Auricularia auricular was soluble in water.The inhibitory effect on bacteria was significantly stronger than on molds that the minimum diameter of inhibition zone for bacteria is 12.7 mm,while 7.9 mm for the molds.[Conclusion] This study provides scientific basis for the development and utilization of Auricularia auricular polysaccharides.
文摘[Objective]This experiment aimed to study the extraction technology of Auricularia auricula polysaccharide(APS).[Method] Polysaccharide yield was regarded as studying target.Based on the single factor experiment results,orthogonal experiment design was applied to study the effect of liquid-solid ratio,extraction time,extraction temperature on polysaccharide yield.[Result]The results showed that extraction temperature was an important factor that affects the yield of crude polysaccharide,the optimal technology condition of water extraction way was liquid-solid ratio of 1:70(g:ml),4-hour extraction time with temperature at 100 ℃.[Conclusion] The yield of Auricularia auricular polysaccharide was 42.56% under the above mentioned condition.
