[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temper...[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.展开更多
[Objectives]The paper was to analyze and predict the structure and characteristics of xylanase xynMF13-GH10 gene and its encoded protein.[Methods]xynMF13-GH10 gene was predicted by NCBI and various information analysi...[Objectives]The paper was to analyze and predict the structure and characteristics of xylanase xynMF13-GH10 gene and its encoded protein.[Methods]xynMF13-GH10 gene was predicted by NCBI and various information analysis tools in ExPASy website,as well as SignaIP 5.0,DNAman,TMHMM,SOPMA and SWISS-Model,and the characteristics and functions of protein structure encoded by the gene were predicted.[Results]The gene is 1332 bp in length,the coding region is 1-1332 bp,and the gene encodes 443 amino acids.The xynMF13-GH10 gene has high homology with xylanase in many species,and it has the highest homology with Paraphaeosphaeria sporulosa endoxylanase-like protein,with the consistency reaching 78.91%and e-value reaching 2e-159.The secondary structure consists of 48.31%random curl,30.25%α-helix structure,16.70%extended chain and 4.74%β-corner.[Conclusions]The results provide a reference for revealing the physiological function and expression regulation mechanism of xynMF13-GH10 gene in the future.展开更多
[Objectives]To study the antibacterial effects of extracts from Pinus massoniana Lamb.needles.[Methods]In this experiment,the components from Pinus massoniana Lamb.needles were extracted by systematic solvent extracti...[Objectives]To study the antibacterial effects of extracts from Pinus massoniana Lamb.needles.[Methods]In this experiment,the components from Pinus massoniana Lamb.needles were extracted by systematic solvent extraction method,and the antibacterial activity against four common bacteria,Escherichia coli,Staphylococcus aureus,Bacillus subtilis,Aspergillus flavus and the antibacterial active component were examined for by punch method.[Results]Different solvent extraction rate was different,the rates of petroleum ether,chloroform,ethyl acetate,n-butanol,water extracts were 4.2%,16.7%,17.4%,21.1%,40.6%.All extracts showed inhibitory effect against test bacteria.It was observed that the inhibition of G+was stronger than G-,and the extracts had the best antibacterial activity to Staphylococcus aureus while the weakest to Aspergillus flavus.The antibacterial activity of the components decreased in the order:ethyl acetate extract>n-butanol extract>chloroform extract>petroleum ether extract>aqueous phase.The extracts were stable under ultraviolet radiation(UV)light and long term storage.The antibacterial activity of the extracts was weaker with the increase of pH value when the pH value≤8.[Conclusions]It is inferred that the antibacterial components in the extract of Pinus massoniana needles are widely distributed,and the components with medium polarity or above are the main antibacterial components.展开更多
基金Supported by 2023 Zhanjiang Non-funded Science and Technology Research Plan(2023B01023)2022 University-level Education and Teaching Reform Project of Lingnan Normal University(LingShiJiaoWu2022154).Junxia SONG,bachelor degree,experimenter,research fields:physical geography.
文摘[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.
基金Public Service Platform Project for Industrial Chain Collaborative Innovation(ZHC 2017CB82)Public Service Platform Subproject for Research and Development of Marine Biomedical Resources in the South China Sea(XM-202008-01B2).
文摘[Objectives]The paper was to analyze and predict the structure and characteristics of xylanase xynMF13-GH10 gene and its encoded protein.[Methods]xynMF13-GH10 gene was predicted by NCBI and various information analysis tools in ExPASy website,as well as SignaIP 5.0,DNAman,TMHMM,SOPMA and SWISS-Model,and the characteristics and functions of protein structure encoded by the gene were predicted.[Results]The gene is 1332 bp in length,the coding region is 1-1332 bp,and the gene encodes 443 amino acids.The xynMF13-GH10 gene has high homology with xylanase in many species,and it has the highest homology with Paraphaeosphaeria sporulosa endoxylanase-like protein,with the consistency reaching 78.91%and e-value reaching 2e-159.The secondary structure consists of 48.31%random curl,30.25%α-helix structure,16.70%extended chain and 4.74%β-corner.[Conclusions]The results provide a reference for revealing the physiological function and expression regulation mechanism of xynMF13-GH10 gene in the future.
基金Supported by Zhanjiang Non-funded Science and Technology Research Plan in 2023(2023B01023)School-level Education and Teaching Reform Project of Lingnan Normal University in 2022(LingShiJiaoWu2022154).
文摘[Objectives]To study the antibacterial effects of extracts from Pinus massoniana Lamb.needles.[Methods]In this experiment,the components from Pinus massoniana Lamb.needles were extracted by systematic solvent extraction method,and the antibacterial activity against four common bacteria,Escherichia coli,Staphylococcus aureus,Bacillus subtilis,Aspergillus flavus and the antibacterial active component were examined for by punch method.[Results]Different solvent extraction rate was different,the rates of petroleum ether,chloroform,ethyl acetate,n-butanol,water extracts were 4.2%,16.7%,17.4%,21.1%,40.6%.All extracts showed inhibitory effect against test bacteria.It was observed that the inhibition of G+was stronger than G-,and the extracts had the best antibacterial activity to Staphylococcus aureus while the weakest to Aspergillus flavus.The antibacterial activity of the components decreased in the order:ethyl acetate extract>n-butanol extract>chloroform extract>petroleum ether extract>aqueous phase.The extracts were stable under ultraviolet radiation(UV)light and long term storage.The antibacterial activity of the extracts was weaker with the increase of pH value when the pH value≤8.[Conclusions]It is inferred that the antibacterial components in the extract of Pinus massoniana needles are widely distributed,and the components with medium polarity or above are the main antibacterial components.
