摘要
对河西走廊荒漠石生可培养细菌进行分离培养,筛选具有紫外线抗性及产紫外辐照保护物质的菌株.以菌株紫外辐照后的存活率和菌株胞外产物对大肠杆菌的紫外保护作用为标准,获得抗性菌株S06-11,并对菌株S06-11进行了16S rRNA基因序列分析.菌株S06-11经发酵培养后,发酵液用乙醇沉淀法提取,Sephadex LH-20柱层析纯化得到活性多糖EPS2.用硫酸-苯酚法和紫外吸收法检测EPS2的总糖含量、蛋白质含量.通过检测EPS2清除活性氧自由基的能力,评价其抗氧化活性.研究发现,菌株S06-11与Arthrobacter sp序列相似性为97.95%,是Arthrobacter属细菌,该菌株发酵产生的胞外多糖EPS2对1,1-二苯基-2-三硝基苯肼、超氧阴离子和羟自由基的清除率分别为68.1%、50.86%和40.08%,具有较强的体外抗氧化性能,是一株具有开发潜力的菌株.
Cultured bacterial strains cloned on stones in a barren desert of Hexi Corridor area were isolated,cultivated,and screened to obtained ultraviolet resistant bacterial isolates in this paper.The viability of strains after exposure to ultraviolet radiation and the protection of extra-cellular products to Escherichia coli from ultraviolet radiation were measured for selecting criteria,the ultraviolet-radiation-resistant bacterial strain S06-11 was obtained.16S rRNA gene sequence analysis of strain S06-11 was subjected for identification.After submerged culture of strain S06-11,the fermentation broth was extracted by ethanol precipitation and purified by Sephadex LH-20 column chromatography to obtain pure active extracellular polysaccharide EPS2.Then phenol-sulfuric acid and UV-spectrophotometer were used to determined the contents of total carbohydrates and protein in EPS2.The antioxidant activities of EPS2 were assessed by means of the scavenging capacities to reactive oxygen species and free radicals.The results show that the similarity between strain S06-11 and Arthrobacter sp sequence is 97.95%,and they are Arthrobacter bacteria.The scavenging rate of polysaccharide EPS2 to 1,1-diphenyl-2-picrylhydrazyl radicals,superoxide anion radicals and hydroxyl-free radicals are 68.1%,50.86%,and 40.08%,respectively.In brief,S06-11 has strong antioxidant properties in vitro and is a potential strain for further research and development.
作者
曾小英
何丽芳
文雅
李师翁
张威
ZENG Xiao-ying;HE Li-fang;WEN Ya;LI Shi-weng;ZHANG Wei(School of Chemical and Biological Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;School of Environmentaland Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resource,Chinese Academy of Sciences,Lanzhou 730000,China)
出处
《兰州交通大学学报》
CAS
2020年第3期103-110,共8页
Journal of Lanzhou Jiaotong University
基金
国家自然科学基金(31870479,31570498,41801045)
中科院对外合作重点项目(131B62KYSB20160014)。
关键词
抗紫外线辐射
胞外多糖
抗氧化活性
UV-radiation-resistant bacteria
extracellular polysaccharide
antioxidant property
