一株耐铬真菌的分离鉴定及基于抗氧化酶的耐铬机制研究  

Isolation and Identification of a Chromium-Tolerant Fungus and its Chromium-Tolerant Mechanism Based on Antioxidant Enzymes Response

作　　者：朱超[1] 马靓琛 王曼婷 马宏瑞[1] 赵澜博 ZHU Chao;MA Jingchen;WANG Manting;MA Hongrui;ZHAO Lanbo(Shaanxi University of Science&Technology,Xi’an 710021,China;Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]陕西科技大学,陕西西安710021 [2]西北工业大学,陕西西安710072

出　　处：《皮革科学与工程》2022年第4期8-13,共6页Leather Science and Engineering

基　　金：国家自然科学基金(22076113)。

摘　　要：从实验室被真菌污染的100 mg/L的1∶1 Cr-EDTA中分离得到一株真菌,经形貌和分子生物学鉴定,该菌株为霜霉菌菌属,最佳生长条件为培养温度为30℃、培养pH为6或7。铬胁迫实验表明该分离株最高可耐受质量浓度为1000 mg/L的六价铬。通过测定该菌株在不同铬浓度下的总抗氧化酶(Total antioxidant enzymes,T-AOC),总超氧化物歧化酶(Total Superoxide Dismutas,T-SOD)和过氧化氢酶(catalase,CAT)活性,研究铬胁迫下该菌株抗氧化酶系的响应路径,以及不同抗氧化酶活性响应的相关性,拟从抗氧化酶系的角度阐明分离株的耐铬机理。结果表明:在Cr胁迫下,T-SOD、T-AOC、CAT活性均呈现增长趋势,其中T-SOD活性增速最快,在Cr质量浓度为155 mg/L时可达到空白对照组的4倍,CAT为对照组的3.8倍,T-AOC是空白对照组的2倍,说明抗氧化酶系活性对于Cr6+胁迫的响应顺序依次为T-SOD、CAT和T-AOC,且T-AOC活性与T-SOD活性、T-AOC活性与过CAT活性、T-SOD活性与CAT活性分别呈线性正相关。A strain of fungus was isolated from 100 mg/L 1∶1 Cr-EDTA solution contaminated by fungi in the laboratory.Results of identification by morphology and molecular biology show that the strain belongs to the genus downy mildew.Its optimal growth conditions are culture temperature of 30℃and pH of 6 or 7.Chromium stress test confirmed that the strain could tolerate the hexavalent chromium with the maximum concentration of 1000 mg/L.By measuring the activities of total antioxidant enzymes(T-AOC),total superoxide dismutase(T-SOD)and catalase(CAT)of the strain under different concentrations of chromium,we investigated the response path of antioxidant enzyme system of the strain and the correlation of different antioxidant enzyme activity response under chromium stress,in order to clarify the chromium resistance mechanism of the strain from the perspective of antioxidant enzyme system.Results show that,under Cr stress,all the activities of T-SOD,T-AOC and CAT showed an increasing trend,among which the activity of T-SOD increased the fastest.When the Cr concentration was 155 mg/L,the activity of T-SOD was 4 times of that of the blank control group,and the activity of CAT was 3.8 times of that of the control group,while the activity of T-AOC was 2 times of that of the control group.These results indicate that the response sequence of antioxidant enzyme activities in the strain to Cr6+stress is T-SOD>CAT>T-AOC,and there is a positive linear correlation between T-AOC and T-SOD activities,T-AOC and over-CAT activities,and T-SOD and CAT activities,respectively.

关 键 词：耐铬真菌 分离鉴定 抗氧化酶 铬鞣废水 六价铬 

分 类 号：X794[环境科学与工程—环境工程]