富集培养条件下湖泊和沿海海域水体硫酸盐还原菌的耐氧性特征  

Oxygen Tolerance of Sulfate Reducing Bacteria in Fresh and Coastal Sea Waters under Enrichment Culture Conditions

作　　者：陈亚文 张朝晖[1] CHEN Yawen;ZHANG Zhaohui(Ocean College of Zhejiang University,Zhoushan 316021,China)

机构地区：[1]浙江大学海洋学院

出　　处：《高校地质学报》2019年第5期705-713,共9页Geological Journal of China Universities

基　　金：国家自然科学基金（41473069）

摘　　要：硫酸盐还原菌(sulfate-reducing bacteria,SRB)是一类兼性厌氧菌,在湖泊和海洋有机物矿化过程和生物源性黄铁矿的生成过程中都扮演着重要角色。环境溶解氧浓度对硫酸盐还原过程影响较大,硫酸盐还原菌在水体中的耐氧性是目前的研究热点。文章采集了象山港和水口水库不同溶解氧水平下的水样,并在相应的溶解氧梯度下进行富集培养,以探讨不同溶解氧浓度下硫酸盐还原菌的耐氧性特征及硫代谢相关菌的组成。结果显示,在富集培养条件下湖泊和沿海海域中Desulfovibrio(脱硫弧菌属)和Desulfomicrobium(脱硫微菌属)为主要硫酸盐还原细菌,而Shewanella(希瓦氏菌属)和Sulfurospirillum(硫小螺体属)为其硫代谢相关菌。Desulfovibrio的相对丰度与溶解氧水平密切相关,随溶解氧浓度的减少,其相对丰度增加。SRB的耐氧上限为6.68 mg/L,明显高于以往纯培养或共培养的耐氧上限值。作者推测这不仅与其高氧环境的适应策略有关,还可能得益于共存菌的贡献,后者可能通过消耗环境中的氧为Desulfovibrio提供生态位,提高其耐氧水平。Sulfate-reducing bacteria(SRB)play an important role in the process of organic matter mineralization and formation of biogenic pyrite in lake and coastal sea sediments.Understanding how SRB respond to dissolved oxygen contents(D.O.)in fresh and coastal sea waters is essential to predict future evolution of mineralization under increased eutrophication and seasonal hypoxia.So far most pure cultures of sulfate reducing bacteria have been conducted under strict hypoxic conditions,in which SRB would gradually lose oxygen tolerance in the original habitat.In order to address how SRB respond to D.O.contents with co-existing bacteria,we collected water samples along the D.O.gradients and incubated them with D.O.concentrations strictly controlled the same as in situ.In such enrichment cultures,genera Desulfovibrio and Desulfomicrobium were the main sulfate-reducing bacteria,and genera Shewanella and Sulfurospirillum were the sulfur metabolism-related bacteria associated with SRB.The relative abundances of Desulfovibrio spp.decreased when D.O.concentration increased.The upper D.O.limit in our enrichment cultures was 6.68 mg/L,significantly higher than those previously reported in pure cultures or co-cultures,most likely resulted from the contribution of coexisting sulfur metabolism-related bacteria which may provide ecological niches for Desulfovibrio spp.by consuming residual oxygen.

关 键 词：硫酸盐还原菌 富集培养 DESULFOVIBRIO spp. 溶解氧 硫代谢相关菌 湖泊和沿海海域 

分 类 号：X172[环境科学与工程—环境科学]