西太平洋多金属结核区12个站位沉积物中可培养潜在腐殖质转化菌的多样性

【背景】海洋环境作为地球上最大的有机碳库贮藏着大量腐殖质，其中可能蕴藏着丰富的腐殖质转化菌。【目的】从深海沉积物环境中分离具有潜在腐殖质转化能力的细菌，为难降解天然有机多聚物的生物转化提供菌种资源。【方法】利用以腐殖质为唯一碳源的培养基，对西太平洋多金属结核区12个站位沉积物样品中的腐殖质转化菌进行富集培养和纯化，通过16S rRNA基因测序分析比对初步确定分离菌株的分类地位，并利用含苯胺蓝的培养基筛选潜在的腐殖质转化菌。【结果】从12个沉积物样品中共分离获得菌株276株，隶属于放线菌纲(Actinobacteria)、纤维粘网菌纲(Cytophagia)、黄杆菌纲(Flavobacteria)、 α变形菌纲(Alphaproteobacteria)和γ变形菌纲(Gammaproteobacteria)中的14个目37个属56个种(含1个潜在新属和2个新种)，其中49个种呈现木质素修饰酶阳性。【结论】利用以腐殖质为唯一碳源和能源的培养基可以分离获得具有较高多样性的潜在腐殖质转化菌。

Diversity of potential culturable humic substance- transforming bacteria in sediments from 12 stations in the western Pacific polymetallic nodule province

Background] The marine environment, as the largest organic carbon store on the earth, stores a large amount of humic substances, which may harbor abundant humic substance-transforming bacteria. Objective] To isolate potential humic substance-transforming bacteria from marine sediments, and provide bacterial resources for the biotransformation of refractory natural organic polymers. Methods] With humic substances as the sole carbon source, the humic substance-transforming bacteria in the sediment samples from 12 stations in the western Pacific polymetallic nodule province were enriched and purified. The taxonomic status of the purified bacteria was preliminarily identified by 16S rRNA gene sequence comparison. The potential humic substance-transforming bacteria were screened out by aniline blue-containing medium. Results] A total of 276 strains were isolated from 12 sediment samples, belonging to 56 species, 37 genera, 14 orders of Actinobacteria, Cytophagia, Flavobacteria, Alphaproteobacteria and Gammaproteobacteria, including 1 potential new genus and 2 new species. Of the 56 species, 49 species were lignin-modifying enzyme positive. Conclusion] The medium with humic substances as the sole carbon and energy source can be used to isolate potential humic substance-transforming bacteria with high diversity.