Cultivation of methanogenic community from subseafloor sediments using a continuous-flow bioreactor
Cultivation of methanogenic community from subseafloor sediments using a continuous-flow bioreactor
复制标题
DOI：
10.1038/ismej.2011.64
复制
发表时间：
2011-12-01
期刊：
影响因子：
11
通讯作者：
Takai, Ken
中科院分区：
文献类型：
--
作者：
Imachi, Hiroyuki;Aoi, Ken;Takai, Ken
海底微生物产甲烷是地球碳循环的关键过程。然而，依赖于栽培的证据已经证明得很差。在这里，我们报告的培养产甲烷微生物财团从海底沉积物使用连续流型生物反应器与聚氨酯海绵作为微生物栖息地，称为下流悬挂海绵（DHS）反应器。我们在10 ℃的反应器中厌氧培养了从日本下北半岛收集的富含甲烷的岩心沉积物826天。向反应器中提供补充有葡萄糖、酵母提取物、乙酸盐和丙酸盐作为潜在能源的合成海水。经过289天的运行，微生物甲烷生产变得明显。荧光原位杂交分析显示，在反应器中的各种形态的代谢活性微生物细胞的存在。以16 S rRNA为目标的基于DNA和RNA的系统发育分析表明，在反应器中培养过程中，不同的微生物组分成功生长。反应器中的大多数生物类型，一旦产生甲烷，与培养序列的关系比与地下环境序列的关系更密切。与甲烷杆菌属，甲烷球菌属和甲烷八叠球菌属相关的潜在产甲烷菌类型主要检测伴随着甲烷生产，而未培养的古菌类型也被检测到。使用产甲烷菌群富集作为后续接种物，传统的分批式培养导致成功分离包括那些产甲烷菌在内的几种厌氧微生物。我们的研究结果证实，DHS的生物反应器是一个有用的系统，丰富了许多挑剔的微生物从海底沉积物，并将使以前未培养的海底微生物生命的纯培养物的生理和生态特征。The ISME Journal（2011）5，1913-1925; doi：10.1038/ismej.2011.64; 2011年6月9日在线发表
Microbial methanogenesis in subseafloor sediments is a key process in the carbon cycle on the Earth. However, the cultivation-dependent evidences have been poorly demonstrated. Here we report the cultivation of a methanogenic microbial consortium from subseafloor sediments using a continuous-flow-type bioreactor with polyurethane sponges as microbial habitats, called down-flow hanging sponge (DHS) reactor. We anaerobically incubated methane-rich core sediments collected from off Shimokita Peninsula, Japan, for 826 days in the reactor at 10 degrees C. Synthetic seawater supplemented with glucose, yeast extract, acetate and propionate as potential energy sources was provided into the reactor. After 289 days of operation, microbiological methane production became evident. Fluorescence in situ hybridization analysis revealed the presence of metabolically active microbial cells with various morphologies in the reactor. DNA-and RNA-based phylogenetic analyses targeting 16S rRNA indicated the successful growth of phylogenetically diverse microbial components during cultivation in the reactor. Most of the phylotypes in the reactor, once it made methane, were more closely related to culture sequences than to the subsurface environmental sequence. Potentially methanogenic phylotypes related to the genera Methanobacterium, Methanococcoides and Methanosarcina were predominantly detected concomitantly with methane production, while uncultured archaeal phylotypes were also detected. Using the methanogenic community enrichment as subsequent inocula, traditional batch-type cultivations led to the successful isolation of several anaerobic microbes including those methanogens. Our results substantiate that the DHS bioreactor is a useful system for the enrichment of numerous fastidious microbes from subseafloor sediments and will enable the physiological and ecological characterization of pure cultures of previously uncultivated subseafloor microbial life. The ISME Journal (2011) 5, 1913-1925; doi: 10.1038/ismej.2011.64; published online 9 June 2011