環(huán)境基因組學使我們對真實世界中微生物的認識發(fā)生了革命性變化,但該學科并不是關于微生物在實驗室獲得的“克隆”培養(yǎng)中的行為的,。本期Nature報告了“實驗環(huán)境基因組學”的一個新穎的例子,,涉及創(chuàng)建一個由從美國佐治亞州Sapelo島附近收集到的海水構成的微型生態(tài)環(huán)境,。對該體系的操縱表明,這個沿海微生物群落被能利用多種有機化合物的代謝性泛食微生物所支配,,而不是被專門代謝溶解的有機碳中某一特定成分的細菌菌種所支配,。這一發(fā)現(xiàn)對于識別碳循環(huán)相關過程的分類—功能關系及對于海洋生物地球化學預測模型的構建都具有重要意義。
英文原文:
Nature 451, 708-711 (7 February 2008) | doi:10.1038/nature06513; Received 20 September 2007; Accepted 30 November 2007; Published online 27 January 2008
Bacterial carbon processing by generalist species in the coastal ocean
Xiaozhen Mou1, Shulei Sun1, Robert A. Edwards2, Robert E. Hodson1 & Mary Ann Moran1
Department of Marine Sciences, University of Georgia, Athens, Georgia 30602, USA
Department of Computer Science, San Diego State University, San Diego, California 92182, USA
Correspondence to: Mary Ann Moran1 Correspondence and requests for materials should be addressed to M.A.M. (Email: [email protected]).
Abstract
The assimilation and mineralization of dissolved organic carbon (DOC) by marine bacterioplankton is a major process in the ocean carbon cycle1. However, little information exists on the specific metabolic functions of participating bacteria and on whether individual taxa specialize on particular components of the marine DOC pool2. Here we use experimental metagenomics to show that coastal communities are populated by taxa capable of metabolizing a wide variety of organic carbon compounds. Genomic DNA captured from bacterial community subsets metabolizing a single model component of the DOC pool (either dimethylsulphoniopropionate or vanillate) showed substantial overlap in gene composition as well as a diversity of carbon-processing capabilities beyond the selected phenotypes. Our direct measure of niche breadth for bacterial functional assemblages indicates that, in accordance with ecological theory, heterogeneity in the composition and supply of organic carbon to coastal oceans may favour generalist bacteria. In the important interplay between microbial community structure and biogeochemical cycling, coastal heterotrophic communities may be controlled less by transient changes in the carbon reservoir that they process and more by factors such as trophic interactions and physical conditions.