DOM consumption by marine bacterioplankton: Is the Cytophaga-Flavobacter group important?

异养细菌在海洋的碳循环中发挥着核心作用，消耗相当于30？浮游植物初级生产力的60%。虽然我们已经了解了很多关于海洋中细菌的多样性，但很少有关于自然组合中特定细菌群的代谢功能的信息，因为很少有文化？独立研究将细菌群落结构和功能联系起来。特别是，有溶解有机物（DOM）消费的不同系统发育的细菌，一个重要的生态和地球化学作用的细菌在ocean.This study将确定一组细菌在DOM消费的作用，Cytophaga？风味组。我们的假设是噬纤维菌？在海洋DOM的消耗过程中，黄嘌呤基团起着核心作用。我们将解决以下问题：（1）是否噬纤维菌？黄细菌群在海洋浮游细菌丰度和生物量中占很大比例。(2)噬纤维菌？黄曲霉菌群消耗DOM化合物，支持大部分细菌生产，并包括大部分DOM输入？（3）是噬纤维菌吗？负责大部分测量的细菌生产的flavorimide组？文化？将使用独立的方法来分析河口和上升流环境中的群落，这些群落具有一系列DOM输入和细菌消耗。噬纤维菌的相对丰度？将使用荧光原位杂交（FISH）测定黄嘌呤基团。噬纤维菌对DOM化合物的摄取？将使用放射性标记的DOM化合物和显微放射自显影结合FISH（MICRO？FISH）。噬纤维菌的贡献？将通过确定哪些细菌群摄取“H”来将黄嘌呤群与细菌生产进行比较。胸苷和H？亮氨酸。DOM吸收是海洋碳循环的一个重要方面，因此确定哪些类型的细菌负责大部分细菌的生产和DOM消耗是更好地了解海洋碳循环的关键一步。

Heterotrophic bacteria play a central role in the carbon cycle of the oceans, consuming organic matter equivalent to 30?60% of phytoplankton primary production. Although we have learned much about the diversity of bacteria in the ocean, there is little information on the metabolic function of specific bacterial groups in natural assemblages as few culture?independent studies have linked bacterial community structure and function. In particular, there is little information on dissolved organic matter (DOM) consumption by different phylogenetic groups of bacteria, an important ecological and biogeochemical role of bacteria in the ocean.This study will determine the role of one group of bacteria in DOM consumption, the Cytophaga?Flavobacter group. Our hypothesis is that the Cytophaga?Flavobacter group plays a central role in DOM consumption in the ocean. We will address the following questions: (1) Does the Cytophaga?Flavobacter group comprise a large fraction of marine bacterioplankton abundance and biovolume? (2) Does the Cytophaga?Flavobacter group consume DOM compounds that support a large fraction of bacterial production and comprise much of the DOM input? and (3) Is the Cytophaga?Flavobacter group responsible for a large fraction of the measured bacterial production?Culture?independent approaches will be used to assay communities in estuarine and upwelling environments having a range of DOM input and consumption by bacteria. The relative abundance of the Cytophaga?Flavobacter group will be determined using fluorescence in situ hybridization (FISH). Uptake of DOM compounds by the Cytophaga?Flavobacter group will be determined using radiolabeled DOM compounds and microautoradiography coupled with FISH (MICRO?FISH). The contribution of the Cytophaga?Flavobacter group to bacterial production will be compared to other groups by determining which bacterial groups take up 'H?thymidine and 'H?leucine. DOM uptake is an important aspect of carbon cycling in the ocean, so determining which types of bacteria are responsible for the bulk of bacterial production and DOM consumption is a key step in developing a better understanding of the marine carbon cycle.