Ecophysiology of Phototrophic Carbon Allocation and Partitioning in Marine Microbial Mats

9415985之前关于微生物垫群落碳(C)动态的研究涉及到对垫内外碳的量化。虽然这些研究增加了对海洋微生物垫集体C通量的认识，但它们没有考虑到海洋微生物垫由不同的生理和进化成分组成，包括细菌、蓝藻和真核微生物尿囊菌。这项研究将继续下一个合乎逻辑的步骤，即辨别微生物垫群落的各个组成部分对微生物垫碳预算的贡献。这项研究的特点是使用机械/功能方法来确定控制底栖微生物垫中关键过程的主要生物和生态生理因素。主要研究目标包括：1)阐明草席群落结构和功能的生态生理过程；2)揭示控制微生物草席群落相互作用的机制；3)鉴定物种和功能群演替。具体地说，这项研究将使用显微镜和高效液相色谱方法记录垫状光养和重氮养殖体的特性(分类类群)和丰度(现存量)的季节性变化。碳的固定和分配将使用14C、O2微电极、显微放射自显影和原位生长速率、主要生态生理因素(光、营养物质、空中暴露等)进行评估。调控碳的固定、分配和群落演替的机制将在一系列受控的垫子操作实验中进行评估。

9415985 Paerl Previous research on carbon (C) dynamics of microbial mat communities has involved the quantification of C in and out of the mats. While these studies have increased the knowledge of the collective C fluxes of marine microbial mats, they have failed to take into account that mats are composed of physiologically and evolutionary distinct constituents including bacteria, cyanobacteria and eukaryotic microallgae. This research will pursue the next logical step which is to discern the contributions to the C budget of microbial mats by the individual components of the mat community. The distinguishing feature of this research is the use of a mechanistic/functional approach for identifying the principal organisms and ecophysiological factors controlling the key processes in benthic microbial mats. Principal research objectives include: 1) elucidating the ecophysiological processes responsible for mat community structure and function, 2) revealing mechanisms controlling microbial mat consortial interactions, and 3) identifying species and functional group succession. Specifically the research will document seasonal changes in the identity (taxonomic groups) and abundance (standing stock) of mat phototrophs and diazotrophs using microscopy and HPLC methods. C fixation and allocation will be evaluated using 14C, O2 microelectrodes, microautoradiography and in situ growth rates, The primary ecophysiological factors (light, nutrients, sub aerial exposure, etc.) that regulate C fixation, allocation and community succession will be assessed in a series of controlled mat manipulation experiments.