ROW: Anaerobes and Anaerobic Processes in Marine Microbial Assemblages: Zooplankton Digestive Tracts as a Model System

海洋环境中许多重要的微生物过程是厌氧的。固氮、硫酸盐还原、产甲烷和许多微量元素的利用只是厌氧细菌或只有在厌氧条件下才有活性的酶介导的几个过程。有矛盾的证据表明，厌氧过程发生在水柱中，具有厌氧微生物活动的化学特征，如海水中存在的甲烷峰。这些厌氧微生物组合在哪里？厌氧菌或厌氧过程如何在含氧良好的水柱中发生？与海洋浮游动物消化系统相关的微生物组合可能是水体厌氧过程的重要微环境。从微生物学的角度来看，肠道代表了水体高氧低营养环境中的高营养低氧环境。固氮和产甲烷是两个代谢要求很高的过程，它们需要大量的碳和能量来源，这些可以在海洋浮游动物的消化道中提供。这个ROW计划奖的主要目标是为海洋浮游动物肠道微生物群中的厌氧菌和厌氧过程的生理和生态研究选择一种模式生物。其中一个直接的目标是调查海洋浮游动物的肠道内容物，以估计在各种浮游动物肠道内发现的细菌的丰度和变异性，并选择合适的候选物种进行进一步研究。肠道厌氧菌和厌氧过程研究成功的关键将是使用严格的厌氧技术，这一程序尚未在其他海洋厌氧菌研究中常规使用。* * *

9415688 Proctor Many important microbial processes in the marine environment are anaerobic. Nitrogen fixation, sulfate reduction, methanogenesis and the availability of many trace elements are but a few of the processes which are mediated by either anaerobic bacteria or enzymes which are active only under anaerobic conditions. There is paradoxical evidence that anaerobic processes occur in the water column with chemical signatures of anaerobic microbial activity such as methane peaks present in marine waters. Where are these anaerobic microbial assemblages? How can anaerobes or anaerobic processes occur in a well-oxygenated water column. Microbial assemblages associated with the digestive systems of marine zooplankton may be important microenvironments for anaerobic processes in the water column. From a microbiological point of view, the gut represents a high nutrient, low oxygen environment within the high oxygen but low nutrient environment of the water column. Nitrogen fixation and methanogenesis are two of the metabolically- demanding processes which require large sources of carbon and energy that could be supplied in the digestive tracts of marine zooplankton. The primary goal of this ROW planning award is to select a model organism for a physiological and ecological study of anaerobes and anaerobic processes in the gut microflora of marine zooplankton. One of the immediate objectives is to survey the gut contents of marine zooplankton in order to estimate the abundance and variability of bacteria found within the gut of a variety of zooplankton and select a suitable candidate species for further study. The key to success in this study of gut anaerobes and anaerobic processes will be the use of strict anaerobic technique, a procedure which has not been routinely used in other studies of marine anaerobes. ***