REU: Microbial Ecology of Anaerobic Cellulose Decomposition

这项研究的目标是推进 了解厌氧纤维素的微生物生态学 土壤和沉积物中的降解。 目前，人们所知甚少 复杂的微生物转化过程 在没有氧气和纤维素的情况下， 在陆地环境中产生的有机物质，二氧化碳， 甲烷 该项目的一个重要目标是制定方法， 识别、枚举和估计群体的活动， 土壤和沉积物中的厌氧纤维素分解细菌。 快速 RNA测序方法将用于16S核糖体测序 纤维素发酵细菌分离菌株的RNA。 序列将被比对以识别那些由以下序列共享的序列： 细菌群的成员。 寡核苷酸 与这些独特序列互补的探针将用作探针， 检测特定群体的存在和活动， 纤维素分解细菌在对照实验和 环境样品。 该项目的第二个目标是 用这些探针来研究纤维素分解活性， 在一个拟议的研究地点， 在马萨诸塞州中部。 最后一个目标是 纤维素发酵细菌来固定氮气 几株 土壤和沉积物中的细菌最近被证明 纤维素作为固定N2的能源。 株 纤维素发酵细菌分离的一部分， 项目，以及其他目前已知的菌株，将 检查固氮酶活性的存在，以便 确定固定N2能力的普遍性， 纤维素发酵细菌，从而奠定了基础， 在碳和氮循环之间建立重要联系 in natural自然environments环境. 这样的过程很可能是常见的 在许多自然系统中，它们可能是 重要的生物学过程。

The goal of the proposed research is to advance understanding of the microbial ecology of anaerobic cellulose degradation in soils and sediments. At present, little is known of the complex microbial processes responsible for the conversion in the absence of oxygen, of cellulose, the most abundantly- produced organic material in terrestrial environments, to CO2 and CH4. An important objective of the project is to develop methods to identify, enumerate, and estimate the activity of groups of anaerobic cellulolytic bacteria in soils and sediments. Rapid RNA sequencing methodology will be used to sequence 16S ribosomal RNAs of isolated strains of cellulose-fermenting bacteria. Sequences will be aligned to identify those that are shared by members of groups of bacteria. Oligodeoxynucleotides complementary to these unique sequences will be used as probes to detect the presence and activity of specific groups of cellulolytic bacteria in controlled experiments and in environmental samples. A second objective of the project is to use these probes to investigate the activity of cellulolytic bacteria in poorly-drained forest soil at a proposed study site in Central Massachusetts. A final objective concerns the ability of cellulose-fermenting bacteria to fix N2. Several strains of bacteria from soils and sediments have recently been shown to use cellulose as an energy source for the fixation of N2. Strains of cellulose-fermenting bacteria isolated as part of the proposed project, as well as additional presently known strains, will be examined for the presence of nitrogenase activity in order to determine the prevalence of the ability to fix N2 among cellulose-fermenting bacteria, thus setting the groundwork for establishing an important link between carbon and nitrogen cycles in natural environments. Such processes are likely to be common in many natural systems, where they may be indications of important biological processes.