Interspecies Metabolic Complementation in Geothermal Microbial Mats

地热微生物垫中的种间代谢互补

• 批准号: 0605301
• 负责人: Frank Robb
• 金额: --
• 依托单位: University of Maryland Biotechnology Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0605301&HistoricalAwards=false
• 关键词: Interspecies; Metabolic; Complementation; Geothermal; Microbial

This research will identify and sequence the genes responsible for anaerobic oxidation of carbon monoxide and related metabolism (e.g., hydrogen formation) within natural microbial ecosystems. Bacteria and Archaea obtain their energy and carbon from a very wide variety of sources. Some microbes can use carbon monoxide (highly toxic to humans) as both an energy source and a carbon building block for producing new biomass and cells. A subset of these microbes produces hydrogen gas in connection with consuming carbon monoxide. Very few hydrogen-producing carboxydotrophs have been isolated, but there are likely many microbes not yet cultured that have genes that encode for this metabolic capability. In this research, SIGEX (Substrate Induced Gene Expression -- a novel molecular biology technique) will be used to hunt down these genes from natural populations of microbes in a remote site, the Uzon Caldera, Kamchatka. Bulk DNA will be extracted from natural and laboratory cultures of microbial mats and sediments from hot spring environments. The DNA will then be cut into short pieces, cloned into a molecular reporter construct in E. coli, and screened for presence or absence of the genes of interest. This strategy will be based on the investigators' recently obtained genome sequence of carboxydotrophs from Yellowstone and Siberian hot springs. Genes that switch on in the presence of carbon monoxide will be sequenced, and the diversity of microbes with this metabolic activity will be assessed. Many of the genes for hydrogen production are closely associated with carbon monoxide oxidation genes and will track with this screening method. Environmental chemistry will be linked to genomic potential by using microelectrodes and scanning voltammetry to measure the chemical composition of the water bathing the microbial mats. This work will be one of the first studies to employ SIGEX for finding rare but environmentally and biotechnologically important genes. It will also broaden our understanding of hydrogen production through microbial carbon monoxide oxidation. The detection of such genes and examination of the enzymes encoded by these genes may eventually pave the way for engineered biocatalysts that would mimic the efficiency of the microbes in oxidizing carbon monoxide and producing hydrogen. If carbon monoxide sensitive genes are found to be widespread, as the investigators' hypothesis states, it could indicate that carbon monoxide is a very active component of the carbon cycle in microbial ecosystems. This research will support the interdisciplinary training of a graduate student (with a molecular biology background) and a postdoctoral fellow (with a geochemistry background). The work will be conveyed to the general public through a partnership with the San Francisco Exploratorium, a world-renowned science center that links art, science, and human perception.

这项研究将确定和测序负责一氧化碳厌氧氧化和相关代谢的基因（例如，氢形成）。 细菌和微生物从各种各样的来源获得能量和碳。 一些微生物可以使用一氧化碳（对人类有剧毒）作为能源和碳构件来生产新的生物质和细胞。 这些微生物的一个子集产生氢气与消耗一氧化碳有关。 很少有产氢的一氧化碳营养菌被分离出来，但可能有许多尚未培养的微生物具有编码这种代谢能力的基因。 在这项研究中，SIGEX（底物诱导基因表达-一种新的分子生物学技术）将被用来从偏远地区的微生物自然种群中寻找这些基因，堪察加半岛的Uzon Caldera。 大量DNA将从温泉环境中的微生物垫和沉积物的自然和实验室培养物中提取。 然后将DNA切成短片段，克隆到E. coli中，并筛选目的基因的存在或不存在。这一策略将基于研究人员最近从黄石公园和西伯利亚温泉获得的一氧化碳营养生物的基因组序列。 将对在一氧化碳存在下开启的基因进行测序，并评估具有这种代谢活性的微生物的多样性。 许多产氢基因与一氧化碳氧化基因密切相关，将用这种筛选方法进行跟踪。 环境化学将通过使用微电极和扫描伏安法来测量沐浴微生物垫的水的化学成分，从而与基因组潜力相关联。 这项工作将是利用SIGEX寻找稀有但在环境和生物技术上重要的基因的首批研究之一。 它也将拓宽我们对通过微生物一氧化碳氧化制氢的理解。 对这些基因的检测和对这些基因编码的酶的检查可能最终为工程生物催化剂铺平道路，这种催化剂将模拟微生物氧化一氧化碳和产生氢气的效率。 如果发现一氧化碳敏感基因广泛存在，正如研究人员的假设所述，这可能表明一氧化碳是微生物生态系统中碳循环的一个非常活跃的成分。 这项研究将支持一名研究生（具有分子生物学背景）和一名博士后研究员（具有地球化学背景）的跨学科培训。 这项工作将通过与旧金山弗朗西斯科探索馆的合作伙伴关系传达给公众，这是一个世界知名的科学中心，将艺术，科学和人类感知联系起来。