NICKEL AND ACETOGENIC AUTOTROPHIC METABOLISM

意义：产乙酸菌在细菌的流动过程中起着重要作用 厌氧生境中的碳和能量，包括人类 胃肠道。乙酸菌独特的自养途径 被称为乙酰辅酶A(或木材)途径，研究表明 乙酰化是一个基本的生物学过程。新的和多样化的 最近已经阐明了乙酸菌的代谢活动， 包括从芳烃中提取碳和能量的能力 化合物。这些潜力可能有助于生存和 乙酸菌在其原生生境中的相互作用。总体而言， 芳香族化合物的厌氧代谢还没有明确的定义，而且 这些底物的产乙酸代谢很可能与整体 木质素和其他芳香族底物的生物转化，包括 芳香族有毒废物。 研究计划摘要：严格定义解决环境 产乙酸菌的代谢潜力已经被开发出来， 芳香族化合物的乙酰化中心的新的酶系统 已经被发现了。该项目的主要目标将是进一步 解决这些新实现的催化活性。经典的乙酸根 人类胃肠道分离株--热醋酸梭菌 产酸消化链球菌和其他产乙酸菌将被用于 学习。方法将包括：对碳和碳的流动进行酶分析 芳香族化合物中的还原剂.13C和14C示踪分析.高 高效液相色谱分析；高分辨率FAST 蛋白质液相色谱(FPLC)在酶纯化中的应用 系统；以及使用酶特异性抗体作为分子探针和 抑制剂。 具体目标包括： (1)解决所观察到的新能力的特殊性和多样性 用于芳香族化合物的乙酸化反应。 (Ii)阐明从芳香族衍生的碳和还原剂是如何 取代基用在乙酰辅酶A途径中。 (Iii)涉及的新酶系统的提纯和性质 在这些过程中。

Significance: Acetogenic bacteria play important roles in the flow of carbon and energy in anaerobic habitats, including the human gastrointestinal tract. The unique autotrophic pathway used by acetogens is termed the acetyl-CoA (or Wood) pathway, and studies have shown that acetogenesis is a fundamental biological process. New and diverse metabolic activities have recently been elucidated for acetogens, including the capacity to derive both carbon and energy from aromatic compounds. These potentials may contribute to the survival and interaction of acetogens in their native habitats. In general, the anaerobic metabolism of aromatic compounds is poorly defined, and the acetogenic metabolism of such substrates is likely coupled to the overall biotransformation of lignin and other aromatic substrates, including aromatic toxic wastes. Abstract of Research Plan: Strictly defined environments for resolution of the metabolic potentials of acetogenic bacteria have been developed, and new enzyme systems central to acetogenesis from aromatic compounds have been discovered. The main goal of this project will be to further resolve these newly realized catalytic activities. The classic acetogen Clostridium thermoaceticum, the human gastrointestinal isolate Peptostreptococcus productus, and other acetogens will be used in this study. Methods will include: enzyme analyses on the flow of carbon and reductant from aromatic compounds; 13C and 14C tracer analyses; high performance liquid chromatographic (HPLC) analyses; high-resolution fast protein liquid chromatography (FPLC) for the purification of enzyme systems; and the use of enzyme-specific antibodies as molecular probes and inhibitors. The specific aims include: (i) Resolving the specificity and diversity of new capacities observed for acetogenesis from aromatic compounds. (ii) Elucidating how carbon and reductant which are derived from aromatic substituent groups are utilized in the acetyl-CoA pathway. (iii) The purification and characterization of new enzyme systems involved in these processes.