U.S.-Korea Cooperative Research: Carbon Monoxide as a Substrate for Microbial Maintenance

0342779金细菌在全球一氧化碳（CO）排放中起着重要作用。 土壤和水生系统的水体中的大量未知细菌种群每年氧化数百太克，约占估计的大气年通量的10%-20%。 尽管他们的地球化学意义，相对知之甚少的身份CO氧化人口活跃在原地，其生物和生理多样性或重要性的CO作为底物，他们的基本代谢需要。一氧化碳氧化剂 很明显，高浓度（1000 ppm）的CO可以作为实验室培养的细胞碳和能量的唯一来源，但环境CO浓度很少达到或超过几ppm。 细菌很容易使用这样的浓度，但它们是否足以显著满足细胞代谢的需要？这个奖项支持教授加里M。金和他在缅因州大学的一个研究生与Y. M. Kim和他的研究小组来自韩国延世大学。他们将评估低的、生态上现实的CO浓度对两种常见土壤分离株（耻垢分枝杆菌和慢生型大豆根瘤菌）生长和存活的意义。 这个合作项目将包括分子和生理分析的能力，CO在低浓度下，以促进生存和生存能力的CO氧化剂在土壤中的自然动态相关的条件下。 Kim博士在分子生物学、包括分枝杆菌在内的CO氧化细菌的生理学和生长以及CO脱氢酶的遗传学和生物化学表征方面拥有丰富的经验，而King博士在研究微生物痕量气体利用的生态生理学和地球化学、分析技术和近环境CO分析仪器方面拥有丰富的经验，以及设计用于研究的微观世界和气流系统的专业知识。更广泛的意义这项研究的结果将显着提高我们对微生物CO代谢的生态生理学的理解，特别是在现实世界的水平。 这些信息是预测长期区域尺度气候、土地利用和水生系统富营养化扰动的潜在反应的重要因素。这项工作将涉及美国和韩国研究生的交流，他们将从学习新的研究技术和文化经验中受益。 国际研究经验可能会扩大金博士小组的美国学生未来的研究机会。 这种研究伙伴关系中的技术和方法交流将提高两个实验室解决影响大气成分的微生物群体生态生理学中的热点问题的能力。

0342779KingBacteria play an important role in the global budget of carbon monoxide (CO). Largely unknown bacterial populations in soils and the water column of aquatic systems oxidize hundreds of teragrams per year, or about 10%-20% of the estimated annual flux to the atmosphere. In spite of their biogeochemical significance, relatively little is known about the identity of CO-oxidizing populations active in situ, their phylogenic and physiological diversity or the importance of CO as substrate for their basic metabolic needs. of CO oxidizers. It is clear that CO at high concentrations ( 1000 ppm) can serve as a sole source of cell carbon and energy for laboratory-grown cultures, but ambient CO concentrations seldom reach or exceed a few ppm. Bacteria readily use such concentrations, but are they sufficient to contribute significantly to cellular metabolic needs?This award supports Professor Gary M. King and one of his graduate students at the University of Maine to collaborate in research on this question with Dr. Y. M. Kim and his research group from Yonsei University in Korea. They will evaluate the significance of low, ecologically realistic CO concentrations for growth and survival of two common soil isolates, Mycobacterium smegmatis and Bradyrhizobium japonicum. This collaborative project will include both molecular and physiological analyses of the ability of CO at low concentrations to promote the survival and viability of CO oxidizers under conditions relevant to their natural dynamics in soils. Dr. Kim has extensive experience with the molecular biology, physiology and growth of CO-oxidizing bacteria, including mycobacteria, and characterization of the genetics and biochemistry of CO dehydrogenase, while Dr. King has extensive experience in studying the ecophysiology and biogeochemistry of microbial trace gas utilization, analytical techniques and instrumentation for near-ambient CO analyses, and expertise in the design of microcosms and gas flow systems for research. Broader significanceResults of the study will significantly improve our understanding of the ecophysiology of microbial CO metabolism, particularly at real-world levels. This information is an important factor in predicting potential responses to long-term, regional-scale disturbances in climate, land use and eutrophication of aquatic systems.The work will involve exchanges of both U.S. and Korean graduate students, who will benefit from learning new research techniques and from the cultural experience. The international research experience is likely to expand the future research opportunities of the US students in Dr. King's group. The exchange of techniques and methods in this research partnership will enhance the capabilities of both labs to address topical issues in the ecophysiology of microbial groups that affect atmospheric composition.