Molecular Insight into Toxicant Degradation by Microbial Communities

描述(申请人提供)：微生物具有很大的生化潜力，能够利用天然和人为化合物作为生长和能源来源。它们对极端环境条件具有独特的适应性，在地球上随处可见。然而，众所周知，微生物的生物多样性仍然相对未被开发，环境中99%以上的细菌没有特征。烷烃降解菌是研究微生物生物多样性的范例模式系统，从环境修复和工业生物催化的角度来看，具有工业相关性的额外好处：烷烃降解菌在石油的生物降解中很活跃，它们的烷烃氧化酶在执行药物相关性的手性转化方面很有价值。从海洋、极地地区、土壤和污染地点分离出了独特的烷烃降解菌。最近，许多新的属和种被描述为基于分离出来的能够降解烷烃的生物。吉尔吉斯共和国代表了世界上一个栖息地多种多样的地区，从高山沙漠到永久积雪的山脉，重度盐碱和碱性土壤，石油和苏联时代遗留下来的重金属污染遗址，农田，山区森林和溪流，纯净的山谷，以及大片(100英里长40宽)中等盐碱度的山湖(伊塞克-凯尔湖)。这些环境还没有被系统地检查它们所拥有的微生物的多样性。本提案旨在探索吉尔吉斯共和国烷烃降解菌的微生物多样性，目的是找到吉尔吉斯共和国不同生境所特有的细菌和烷烃羟基酶基因并确定其特征。将采取分子生态学的方法，使用各种方法来检查直接从环境和增菌培养中提取的DNA。微生物多样性将以16S rRNA基因作为生物标志物进行监测，烷烃降解多样性将以二铁和细胞色素P450烷基单加氧酶基因为目标进行检测。该提案将吉尔吉斯共和国土壤微生物学科学家与罗格斯大学的教职员工结合在一起，他们在分解代谢途径的分子表征方面拥有丰富的经验。烷烃等燃料烃是环境中常见的污染物。接触这些化合物会影响人类的健康和福祉。在吉尔吉斯共和国等发展中国家和偏远国家，对参与修复这些化学品的微生物及其分子生态学的了解，在决定这些有毒化合物和其他有毒化合物的环境命运方面起着重要作用。通过这项拟议研究的互动活动，将提高吉尔吉斯共和国人民对污染危害的认识。

DESCRIPTION (provided by applicant): Microorganisms have a large biochemical potential, with the capability to use natural and anthropogenic compounds as growth and energy sources. They possess unique adaptability to extreme environmental conditions and are found everywhere on the Earth. However, it is well known that the biodiversity of microorganisms remains relatively untapped with more than 99% of all bacteria in the environment uncharacterized. The alkane degrading bacteria are example model systems for studying microbial biodiversity with the added benefit of industrial relevance from both the environmental remediation and industrial biocatalysis standpoints: alkane degrading bacteria are active in the biodegradation of petroleum and their alkane oxidizing enzymes are valuable in performing chiral transformations of pharmaceutical relevance. Unique alkane degrading bacteria have been isolated from the ocean, from the Polar Regions, from soil, and from polluted sites. Many new genera and species have recently been described based on organisms isolated for the ability to degrade alkanes. The Kyrgyz Republic represents a region of the world with varied habitats ranging from high mountain deserts, permanently snow-capped mountains, heavily saline and alkaline soils, petroleum and heavy metal polluted sites left over from the soviet era, agricultural fields, mountain forests and streams, pristine valleys, and a large (100 miles long by 40 wide) mildly saline mountain lake (Lake Issyk-Kyl). These environments have not yet been systematically examined for the diversity of microorganisms that they possess. The present proposal aims to explore the microbial diversity of alkane degrading bacteria in the Kyrgyz Republic with the aim of finding and characterizing bacteria and alkane hydroxylase genes that are unique to the varied habitats in the Kyrgyz Republic. A molecular ecology approach will be taken, using a variety of methodologies to examine DNA directly extracted from the environment and from enrichment cultures. Microbial diversity will be monitored using the 16S rRNA gene as a biomarker and alkane degrading diversity will be examined using diiron and cytochrome P450 alkane monooxygenase genes as the target. The proposal brings together Kyrgyz Republic soil microbiology scientists with faculty at Rutgers University who have extensive experience in the molecular characterization of catabolic pathways. Fuel hydrocarbons such as alkanes are common contaminants in the environment. Exposure to these compounds can affect human health and well being. Knowledge of the microorganisms which are involved in the remediation of these chemicals and their molecular ecology in developing and remote countries like the Kyrgyz Republic plays a major role in determining the environmental fate of these and other toxic compounds. Public awareness among the people of the Kyrgyz Republic of the hazards of pollution will be raised through the interactive activities of this proposed research.