Microbial Genome Sequencing: Genomic Biodiversity in Hypersaline Environments

极端嗜盐古菌生活在盐度为3-5 M NaCl的盐水池中，在盐度、pH、温度、压力、营养物质等方面具有极强的多样性和动态性。除了它们特有的嗜盐性外，有些还具有嗜酸、嗜碱、嗜冷、嗜氧或轻微的嗜热性。极端嗜盐菌很容易在实验室中培养，并且是具有发达遗传工具的优秀实验系统。然而，到目前为止，只有一个来自极端嗜盐古菌，盐杆菌物种nrc -1的单一基因组被测序。为了研究极端嗜盐菌的基因组多样性，我们计划对具有高分辨率核糖体结构的代谢多功能嗜盐菌Haloarcula marismortui的基因组进行测序。如果时间和资源允许，将对不同的菌株进行额外的基因组分析，包括无色素的嗜碱菌亚洲白钠。深湖盐杆菌，一种能够在低至4摄氏度的温度下生长的嗜冷菌，Halosimplex carlsbadense，一种最近从二叠纪盐水包裹体中分离出来的可能古老的嗜盐菌，它似乎是一个遗传嵌合体，以及盐杆菌种GRB，一种与NRC-1密切相关的菌株。测序将在系统生物学研究所进行，注释将在马里兰大学生物技术研究所海洋生物技术中心进行。该项目将更好地了解极端嗜盐菌的生物多样性，包括基因组结构和进化、对极端环境的适应以及基因的横向转移。从长远来看，所提出的工作应该在生物技术方面提供新的应用，例如作物的工程耐盐性和新抗生素的开发。这是一个微生物基因组测序奖，由美国国家科学基金会和农业部未来农业和粮食系统倡议合作项目资助。

Extremely halophilic archaea inhabit brine pools containing 3-5 M NaCl, which areextraordinarily diverse and dynamic with respect to salinity, pH, temperature, pressure, nutrients,etc. In addition to their obligately halophilic character,some are also acidophilic, alkaliphilic,psychrophilic, barophilic, or slightly thermophilic. Extreme halophiles are easily cultured in thelaboratory and are excellent experimental systems with well-developed genetic tools. However,thus far, only a single genome from an extremely halophilic archaeon, Halobacterium speciesNRC-1, has been sequenced. In order to study the genomic diversity of extreme halophiles, weplan to sequence the genome of Haloarcula marismortui, a metabolically versatile halophile witha high-resolution ribosome structure. If time and resources permit, additional genomic analysiswill be conducted on diverse strains, including Natrialba asiatica, a non-pigmented alkaliphile.Halorubrum lacusprofundi, a psychrophile capable of growing at temperatures down to 4oC,Halosimplex carlsbadense, a likely ancient halophile recently isolated from a Permian brineinclusion, which appears to be a genetic chimera, and Halobacterium species GRB, a closelyrelated strain to NRC-1. Sequencing will be conducted at the Institute for Systems Biology andannotation will be done at the University of Maryland Biotechnology Institute, Center of MarineBiotechnology. This project will provide better understanding of biodiversity among extremehalophiles, including genome structure and evolution, adaptation to extreme environments, andlateral gene transfer. In the long term, the proposed work should provide novel applications inbiotechnology, e.g. engineering salt tolerance in crop plants and development of new antibiotics. This is a Microbial Genome Sequencing Award funded through a collaborative program between the National Science Foundation and the Department of Agriculture Initiative for Future Agriculture and Food Systems.