RUI-Microbial Observatories: Diversity of Halophilic Bacteria and Geochemical Signatures in a Tropical Solar Saltern

已向Lilliam Casillas博士和Carmen Hernandez博士(波多黎各大学-Humacao分校)和Pieter Visscher博士(康涅狄格大学)提供赠款，以便在波多黎各的Cabo Rojo太阳盐场建立一个微生物观测站。由于该地点强烈的太阳辐射、高风速和盐度，Salterns为研究极端条件下的生命提供了极好的环境。利用分子工具，将确定在潮湿和干燥期间在该地点存在的不同的嗜盐(即嗜盐)生物。一旦鉴定出这种嗜盐菌，就会研究它们的一些代谢活动，如光合作用、有氧呼吸、硫酸盐还原和固氮。利用微电极，将研究蓝藻垫子中嗜盐细菌的原位活动及其对场地生产力的贡献。同时，将确定垫子的沉积物和盐池的水柱的化学和地质成分。这项研究的主要目的是了解各种生物、化学和地质过程如何协同作用来确定卡波罗霍的高盐度生态系统。这些研究将尽可能完整地描述加勒比海热带盐湖的化学和地质条件，并确定微生物在这一生态系统中的作用。加勒比海地区这类性质的研究十分有限。在获取场地微生物多样性的同时，预计将分离出具有新适应和/或生理学的新生物。将特别关注嗜盐微生物在生命繁盛所需的地球化学反应中的作用。由于高盐度环境自前寒武纪时代就已为人所知，对卡波罗霍盐湖的研究应该能揭示微生物及其副产品在过去如何可能对建立现在的生态系统做出贡献。

A grant has been awarded to Drs. Lilliam Casillas and Carmen Hernandez (University of Puerto Rico-Humacao) and Pieter Visscher (University of Connecticut) to establish a Microbial Observatory in the Cabo Rojo solar salterns of Puerto Rico. The salterns provide an excellent setting for the study of life under extreme conditions due to the intense solar radiation, high wind velocity and salinity at the site. Using molecular tools different halophilic (i.e. salt-loving) organisms present at the site during wet and dry periods will be identified. Once such halophiles have been identified, some of their metabolic activities such as photosynthesis, aerobic respiration, sulfate reduction and nitrogen fixation will be studied. Using microelectrodes, in situ activities of the halophiles in the cyanobacterial mats and their contributions to the productivity of the site will be studied. At the same time, the chemical and geological composition of the sediments of the mats and the water column of the salt ponds will be identified. The main goal of this research is to understand how the various biological, chemical and geological processes act in concert to define the hypersaline ecosystems of Cabo Rojo.These studies will provide a scenario, as complete as possible, of the chemical and geological conditions in a Caribbean tropical saltern and establish the role of microorganisms in this ecosystem. Studies of this nature in the Caribbean are limited. While accessing the microbial diversity of the site it is anticipated that new organisms with novel adaptations and/or physiologies will be isolated. Special focus will be placed on the role of halophilic microorganisms in the geochemical transformations required for life to flourish. As hypersaline environments are known to have existed since Precambrian times, study of the Cabo Rojo salterns should shed light on how microorganisms and their by products could possibly have contributed in the past to establish present ecosystems.