LEXEN: Paleobiology of Ancient Salt Formations: Examination of Primary Crystals for Biological Materials

9714203弗里兰这一建议是基于极端嗜盐细菌和/或大分子(生物材料)可以在氯化钠晶体内长时间保存的假设。该项目有三个目标：1)对各种古代地质盐岩进行采样，并清楚地记录样品的年龄；2)从目标1中获得的晶体中温和地提取和研究生物材料；3)通过实验测试各种生物材料在盐晶体中的稳定性。这项研究将通过增加对极端环境中原始生物的性质、它们繁衍的早期极端环境的性质以及微生物对地球早期环境的影响的科学理解，来推进NSF的几个Lexen计划。这个项目的研究将在最初的假设下进行，即寻找现存生物材料的最佳地点将是在至少200微米见方的初级充满流体的包裹体内部。目前，已经为该项目选择了四个样本点。它们包括：现代130万年(Ma)或更少的沉积盐，含有二叠纪盐类的地层(约250 Ma)，含有泥盆纪时代盐类的地层(约360-400 Ma)，以及第四个志留纪时代的遗址(430 Ma)。对于这个项目来说，最关键的问题是明确确定用于分离生物材料的每个晶体样品的年龄和质量。对单个样本进行年龄测定基本上需要两个层面的工作来收集数据。这些级别是：对周围晶体的微化石分析，将在艾伯塔省德拉姆赫勒皇家泰雷尔博物馆的Dennis Braman博士指导下进行；以及对提取的包裹体卤水进行化学分析，将在橡树岭国家实验室Juske Horita博士的指导下完成。生物采样将在项目主任(Russell H.Vreeland博士)的实验室进行。对生物材料的取样涉及使用表面灭菌的初级晶体，这些初级晶体将使用无菌技术渗透。将使用显微操纵器和消毒毛细管对夹杂物进行采样，这样可以在不破坏晶体的情况下提取样本。该项目将提供下列领域的重要数据：1)证实生物材料可以在晶体内生存很长一段时间；2)开发和测试从矿物包裹体中分离古老、脆弱的生物材料的程序；3)提供可用于确定2.5亿至4.3亿年前地球上微生物进化状态的生物材料；4)提供可用于在死亡已久的行星上搜索地外生命的数据和采样方法(DeVincenzi，1992，DeVincenzi等人)。5)将已证实的完整生物材料的存活期延长了10倍1.5-2.0x107(Cano和Borucki，1995)至2.5-4.3x108年。项目主任实验室一直在积极进行几项相关实验，为这一项目做准备。弗里兰博士研究嗜盐细菌的生态学、分类学和生理学已有近25年的历史。在过去的十年里，他一直参与地下盐层的采样工作。他发表了25篇主要研究出版物，并拥有一项涉及嗜盐细菌的专利。

9714203 Vreeland This proposal is based on the hypothesis that extremely halophilic bacteria and/or macromolecules (biological materials) can be preserved for long periods of time inside of NaCl crystals. This project has three objectives: 1) To sample a variety of ancient geologic salt formations and to clearly document the ages of the samples; 2) To gently extract and study biological materials from the crystals obtained in objective #1; 3) To experimentally examine the stability of various biological materials inside of salt crystals. This research will advance several of the NSF's LExEN program by increasing the scientific understanding of the nature of primitive organisms from extreme environments, the nature of the early extreme environment in which they thrived and the influence of microorganisms on the Earth's early environment. This project research will be conducted under the initial assumption that the best place to find extant biological materials will be inside primary fluid filled inclusions that are at least 200 microns square. At this time, four sample sites have been selected for this project. These include: depositional salts from the modern era 1.3 Million years of age (Ma) or less, a formation which contains Permian salt (ca 250 Ma); a formation containing Devonian age salt (ca. 360-400 Ma); and a fourth site made of Silurian age (430 Ma). The most critical issue for this project is to clearly establish the age and quality of each crystal sample used for the isolation of biological materials. Age dating the individual samples will basically involve collecting data at two levels of effort. These levels are: microfossil analyses of surrounding crystals, which will be performed under the direction of Dr. Dennis Braman at the Royal Tyrrel Museum in Drumheller, Alberta; and chemical analysis of the extracted inclusion brines which will be accomplished under the direction of Dr. Juske Horita at Oak Ridge National Laboratories. The biological sampling will be performed in the laboratory of the project director (Dr. Russell H. Vreeland). The sampling for biological material involves the use of surface sterilized primary crystals, which will be penetrated using aseptic techniques. The inclusions will be sampled using a micromanipulator and sterilized capillary tubes that will allow the sample to be withdrawn without destroying the crystal. This project will provide significant data in the following areas: 1) Demonstrated that biological materials can survive inside crystals for very long periods of time; 2) Developed and tested procedures for isolating ancient, fragile biological materials from mineral inclusions; 3) Provided biological material that can be used to determine the evolutionary state of microorganisms 250 to 430 million years B.P.E; 4) Provided data and sampling methods that can be used in a search for extraterrestrial life on long dead planets (DeVincenzi, 1992, DeVincenzi et al. 1990); 5) Pushed back the envelope for proven survival of intact biological materials by a factor of 10 1.5-2.0 x 107 (Cano and Borucki, 1995) to 2.5-4.3 x 108 years . The project director's laboratory has been actively conducting several relevant experiments in order to prepare for this project. Dr. Vreeland has studied the ecology, taxonomy and physiology of halophilic bacteria for nearly twenty-five years. He has been involved in sampling underground salt formations for the last ten years. He has published twenty-five primary research publications and has one patent dealing with halophilic bacteria.