Spear John R, Ley Ruth E, Berger Alicia B, Pace Norman R
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, 347 UCB, Boulder, Colorado 80309, USA.
Biol Bull. 2003 Apr;204(2):168-73. doi: 10.2307/1543553.
The goal of this project is to describe and understand the organismal composition, structure, and physiology of microbial ecosystems from hypersaline environments. One collection of such ecosystems occurs at North America's largest saltworks, the Exportadora de Sal, in Guerrero Negro, Baja California Sur. There, seawater flows through a series of evaporative basins with an increase in salinity until saturation is reached and halite crystallization begins. Several of these ponds are lined with thick (10 cm) microbial mats that have received some biological study. To determine the nature and extent of diversity of the microbial organisms that constitute these ecosystems, we are conducting a phylogenetic analysis using molecular approaches, based on cloning and sequencing of small subunit (SSU) rRNA genes (16S for Bacteria and Archaea, 18S for Eukarya). In addition, we report preliminary results on the microbial composition of a laminated community that occurs in a crystallized gypsum-halite matrix in near-saturated salt water. Exposure of the interior of these large (kilogram) wet, endoevaporite crystals reveals a multitude of colors: layers of yellow, green, pink, and purple microbiota. To date, analyses of these two environments indicate the ubiquitous dominance of uncultured organisms of phylogenetic kinds not generally thought to be associated with hypersaline environments.
本项目的目标是描述和了解高盐环境中微生物生态系统的生物组成、结构和生理学。这类生态系统的一个集合出现在北美最大的盐场，即位于南下加利福尼亚州格雷罗内格罗的萨尔出口公司。在那里，海水流经一系列蒸发池，盐度不断增加，直至达到饱和并开始石盐结晶。其中几个池塘覆盖着厚厚的（10厘米）微生物垫，已经进行了一些生物学研究。为了确定构成这些生态系统的微生物的多样性的性质和程度，我们正在基于小亚基（SSU）rRNA基因（细菌和古菌为16S，真核生物为18S）的克隆和测序，采用分子方法进行系统发育分析。此外，我们报告了在近饱和盐水中结晶石膏 - 石盐基质中出现的层状群落的微生物组成的初步结果。这些巨大的（千克级）潮湿的内蒸发岩晶体内部呈现出多种颜色：黄色、绿色、粉色和紫色微生物群落层。迄今为止，对这两种环境的分析表明，未培养的系统发育类型生物普遍占主导地位，而这些类型通常被认为与高盐环境无关。
