Valenzuela-Encinas César, Neria-González Isabel, Alcántara-Hernández Rocio J, Enríquez-Aragón J Arturo, Estrada-Alvarado Isabel, Hernández-Rodríguez César, Dendooven Luc, Marsch Rodolfo
Departamento de Biotecnología y Bioingeniería, Cinvestav, Campus Zacatenco, Apartado Postal 14-740, Mexico, DF 07360, Mexico.
Extremophiles. 2008 Mar;12(2):247-54. doi: 10.1007/s00792-007-0121-y. Epub 2007 Dec 21.
The soil of the former lake Texcoco is an extreme environment localized in the valley of Mexico City, Mexico. It is highly saline and alkaline, where Na+, Cl(-), HCO3(-) and CO3(2-) are the predominant ions, with a pH ranging from 9.8 to 11.7 and electrolytic conductivities in saturation extracts from 22 to 150 dS m(-1). Metagenomic DNA from the archaeal community was extracted directly from soil and used as template to amplify 16S ribosomal gene by PCR. PCR products were used to construct gene libraries. The ribosomal library showed that the archaeal diversity included Natronococcus sp., Natronolimnobius sp., Natronobacterium sp., Natrinema sp., Natronomonas sp., Halovivax sp., "Halalkalicoccus jeotgali" and novel clades within the family of Halobacteriaceae. Four clones could not be classified. It was found that the archaeal diversity in an alkaline-saline soil of the former lake Texcoco, Mexico, was low, but showed yet uncharacterized and unclassified species.
特斯科科湖旧址的土壤是一种极端环境，位于墨西哥墨西哥城的山谷中。它盐碱化程度很高，其中Na+、Cl(-)、HCO3(-)和CO3(2-)是主要离子，pH值在9.8至11.7之间，饱和浸提液的电导率为22至150 dS m(-1)。古菌群落的宏基因组DNA直接从土壤中提取，并用作模板通过聚合酶链反应（PCR）扩增16S核糖体基因。PCR产物用于构建基因文库。核糖体文库显示，古菌多样性包括嗜盐碱球菌属（Natronococcus sp.）、嗜盐碱栖湖菌属（Natronolimnobius sp.）、嗜盐碱杆菌属（Natronobacterium sp.）、嗜盐碱红菌属（Natrinema sp.）、嗜盐碱单胞菌属（Natronomonas sp.）、嗜盐栖热菌属（Halovivax sp.）、“盐渍嗜碱球菌”（Halalkalicoccus jeotgali）以及嗜盐杆菌科内的新分支。有四个克隆无法分类。研究发现，墨西哥特斯科科湖旧址盐碱土壤中的古菌多样性较低，但仍存在未鉴定和未分类的物种。
