Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Research on Microbes
Microbiology Experts
Online Submission
Access Statistics

Site Visitors

blog tracking

Vol: 72, No:4 , 2006; Pages: 2856-2863

Bacillus Endospores Isolated from Granite: Close Molecular Relationships to Globally Distributed Bacillus spp. from Endolithic and Extreme Environments

Patricia Fajardo-Cavazos and Wayne Nicholson*

Room 201-B, Space Life Sciences Laboratory, Building M6-1025/SLSL, Kennedy Space Center,FL 32899.


As part of an ongoing effort to catalog spore-forming bacterial populations in environments conducive to interplanetary transfer by natural impacts or by human spaceflight activities, spores of Bacillus spp. were isolated and characterized from the interior of near-subsurface granite rock collected from the Santa Catalina Mountains, AZ. Granite was found to contain ~500 cultivable Bacillus spores and ~104 total cultivable bacteria per gram. Many of the Bacillus isolates produced a previously unreported diffusible blue fluorescent compound. Two strains of eight tested exhibited increased spore UV resistance relative to a standard Bacillus subtilis UV biodosimetry strain. Fifty-six isolates were identified by repetitive extragenic palindromic PCR (rep-PCR) and 16S rRNA gene analysis as most closely related to B. megaterium (15 isolates), B. simplex (23 isolates), B. drentensis (6 isolates), B. niacini (7 isolates), and, likely, a new species related to B. barbaricus (5 isolates). Granite isolates were very closely related to a limited number of Bacillus spp. previously found to inhabit (i) globally distributed endolithic sites such as biodeteriorated murals, stone tombs, underground caverns, and rock concretions and (ii) extreme environments such as Antarctic soils, deep sea floor sediments, and spacecraft assembly facilities. Thus, it appears that the occurrence of Bacillus spp. in endolithic or extreme environments is not accidental but that these environments create unique niches excluding most Bacillus spp. but to which a limited number of Bacillus spp. are specifically adapted.

Keywords:Bacillus Endospores,Endolithic,Extreme Environments,16S rRNA gene analysis,microorganims,Taxonomy.

Corresponding author: Tel (321) 861-3487; Fax (321) 861-2925.

E-mail: WLN@ufl.edu


Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution