Aciduric Proteobacteria isolated from pH 2.9 soil.
Acidic (pH 2.9) soil was used as an inoculum to culture heterotrophic bacteria at pH values of 3-4. Four isolates were obtained; on the basis of 16S rDNA sequence, they were shown to be members of the beta- and gamma-Proteobacteria. The three isolates that were most closely related to Burkholderia spp. had simple nutritional requirements and could grow in glucose-mineral salts media; two of these used a broad array of organic substrates. The 16S rDNA sequence of the fourth isolate was most similar (96%) to Frateuria aurantia. The isolates were aciduric rather than acidophilic; their pH ranges for growth were approximately 3.5-8. Unlike many bacteria whose acid tolerance represents the capacity to survive acid exposure, these microorganisms carried out exponential growth at pH<4 and their growth rates at pH 3.9 ranged from 60 to 98% of those found at pH 7. The cell yields on glucose of two strains were identical at pH 4 and pH 7. The acidic soils appeared to contain a very diverse bacterial community as assessed by denaturing gradient gel electrophoresis fingerprinting of PCR amplicons of a portion of the 16S rDNA gene. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00203-002-0427-1.
Curtis
Patrick
P
Department of Biological Sciences, Purdue University, West Lafayette IN 47907, USA.
Nakatsu
Cindy H
CH
Konopka
Allan
A
D003470:Culture Media / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D020560:Proteobacteria / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D012988:Soil Microbiology; D013379:Substrate Specificity
D003470:Culture Media; D005947:Glucose