Isolation and ars detoxification of arsenite-oxidizing bacteria from abandoned arsenic-contaminated mines.
The ecosystems of certain abandoned mines contain arsenic-resistant bacteria capable of performing detoxification when an ars gene is present in the bacterial genome. The ars gene has already been isolated from Pseudomonas putida and identified as a member of the membrane transport regulatory deoxyribonucleic acid family. The arsenite-oxidizing bacterial strains isolated in the present study were found to grow in the presence of 66.7 mM sodium arsenate (V; Na2HAsO4.7H2O), yet experienced inhibited growth when the sodium arsenite (III; NaAsO2) concentration was higher than 26 mM. Batch experiment results showed that Pseudomonas putida strain OS-5 completely oxidized 1 mM of As(III) to As(V) within 35 h. An arsB gene encoding a membrane transport regulatory protein was observed in arsenite-oxidizing Pseudomonas putida strain OS-5, whereas arsB, arsH, and arrA were detected in strain OS-19, arsD and arsB were isolated from strain RW-18, and arsR, arsD, and arsB were found in E. coli strain OS-80. The leader gene of arsR, -arsD, was observed in a weak acid position. Thus, for bacteria exposed to weak acidity, the ars system may cause changes to the ecosystems of As-contaminated mines. Accordingly, the present results suggest that arsR, arsD, arsAB, arsA, arsB, arsC, arsH, arrA, arrB, aoxA, aoxB, aoxC, aoxD, aroA, and aroB may be useful for arsenite-oxidizing bacteria in abandoned arsenic-contaminated mines.
Arsenic Geoenvironment Laboratory (National Research Laboratory), Department of Environment Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
Jin-Soo
JS
Chang
In-Ho
IH
Yoon
Kyoung-Woong
KW
Kim
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000633:toxicity; D001149:Arsenates / Q000378:metabolism; D018053:Arsenites / Q000378:metabolism* / Q000633:toxicity*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D017753:Ecosystem; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D005798:Genes, Bacterial; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D010802:Phylogeny; D016958:Pseudomonas putida / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
D000900:Anti-Bacterial Agents; D001149:Arsenates; D018053:Arsenites; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; C015001:arsenite; C025657:arsenic acid