Isolation and ars Detoxification of Arsenite-Oxidizing Bacteria from Abandoned Arsenic-Contaminated Mines

• Published in: Journal of microbiology and biotechnology Vol. 17; no. 5; pp. 812 - 821
• Main Authors: Chang, Jin-Soo, Yoon, In-Ho, Kim, Kyoung-Woong
• Format: Journal Article
• Language: Korean
• Published: 한국미생물생명공학회 30.05.2007; 한국미생물·생명공학회
• Subjects: abandoned mine; ars Detoxification; arsenite-oxidizing bacteria; 생물학; arsenite-oxidizing bacteria; ars; abandoned mine; Detoxification
• ISSN: 1017-7825; 1738-8872

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($V;\;Na_2HAsO_4{\cdot}7H_2O$), yet experienced inhibited growth when the sodium arsenite($III;\;NaAsO_2$) 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.