Hydrocarbon-oxidizing potential and the genes for n-alkane biodegradation in a new acidophilic mycobacterial association from sulfur blocks

• Published in: Microbiology (New York) 2014-11, Vol.83 (6), p.764-772
• Main Authors: Ivanova, A. E., Sukhacheva, M. V., Kanat’eva, A. Yu, Kravchenko, I. K., Kurganov, A. A.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Experimental Articles; Life Sciences; Medical Microbiology; Microbiology; Mycobacterium
• ISSN: 0026-2617; 1608-3237
• DOI: 10.1134/S0026261714060095

The capacity of AG S10 , a new aerobic acidophilic (growing within the pH range from 1.3 to 4.5 with the optimum at 2.0–2.5) bacterial association from sulfur blocks of the Astrakhan gas-processing complex (AGC), for oxidation of hydrocarbons of various chemical structure was investigated. A broad spectrum of normal (C 10 -C 21 ) and iso -alkanes, toluene, naphthalene, and phenanthrene, as well as isoprenoids resistant to microbial degradation, pristane and phytane (components of paraffin oil), and 2,2,4,4,6,8,8,-heptamethylnonane, a branched hydrocarbon, were biodegraded under acidic conditions. Microbiological investigation revealed the dominance of mycobacteria in the AG S10 association, which was confirmed by analysis of the 16S rRNA gene clone library. In the phylogenetic tree, the 16S rRNA sequences formed a branch within the cluster of slow-growing mycobacteria, with 98% homology to the closest species Mycobacterium florentinum . Genomic DNA of AG S10 culture grown on C 14 -C 17 n -alkanes at pH 2.5 was found to contain the genes of two hydroxylase families, alk B and Cyp 153, indicating their combined involvement in hydrocarbon biodegradation. The high hydrocarbon-oxidizing potential of the AG S10 bacterial association indicated that further search for the genes responsible for degradation of various hydrocarbons in acidophilic mycobacteria could be promising.