Isolation, characterization and molecular identification of a halotolerant Bacillus megaterium CTBmeg1 able to grow on halogenated compounds

Abstract

Halogenated compounds pose long-term potential risks to the well-being of humans due to their recalcitrance and persistent toxicity. The quest for microorganisms capable of degrading such perilous substances merits urgent consideration. In this study, a new dehalogenase-producing bacterium was isolated from a hypersaline environment (TuzGölü Lake, Turkey), and identified as Bacillus megaterium strain CTBmeg1 (Accession number MK128900). Under culture conditions (pH 8.0, NaCl 20%, 30 °C, 200 rpm, 9 days), the B. megaterium strain CTBmeg1 showed an optimum growth on 10 mmol/L of 2,2-dichloropropionic acid with a doubling time of 26.41 h. Furthermore, the presence of a putative halotolerant dehalogenase gene (dehCTBmeg1) of B. megaterium strain CTBmeg1 was detected and amplified via PCR technique. Bio-prospecting for microorganisms in a highly saline environment capable of utilizing halogenated compounds as the sole carbon may prove to be a practical and safer means for bioremediation of contaminated coastal areas, an increasingly common place predicament faced by many nations.

Keywords

• biodegradation
• halogenated compounds
• 2,2-dichloropropionic acid
• dehalogenase
• bacillus megaterium
• hypersaline environments