광양만에서 TBTCl (Tributyltin Chloride) 내성세균의 분리 및 분해활성

BACKGROUND: Tributyltin chloride is among the most toxic compounds known for aquatic ecosystems. Microorganisms are responsible for removal of TBTCl. Nevertheless, only limited number of marine bacteria were investigated for biodegradation of TBTCl in Korea. METHODS AND RESULTS: The number of TBTCl resistant bacteria ranged from 2.5 x 10(3) to 3.8 x 10(3) cfu/mL in the seawater, and ranged from 3.2 x 10(5) to 9.1 x 10(5) cfu/g in the surface sediment, respectively. The morphological, physiological, and biochemical characteristics of TBTCl resistant bacteria were investigated by API 20NE and other tests. The most abundant species of TBTCl resistant bacteria were Vibrio spp. (19.2%), Bacillus spp. (16.2%), Aeromonas spp. (15.2%), and Pseudomonas spp. (13.1%), etc. Eleven TBTCl resistant isolates also had a resistance to heavy metals (Cd, Cu, Hg, and Zn). Among them, isolate T7 showing the strong TBTCl-resistance was selected. This isolate was identified as the genus Pantoea by 16S rRNA gene sequencing and designated as Pantoea sp. T7. In addition, this bacterium was cultivated up to the growth of 50.7% after 60 hrs at TBTCl concentration of 500 μM. TBTCl-degrading activity of Pantoea sp. T7 was measured by GC-FPD analysis. As a result of biological TBTCl-degradation at TBTCl concentration of 100 μM, TBTCl-removal efficiency of Pantoeasp. T7 was 62.7%after 40 hrs. CONCLUSION(S): These results suggest that Pantoea sp. T7 is potentially useful for the bioremediation of TBT contamination.