Isolation and Biological Characterization of Tributyltin Degrading Bacterial from Onne Port Sediment

Abstract

Marine sediments collected from Onne Port, Rivers State Nigeria were manually polluted with tributyltin chloride (TBTCl) to evaluate the abilities of bacterial isolates to degrade the pollutant. Bacterial isolates were screened with at varying concentrations of 3 mM, 5 mM, 7 mM, and 10 mM. Bacterial strains with outstanding capabilities of utilizing TBTCl were biochemically and molecularly characterized. The total bacterial counts varied from 42 × 10 2 to 64.4 × 10 2 cfu/g when plated on MSA only and the viable counts on MSA to 3 mM TBTCl and MSA + 5 mM TBTCl ranged from 22 × 10 1 to 38.5 × 10 2 cfu/g and 18 × 10 1 from 21.9 × 10 1 cfu/g respectively; however, the total viable count in MSA + 10 mM TBTCl ranged from 1.1 × 10 1 - 3.8 × 10 1 cfu/g. Statistically, total bacterial count varied significantly across the sample sites p < 0.05 (one-way ANOVA). The 2 isolates that showed distinctive growth in the presence of high concentration of TBTCl (10 mM) were molecularly identified as Pseudomonas aeruginosa , and Pseudomonas fluorescens. The 16 SrRNA sequence phylogenetic analysis using BLAST program showed that the isolates were proteobacteria. Since there are scanty works on the mechanisms of the degradation of organotin, it is then important that isolates that can tolerate organotin to a large extent can be used in the cleanup of organotin-contaminated site. Pseudomonas aeuroginosa and Pseudomonas fluorescens are candidates for the bioremediation of the contaminated site.