Transformation of triphenyltin by Eubacteria: Fate and effects in environmental system

Abstract

Organotins such as triphenyltin (TPT) form an important group of bio-environmental tin-substituted aromatic contaminants used in various industries. Anthropogenic activities have led to an increase in TPT concentrations in water, soil, sediments and organisms. Knowledge about the environmental concentrations of any chemical compound is required to understand its effects on the system. Presence of such compounds in the environment is a serious threat and danger for human health and aquatic organisms and these combinations are very resistant against degradation. The reduction of TPT compounds in polluted ecosystems is a function of physical (adsorption to suspended solids and sediments), chemical (chemical and photochemical degradation) and biological (uptake and biological degradation) removal mechanisms. In the present study, triphenyltin-transforming bacteria were isolated from polluted harbors by enrichment technique and their growth in presence of this substrate was investigated. Genus assignment of the 24 bacterial isolates indicated that the Gram-negative organisms belonged to Enterobacter, Pseudomonas and Vibrio, while Gram-positive organisms were identified as Bacillus, Staphylococcus and Streptococcus. Among all the isolates identified, Pseudomonas spp. were predominant and accounted for 48 % of the total bacterial isolates, followed by Bacillus (24 %), Vibrio (12 %), Staphyolococcus (8 %), Streptococcus (4 %)andEnterobacter (4 %). A non-fluorescent Pseudomonas sp. identified as Pseudomonas stutzeri by 16S rRNA analysis was found to be most potential isolate with the ability to transform ~ 65 % of TPT when grown in BSS-SG medium with 100 mg L<Sup>−1</sup> TPT. Such bacterial strains having capability of transforming and withstanding high concentration of pollutants will be useful in bioremediation