Isolation of tributyltin chloride (TBT) resistance microbes and determination of microbial organotin degradation activity by GC-MS

Organotin compounds including tributyltin chloride (TBT) have been extensively employed in a variety of industrial products, such as antifouling paints for ships, wood preservatives, biocides, and plastic stabilizers. A... [ view full abstract ]

Organotin compounds including tributyltin chloride (TBT) have been extensively employed in a variety of industrial products, such as antifouling paints for ships, wood preservatives, biocides, and plastic stabilizers. A comprehensive literature review has indicated that TBT is the most toxic compound known to aquatic ecosystems. The widespread use of TBT, has resulted in severe environmental problems around the world, including endocrine disruptions of aquatic life. TBT can bond to suspended material and is deposited in benthic sediments, where it can last unaltered for decades. In recent years, biological degradation has been suggested to be the major pathway for the removal of TBT from the estuarine and marine sedimentary environment compared to physicochemical methods such as thermal treatment, steam striping and chemical oxidation. In this study, TBT resistance bacteria were isolated from a variety of sediments and soil samples using TBT containing media. A number of assays took place to assess the suitability of the microorganism strains such as their resistance to TBT and the strains ability to utilise TBT as a sole carbon source via GC-MS over a period of 21 days. Successful candidate microorganisms were phylogenetically identified using 16rRNA sequence analysis. Results show 54% of the bacterial isolates were resistant to TBT. In addition six isolates have the ability break down TBT to its less toxic species monobutyltin (MBT) and dibutyltin (DBT). Consequently the six isolates have the potential to be used in a remediation assay of sediment or soil with minimal disruption to the local environment.