Abstract

A triazophos (TAP)-degrading bacterial strain, Klebsiella oxytoca TDB-1, which could use TAP as sole carbon source, was isolated by enrichment culture technology. The growth characteristics of strain TDB-1 with pressure of TAP were tested, and the results show that optimum growth condition was at 30°C, pH 8 and 2% (v/v) inoculation. Strain TDB-1 was great promise in TAP biodegradation for extreme pH tolerance (pH 4 and 10). The kinetic of strain TDB-1 in degrading TAP followed first-order model under optimal growth conditions. Cell surface hydrophobicity (CSH) assays of strain TDB-1 reflected that the strain TDB-1 was of higher hydrophobicity while grown on higher concentration of TAP. The growth and TAP-biodegradation characteristics of strain TDB-1 revealed that it would be an excellent alternative degrader for bioremediation of TAP contaminants, especially for that with extreme pH, such as some industrial wastewaters.

Key words: Biodegradation, triazophos, Klebsiella oxytoca TDB-1, cell surface hydrophobicity.