Biodegradation of cypermethrin by a newly isolated actinomycetes HU-S-01 from wastewater sludge

ABSTRACT

A new cypermethrin degrading strain was isolated from wastewater sludge using enrichment technique. On the basis of morphological, physiological, biochemical characteristics tests and 16S rDNA sequence analysis, the strain was determined to be a Streptomyces species, probably a strain of Streptomyces parvulus, so it was designated as Streptomyces sp. HU-S-01. The strain Streptomyces sp.HU-S-01 is aerobic and optimum growth temperature for the strain was found to be 26-28°C with initial pH range 6.0-9.0 and pH 7.5 was found to be the optimum. This strain can also completely degrade 3-phenoxybenzoic acid within 96 h at the concentration of 50 mg/L. The kinetic constants Vmax, Km, Kcat and Kcat/ Km of enzyme for cypermethrin were 1.236 micro mol/min, 6.418 micro mol/mL, 13.493 min and 2.102 mL/mol.min, respectively. The degradation products of cypermethrin were identified using gas chromatograph-mass spectrometric [GC-MS] analysis. The degradation pathway followed by HU-S-01 involves oxidative as well as hydrolyzing. Biodegradation ability of strain Streptomyces sp. HU-S-01 without toxic byproducts reveals its potential for further study as a biological agent for the remediation of soil, water or crops, contaminated with cypermethrin