Isolation, identification, and fenvalerate-degrading potential of Bacillus licheniformis CY-012

Abstract

Strain CY-012 isolated from garden soil sprayed with pyrethroid pesticide was able to efficiently degrade fenvalerate. The bacterium was identified as Bacillus licheniformis based on its morphology, physiological and biochemical characteristics, and 16S ribosomal DNA gene analysis. Response surface methodology analysis showed that the optimum conditions for fenvalerate degradation were fenvalerate concentration of 44.04 mg L−1, pH 7.48, and ferric chloride concentration of 0.051% (w/v). Under these conditions, approximately 80.07% of fenvalerate was degraded within 60 h of incubation. Five metabolic compounds, including α-isopropyl-4-chlorobenzene acetic acid, 4-chlorobenzene acetic acid, 3-phenoxybenzyl alcohol, phenol and benzoic acid were detected during fenvalerate degradation and identified by gas chromatography–mass spectrometry. A possible degradation pathway of fenvalerate was proposed based on these identified metabolites. The results indicated that strain CY-012 could potentially be used to eliminate environmental contamination with pyrethroid insecticides.

Keywords

• Bacillus licheniformis
• fenvalerate
• biodegradation
• metabolites
• 3-phenoxybenzoic acid (3-PBA)
• ribosomal DNA (rDNA)
• response surface methodology (RSM)
• Luria–Bertani (LB)
• mineral medium (MM)
• high-performance liquid chromatography (HPLC)
• Plackett–Burman (PB)
• electron ionization (EI)