Biodegradation of γ-Hexachlorocyclohexane (Lindane) and α-Hexachlorocyclohexane in Water and a Soil Slurry by a Pandoraea Species

• Published in: Journal of agricultural and food chemistry 2002-04, Vol.50 (9), p.2548-2555
• Main Authors: Okeke, Benedict C, Siddique, Tariq, Arbestain, Marta Camps, Frankenberger, William T
• Format: Article
• Language: English
• Subjects: Bacteria; Base Sequence; Betaproteobacteria - genetics; Betaproteobacteria - growth & development; Betaproteobacteria - metabolism; Biodegradation, Environmental; Hexachlorocyclohexane - metabolism; Molecular Sequence Data; Pandoraea; RNA, Bacterial - chemistry; RNA, Ribosomal, 16S - chemistry; Soil Pollutants - metabolism; Water Pollutants - metabolism
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf011422a

Isomers of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) were some of the most widely used pesticides. Despite reduction in their production and use, HCH isomers present a serious environmental hazard. In this study, two bacterial isolates (LIN-1 and LIN-3) that can grow on γ-HCH as a sole source of carbon and energy were isolated from an enrichment culture. In liquid cultures of LIN-1 and LIN-3, 25.0 and 45.5% removal of γ-HCH, respectively, were achieved in 2 weeks. LIN-3 was identified as Pandoraea sp. by 16S rRNA gene sequence analysis (99% identity). Pandoraea sp. substantially degraded both γ- and α-HCH isomers at concentrations of 10−200 mg L-1 in liquid cultures. After 8 weeks of incubation in liquid culture, 89.9 and 93.3% of the γ- and α-HCH isomers declined, respectively, at an initial concentration of 150 mg L-1. In soil slurry cultures of Pandoraea sp., simulating a soil slurry phase bioremediation treatment, substantial decreases in the levels of the HCH isomers were observed at concentrations of 50−200 mg L-1. After 9 weeks, 59.6 and 53.3% biodegradations of γ- and α-HCH isomers, respectively, were achieved at 150 mg L-1. Using two 23-mer oligonucloetide primers targeting the 330 bp region of the 16S rRNA gene of Pandoraea sp., an approximately 330 bp PCR product was successfully amplified from DNA templates prepared from bacterial colonies and soil slurry culture. This system provides a direct and rapid PCR-based molecular tool for tracking Pandoraea sp. strain LIN-3 in water and soils. These results have impplied implications for the treatment of soils and water contaminated with HCH isomers. Keywords: Biotechnology; bioremediation; pesticides; hexachlorocyclohexane isomers; lindane; Pandoraea sp.; PCR detection