1Pesticide Residue Laboratory, Indian Institute of Horticultural Research, Hessaraghatta Lake P.O., Bangalore-560 089, Karnataka, India
2Division of Crop Protection, Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram-695 017, Kerala, India
3Mushroom Culture Laboratory, Indian Institute of Horticultural Research, Hessaraghatta Lake P.O., Bangalore-560 089, Karnataka, India
*Corresponding author E-mail: soudamini_mohapatra@rediffmail.com
Online published on 19 June, 2014.
Degradation of gamma-hexachlorocyclohexane (γ-HCH) was carried out using 4 species of Pleurotus namely P. florida, P. sajor-caju, P. citrinopileatus and P. ostreatus in Raper's complete broth. The broth containing the fungal cultures was amended with 100 and 500 μg of γ-HCH (@ 1 and 5 μg ml−1). In the initial stages degradation of γ-HCH was faster in P. florida inoculated broth compared to other cultures. However, after 30 d, complete degradation of γ-HCH was observed in all Pleurotus inoculated broth irrespective of its concentration. There was no adsorption of lindane by any of the fungal biomass. Absence of isomers and degradation products of lindane indicated complete mineralization of lindane by all the four Pleurotus species. Bioremediation of y-HCH was studied in soil by amending it with spent mushroom substrate (SMS) from P. florida inoculated paddy straw. Within 60 d about 70% γ-HCH degraded from SMS added soil compared to only 10% from soil without SMS. The half-life of degradation was 32 and 38 d in soil with SMS, 304 and 499 d in soil without SMS at the concentration of 1 and 5 μg g−1, respectively.
Biodegradation, gamma-HCH, isomers, metabolites, Pleurotus species
