Degradation of lindane by microorganisms. Evaluation of inhibitory effect on microbial activity using radiorespirometry

The degradation of U-14C-lindane in two type of Egyptian soil was studied under laboratory conditions. The rate of mineralization of lindane was slow. Evolution of 14CO2 increased with time and amounted to 3.5-5.5% of the initial concentration within 90 days. At this period both soil types contained about 88% of the applied radiocarbon; 33-37% of the initial dose being bound to the soil. The methanol 14C-extractables showed by TLC and HPLC analysis the presence of lindane as main product together with traces of minor metabolites. In addition, the effect of different rates of application of lindane on the respiratory activity of soil microorganisms was evaluated using U-14C-glucose as substrate. Concentrations up to 5 mgkg-1 caused a short term suppression of 14CO2 evolution. A dose of 10 mgkg-1 significantly inhibited soil respiration as determined by 14Co2 evolution for the 11 day period of the experiment. (author). 8 refs, 6 figs, 3 tabs