Environ Exp Biol (2019) 17: 193–199

Enhanced lindane degradation in the presence of root exudates of Acorus calamus and plant growth promoting rhizobacteria Ochrobactrum sp. strain A15

Abstract

Lindane is a toxic and bioaccumulative organochlorine pesticide. Its extensive use resulted in environmental contamination and need for bioremediation. In the present study bacterium identified as Ochrobactrum sp. strain A15 exhibited highest percentage degradation (83.7% of 10 mg L^–1 lindane) within 15 days. Lindane biodegradation efficiency of this strain increased by 10.7% in the presence of root exudates of Acorus calamus. Also, the average lindane biodegradation rate increased and its half-life decreased, when supplemented with root exudates. Ochrobactrum sp. A15 showed indole acetic acid production, hydrogen cyanide production, ammonia production, phosphate solubilization and 1-aminocyclopropane-1-carboxylate deaminase activity. Presence of pesticide had a negative effect on hydrogen cyanide production ability and decrease in indole acetic acid production and phosphorus production. No effect on 1-aminocyclopropane-1-carboxylate deaminase activity and ammonia production activity by bacteria was observed in the presence of lindane. Therefore, the combination of A. calamus and Ochrobactrum sp. strain A15 has the intrinsic capability to remove lindane and to support plant growth in the existence of lindane and this combination can be exploited for bioremediation of lindane.