Author(s): Gao B, Liu WB, Jia LY, Xu L, Xie J
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Abstract In this study, an Alcaligenes sp. strain DG-5 that can effectively degrade dichlorodiphenyltrichloro-ethanes (DDTs) under aerobic conditions was isolated from DDTs-contaminated sediment. Various factors that affect the biodegradation of DDTs by DG-5 were investigated. About 88 \%, 65 \% and 45 \% of the total DDTs were consumed within 120 h when their initial concentrations were 0.5, 5 and 15 mg L⁻¹, respectively. However, almost no degradation was observed when their concentration was increased to 30 mg L⁻¹, but the addition of nutrients significantly improved the degradation, and 66 \% and 90 \% of the total DDTs were degraded at 336 h in the presence of 5 g L⁻¹ peptone and yeast extract, respectively. Moreover, the addition of 20 mM formate also enhanced the ability of DG-5 to transform DDTs, and its DDT transformation capacity (T(c)) value was increased by 1.8 - 2.7 fold for the pure (p,p'-DDT or o,p'-DDT only) and mixed systems (p,p'-DDT, o,p'-DDT, p,p'-DDD and p,p'-DDE). Furthermore, it was found that competitive inhibition in the biodegradation by DDT compounds occurred in the mixed system.
This article was published in J Environ Sci Health B
and referenced in Journal of Bioremediation & Biodegradation