N-nitrosodimethylamine (NDMA) is a potential carcinogen that is produced as a disinfection by-product of chloramination or chlorination process in water and wastewater treatment systems. The ability of the dioxygenase-expressing bacteria, Rhodococcus sp. strain L4, to degrade NDMA after induction with cumene was examined in the presence and absence of its potential precursors. Dimethylamine (DMA), aniline (AN) and humic acid (HA) were selected as the precursors. The induced bacteria were able to degrade NDMA from initial concentrations ranging between 1 and 10 mg L⁻¹ to an undetectable level (< 0.24 µg L⁻¹) while there was no degradation of NDMA by the corresponding non-induced strain. The specific first-order degradation rate of NDMA ranged from 0.337 to 0.426 μg g-protein⁻¹ h⁻¹. Successful removal of all precursors was achieved by the induced bacteria. The presence of DMA had no negative effect on NDMA degradation. In contrast, a lag period was observed for the degradation of NDMA when AN or HA was present (except for the presence of 0.1 mg L⁻¹ AN). In the presence of all precursors, NDMA degradation was negatively affected by the increased concentration (from 1 to 10 mg L⁻¹) of all precursors.

中文翻译：

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异丙苯诱导的红球菌降解N-亚硝基二甲基胺及其胺前体。L4株。

N-亚硝基二甲胺（NDMA）是潜在的致癌物质，是水和废水处理系统中氯化或氯化过程的消毒副产物。表达双加氧酶的细菌红球菌的能力。在存在和不存在其潜在前体的情况下，检测了用枯烯诱导后降解NDMA的菌株L4。选择二甲胺（DMA），苯胺（AN）和腐殖酸（HA）作为前体。诱导的细菌能够将NDMA从最初的浓度范围从1到10 mg L ^-1降解到不可检测的水平（<0.24 µg L ^-1），而相应的非诱导菌株不会降解NDMA。NDMA的特定的一级降解速率为0.337至0.426μgg-蛋白^-1  h ^-1。通过诱导细菌成功去除了所有前体。DMA的存在对NDMA的降解没有负面影响。相反，当存在AN或HA（除了存在0.1mg L ^-1 AN时），观察到NDMA降解的滞后期。在所有前体的存在下，NDMA降解受到所有前体浓度增加（从1到10 mg L ^-1）的不利影响。