潘多拉菌LX-1菌株对二氯甲烷的降解特性研究

从某污水处理厂的活性污泥中分离筛选到一株能以二氯甲烷为唯一碳源和能源生长的好氧降解菌LX-1(Pandoraea pnomenusa LX-1).单因素试验表明,适宜菌株LX-1生长的pH和环境温度分别为7.0和35℃,培养基里添加1%的NaCl有助于LX-1的生长及对DCM的降解,二氯甲烷的最大耐受浓度达到了1500mg·L-1.菌株LX-1降解1mg二氯甲烷能产生0.8083mg Cl-和0.3838mg CO2,脱氯率和矿化率分别达到了96.8%和74.15%.培养液中可溶性有机碳含量随降解时间变化呈上升趋势,pH呈下降趋势,结合相关文献报道,推测菌株在代谢二氯甲烷的过程中产生了水溶性小分子酸类(如甲酸)等结构较为简单的有机物,它们最终将被矿化为CO2、H2O和细胞生物量.

Characteristics of dichloromethane degradation by Pandoraea pnomenusa LX-1

An aerobic bacterium Pandoraea pnomenusa LX-1 that was capable of utilizing dichloromethane(DCM) as the sole carbon and energy source was isolated from the activated sludge of a sewage treatment plant.The single-factor test showed that the optimum pH and temperature for LX-1 growth were 7.2 and 35 ℃,respectively,and the addition of 1 % NaCl could contribute to the growth as well as DCM biodegradation.Under the optimum growth condition,the maximum allowable concentration of DCM was 1500 mg · L-1.With DCM consumed 1 mg,0.8083 mg of chloride and 0.3838 mg of CO2 were produced,and 96.8% of dechlorination rate and 74.15% of mineralization rate were achieved.During the biodegradation process,the soluble organic carbon increased while the pH decreased.It was concluded that DCM was metabolized to some simpler soluble organic compounds(such as formic acid),which were finally mineralized to CO2,H2O and synthesized to cell biomass.