两株细菌对邻氯硝基苯的协同降解

在纯培养和水体模拟培养条件下,分别研究了对氯苯和硝基苯具有高效降解性能的两株土著菌Acinetobacter calcoaceticus和Pseudomonasputida对邻氯硝基苯的协同降解效果.结果表明,纯培养条件下不同菌悬液对邻氯硝基苯的降解能力大小顺序为:混合菌群PseudomonasputidaAcinetobacter calcoaceticus,培养6d后,混合菌群对邻氯硝基苯的降解率可达到94.5%;混合菌群降解邻氯硝基苯的过程中伴随着NO2-和Cl-的释放,且NO2-的释放早于Cl-,Cl-的总净释放量大于NO2-;葡萄糖的加入能显著促进菌体细胞的生长,降低亚硝酸根离子的积累,但未能显著提高邻氯硝基苯的降解效果.在水体模拟培养条件下,水相中邻氯硝基苯的去除主要依靠混合菌群的降解作用;底泥、鹅卵石及其表面附着的生物能明显促进邻氯硝基苯的去除;在相同条件下培养8d后,基质为底泥时邻氯硝基苯的去除效率可达92.5%,大于基质为鹅卵石时的去除率(85.5%).研究结果可为环境中邻氯硝基苯的去除提供新的途径.

Synergistic degradation of2-chloronitrobenzene by two strains of bacteria

Under the conditions of pure and simulated water body culture, two strains of indigenous bacteria Acinetobacter calcoaceticus and Pseudomonas putida, which are able to effectively degrade chlorobenzene and nitrobenzene respectively, were used to study synergistic degradation of 2-chloronitrobenzene. Results showed that the order of capacity to degrade 2-chloronitrobenzene was the mixture of two strains>Pseudomonas putida>Acinetobacter calcoaceticus. Under pure culture conditions, 94.5% of 2-chloronitrobenzene was degraded by the mixture of strains after 6 d of incubation. The degradation of 2-chloronitrobenzene was accompanied by the release of NO-2 and Cl-. The release of NO-2 was earlier than that of Cl-, but the total net released Cl- was more than that of NO-2. The addition of glucose significantly accelerated the growth of bacterial cells and decreased the accumulation of NO-2, but failed to promote the degradation of 2-chloronitrobenzene. In the conditions of simulated water body culture, the mixture of the strains played the main role in the removal of 2-chloronitrobenzene in the aqueous phase. The sludge, pebbles and organisms attached to the surface of pebbles obviously promoted the removal of 2-chloronitrobenzene. After 8 d of incubation, the removal rate of 2-chloronitrobenzene (92.5%) in the simulated system with sludge was larger than that in the simulated system with pebbles (85.5%). The findings of this research can provide a new pathway for the removal of 2-chloronitrobenzene in the environment.