A Strain Of Nitro Aniline Degradation Bacteria Isolation And Its Degradation Characteristics Identification

p-nitroaniline is a toxic dye intermediates and a chemical by-products, p -nitroaniline is very stable and difficult to be degraded in environment conditions. If it is discharged without treatment, it will seriously pollute the environment, p -nitroaniline related environmental problems have attracted a great attention from many scientists.Several methods have been used to remove p-nitroaniline contaminants from water, such as physical, chemical and biological treatment method. Biological treatment process has become a preferring way. One of the main attractions of using bacteria for p-nitroaniline degradation is that, unlike other chemical treatment methods, no second-time pollution is produced. In the biological treatment process of wastewater, however, because of aniline unique refractory, find efficient bacteria are a problem. This requires that these bacteria have a strong degradation of the ability to better adapt to the impact of load changes, enhance degradation of the efficiency of p-nitroaniline. In the present study, the p-nitroaniline removal under different conditions is investigated using batch methods. The effects of varying parameters such as pH, initial p-nitroaniline concentration and temperature on p-nitroaniline removal from aqueous solution were also investigated in detail.The article takes cultivation of high efficient bacteria as research object. A bacterium strain that degrades p-nitroaniline (PNA) was isolated from activated sludge of wastewater treatment plant treating wastewater from chemical factory. Results indicated this strain took p-nitroaniline as sole carbon, nitrogen and energy sources. It was identified as Microbacterium sp. PNA8 according to its morphology, and biochemical properties, and 16SrDNA sequence analysis. Further study indicated the optimum pH and temperature for cell growth and p-nitroaniline degradation were 7.0 and 28℃, respectively, and the optimal concentration of p-nitroaniline in four days was 80mg/L. Strain PNA8 growth and p-nitroaniline degradation was considerably faster in the presence of yeast extract.