Screening and Biodegradation of Anaerobic Microorganisms for Nitrobenzene in Water

13 high efficiency bacterium strains were obtained from the activated sludge in waste water contaminated with nitrobenzene after 90 days intermittent aeration. MY4 was screened out in anaerobic condition, which was identified to be the most efficient bacteria strain. Further experiments were conducted on the biodegradation characteristics of MY4 strain. Results indicated that MY4 was Staphylococcus sp based on the 16S rRNA analysis. No obvious distinctions were observed in the biodegradation of nitrobenzene when MY4 strain concentration ranging from 104 to 107 CFU·mL-1. The degradation process was composed of three phases, among which the most rapid one was appeared in first 3 to 5 days. The high concentration of nitrobenzene could posed the negative effect on biodegradation, and the half life(t1/2·d-1)of nitrobenzene was prolonged with its concentration increased. The prominent product in biodegradation of nitrobenzene was determined to be aniline according to the results of GC-MS analysis.