Abstract:A bacterial strain capable of utilizing p-nitroaniline as sole carbon source to growth was isolated from sewage sludge. This strain was identified as Microbacterium sp. PNA8 based on its morphology, physiological, biochemical properties and 16S rRNA sequence analysis. Results indicated that the optimal temperature and pH for cell growth and for p-nitroaniline degradation was 30°C and 7.0. Strain PNA8 growth and p-nitroaniline degradation was considerably faster in the presence of yeast extract. Optimum conditions, in the culture medium added to 0.4 g/L yeast extract, 0.3 mmol/L p-nitroaniline degradation rate to 100% in 4 days.