Isolation Of A Salt-tolerant Aniline-Degrading Bacterium And Study On The Characteristic Of Aniline Degradation

The strain for the biodegradation of aniline was successfully isolatedfrom industrial wastewater and identified as Dietzia natronolimnaeaJQ-AN on the basis of the phylogenetic analysis of16S rDNA genesequences and the physiological biochemical character. The16S rDNAsequence of Dietzia natronolimnaea JQ-AN was deposited in GenBankwith the accession number JN867323.D. natronolimnaea JQ-AN could utilize aniline as the sole carbon andnitrogen source, grew in an alkaline and high salinity environment underaerobic conditions. To investigate the characteristics of anilinebiodegradation by D. natronolimnaea JQ-AN, the mineral salt mediumscontained300mg/L aniline were used as the subjects. Based on theseresults, D. natronolimnaea JQ-AN could grow and degrade aniline at pH6.0~9.0, and showed highest activity at pH8.0. D. natronolimnaea JQ-ANcould tolerated the high salinity of8%NaCl (w/v), and had a well activityof aniline biodegradation in minimal medium (0-6%NaCl, w/v). Theoptimal salinity for microbial growth and aniline biodegradation was3%NaCl. Sodium acetate significantly improved microbial growth and anilinebiodegradation. The optimal concentration of sodium acetate was40mM,at which point the aniline degradation rate reached87%. However,ammonium chloride suppressed aniline biodegradation added as a nitrogensource. On the basis of the experiment datas and previous reports, aniline biodegradation was presumed as an ortho-cleavage pathway with catecholintermediate by strain JQ-AN.In order to investigate the characteristics of treating aniline wastewaterby D. natronolimnaea JQ-AN, different initial concentrations of simulatedaniline wastewaters were studied in a home-made bioreactor with aworking volume of2L at pH8.0and3%NaCl (w/v). Degradation of100%,93.48%and77.28%were obtained for aniline at100,350and500mg L-1after treating over6d,11d and11d at30°C, respectively. Biodegradationof simulated aniline wastewaters by D. natronolimnaea JQ-AN was fittedwell to Haldane function, and the correlation coefficients was0.96. Thecoefficient Vmax, Ksand Kiof Haldane function was1.5775d-1,192.43mg/L,636.60mg/L, respectively.