biodegradation of para-amino acetanilide by halomonas sp. tbz3

Background: aromatic compounds are known as a group of highly persistent environmental pollutants. halomonas sp. tbz3 was isolated from the highly salty urmia lake of iran. in this study, characterization of a new halomonas isolate called halomonas sp. tbz3 and its employment for biodegradation of para-amino acetanilide (paa), as an aromatic environmental pollutant, is described.objectives: this study aimed to characterize the tbz3 isolate and to elucidate its ability as a biodegradative agent that decomposes paa.materials and methods: primarily, dna-dna hybridization between tbz3, halomonas denitrificans dsm18045t and halomonas saccharevitans lmg 23976t was carried out. para-amino acetanilide biodegradation was assessed using spectrophotometry and confirmed by gas chromatography-mass spectroscopy (gc-ms). parameters effective on biodegradation of paa were optimized by the response surface methodology (rsm).results: the dna-dna hybridization experiments between isolate tbz3, h. denitrificans and h. saccharevitans revealed relatedness levels of 57% and 65%, respectively. according to gc-ms results, tbz3 degrades paa to benzene, hexyl butanoate, 3-methyl-1-heptanol and hexyl hexanoate. temperature 32.92°c, ph 6.76, and salinity 14% are the optimum conditions for biodegradation with a confidence level of 95% (at level α = 0.05).conclusions: according to our results, halomonas sp. tbz3 could be considered as a biological agent for bioremediation of paa and possibly other similar aromatic compounds.