Identification and biological characterization of an acetonitrile degrading strain

Abstract:

Abstract:［Objective］To identify and characterize an acetonitrile degrading strain BX2，thus to assess its potentials in the treatment of acetonitrile containing wastewater.［Methods］ By means of phenotype and physio-biochemical characterization as well as phylogenetic analysis，we identified strain BX2． The optimum culture conditions of the strain were studied with single factor test，and the degradation of acetonitrile under the optimal growth conditions was determined． Additionally， NaCl tolerance was investigated.［Results］ The phenotype and physio-biochemical characteristics of strain BX2 were similar to those of Rhodococcus sp. The phylogenetic analysis based on 16S rRNA， gyrB and secA1 gene suggested strain BX2 was the closest relative of Rhodococcus rhodochrous with 99.37%，99.29% and 97.87% sequence similarity respectively．The optimal conditions for cell growth were 35℃，initial pH 7.5，and 1% inoculum． Under these conditions，the degradation rate of acetonitrile was 95.87% (800mg/L) within 16 h.Strain BX2 was able to grow in defined medium containing NaCl up to 6%.［Conclusion］Strain BX2 was identified as Rhodococcus rhodochrous and named Rhodococcus rhodochrous BX2． It showed great environmental adaptation and high capability of degrading acetonitrile．