Statistical optimization of biomass production and biodesulfurization activity of Rhodococcus erythropolis HN2

The production of a biocatalyst with high biodesulfurization (BDS)-efficiency has been studied. That was performed throughout the statistical optimization of different physicochemical parameters affecting the efficiency of a batch BDS-process of a model oil (1000 ppm dibenzothiophene in n-hexane) by the previously isolated Rhodococcus erythropolis HN2(accession no. KF018282). Several model equations (Gaussian, polynomial and exponential functions) were investigated to assess the relationships between the variable operating conditions and both cell growth and % BDS. Statistical optimization revealed approximately, 80% BDS-efficiency occurred at optimum operating conditions of pH6.69, reaction temperature 27.47 degrees C, initial inoculum size OD600 nm 0.1 (i.e. 3.73 x 10(4) CFU/mL) and mixing rate of 154.19 rpm.