Selective desulfurization of dibenzothiophene by newly isolated Corynebacterium sp strain P32C1

Corynebacterium sp. strain P32C1 was selected from 30 strains isolated from soil samples of various areas in Iran on the basis of the ability to utilize dibenzothiophene (DBT) as a sole source of sulfur. During 27 h of cultivation in a jar-fermenter, DBT with an initial concentration of 0.25 mM was completely converted to 2-hydroxybip henyl (2HBP). Concentration change of 2'-hydroxybiphenyl-2-sulfinate (HBPS) during cultivation showed the general characteristics of reactions in series, DBT --> HBPS --> 2HBP. With resting cells prepared in late exponential phase, DBT of 0.5 mM was completely converted to 2HBP during 30 min, and the maximum specific production rate of 2HBP was 37 mmol/(kg dry cells h). Fed-batch addition of DBT in the jar-fermenter resulted in growth continuing up to a high 2HBP concentration of 0.4 mM. Desulfurization ability of P32C1 strain was compared with Rhodococcus sp. IGTS8 as a standard strain, and it was thought that P32C1 strain had a higher desulfurization activity. (C) 2000 Elsevier Science S.A. All rights reserved.