T. Matsui et al., Optimization of the copy number of dibenzothiophene desulfurizing genes toincrease the desulfurization activity of recombinant Rhodococcus sp., BIOTECH LET, 23(20), 2001, pp. 1715-1718
Dibenzothiophene (DBT) degradation activity of recombinant Rhodococcus sp.
T09/pRKPP was increased by about 3.5-fold by introduction of the NAD(P)H/FM
N oxidoreductase gene (dszD), while DBT desulfurization activity remained t
he same with production of dibenzo[1,2]oxathiin-6-oxide, which was caused b
y insufficient activity of the last desulfurization step involving a desulf
inase. Introduction of an additional dsz operon resulted in a 3.3-fold incr
ease DBT desulfurization activity (31 mu mol g dry cell(-1) h(-1)) compared
with that of T09/pRKPP (9.5 mu mol g dry cell(-1) h(-1)). Furthermore, opt
imization of DBT at 25 mg l(-1) and glucose at 10 g l(-1), increased the to
tal DBT desulfurization activity 2- to 3-fold due to increases in the DBT d
esulfurizing specific activity and the final cell concentration.