Pilot-scale whole-cell biocatalysis for the hydroxylation of cyclosporine derivative, FR901459, at higher concentrations by Lentzea sp. 7887 using soybean flour as a novel substrate dispersant

Strain improvement of Lentzea sp. 7887 for higher yield per unit volume on hydroxylation of cyclosporine derivative FR901459

“…In Table 1, M-1 showed 1.13-, 1.19-and 1.54fold higher conversion ratios than those of the wild-type strain in Experiments 1, 2 and 3, respectively, which indicated that M-1 was a suitable strain for bioreactions with higher substrate concentrations. As we reported previously, 4) bioconversion of FR901459 at concentrations >1.85 mM by the wild-type strain showed a low conversion yield, even with the substrate dispersant present, due to substrate inhibition. Experiment 3 was a trial for substrate conditions >1.85 mM (i.e.…”

“…To improve substrate diffusion, we have used soybean flour as a substrate dispersant, which increases the reaction rate up to 3-fold the substrate concentration (1.85 mM) and allows bioconversion of the substrate in a 3-L reactor. 4) The reaction rate and the conversion yield, however, decreased dramatically at FR901459 concentrations >1.85 mM because of substrate inhibition of the biocatalyst, which was reported in various P450 monooxygenases. 5) In this study, we aimed to increase yield per unit volume of the biocatalysis to supply efficiently AS1837812 for anti-HCV drug candidate production by addressing the aforementioned two challenges.…”

“…One of the two challenges of the bioprocess is a low conversion yield of AS1837812 (i.e. <40%) in the above bioreaction 4) due to the formation of the two major by-products, compounds 1 (1-hydroxide) and 6 (1,9-dihydroxide) illustrated in Fig. S1(A).…”

“…7887 in a flask (30 mL) are described in our previous report. 4) The bioreaction mixture for FR901459 hydroxylation in a 3-L reactor consisted of 1 M phosphate buffer (pH 5.0; 0.1 vol. ), Lentzea sp.…”

“…Bioconversion conditions and quantitative analytical methods for FR901459, AS1837812 and compounds 1 and 6 are described in our previous report. 4) Figure S1(B) shows that the bioconversion of FR901459 to AS1837812 (9-hydroxide) affords by-products, including compounds 1 (1-hydroxide) and 6 (1,9-dihydroxide).…”