Steroid transformations by a strain of Arthrobacter oxydans incapable of steroid ring degradation

Abstract

Arihrobacter oxydans 317 which is able to bring about the complete degradation of 8-sitosterol was treated with acridine orange to obtain a plasmid cured strain Arthrobacter 31 7AL, incapable of producing steroid ring degradation. The strain was neither able to form 4-androstene-3,l 7-dione(AD) from 1-sitosterol nor to convert AD to 1,4-androstadiene-3,17-dione(ADD). It was, however, able to hydroxylate AD and ADD at the C-17 position to form testosterone and 1 ,Candrostadiene-l7~-0l-3-one respectively. The strain could grow on psitosterol presumably utilizing the degradation products of the sterol side chain. Partial degradation of the p-sitosterol side chain was demonstrated by the isolation of 27-norcholest-4-en-3,24-dione, a metabolic product of the side chain degradation. The existence of metabolic blocks in a further degradation of the side chain to AD, in 1,2-dehydrogenation and 9a-hydroxylation of the steroid ring structure was postulated.

Engineering Mycobacterium smegmatis for testosterone production

“…On the other hand, enzymatic reduction of AD to TS by 17b-HSD has also been described in different microorganisms , including bacteria (Schultz et al, 1977;Payne and Talalay, 1985;Sarmah et al, 1989;Liu et al, 1994;Egorova et al, 2002aEgorova et al, ,b, 2005, yeasts (Ward and Young, 1990;Singer et al, 1991;Długo nski and Wilma nska, 1998;Pajic et al, 1999), filamentous fungi (Kristan and Ri zner, 2012) and plants (Hamada and Kawabe, 1991). Moreover, a singlestep microbial transformation process has been reported for the production of TS from sterols using several Mycobacterium sp.…”

Biochemical and structural characterization of 3‐ketosteroid‐Δ1‐dehydrogenase, a candidate enzyme for efficient bioconversion of steroids

“…For example, 4‐androstene‐3,17‐dione (AD) is an important precursor in the synthesis of contraceptive agents, estrogen, and progestogen . Although steroid drugs are mainly manufactured by chemical synthesis in the pharmaceutical industry, biotransformation provides a cost‐effective alternative with less environmental impact . Various microorganisms can be exploited for biotransformation and the great diversity of microbial metabolic reactions represents a rich repository of desirable chemical modifications of steroids .…”

“…2,3 Although steroid drugs are mainly manufactured by chemical synthesis in the pharmaceutical industry, 2,4,5 biotransformation provides a cost-effective alternative with less environmental impact. [6][7][8][9][10] Various microorganisms can be exploited for biotransformation and the great diversity of microbial metabolic reactions represents a rich repository of desirable chemical modifications of steroids. 11-13 Δ 1 -dehydrogenation in steroids is one of the crucial modifications owing to the increasing biological activity and economic value of the resulting steroid derivatives, 14 in which 310 www.soci.org S Mao et al…”