Efficient Bioconversion of High Concentration Phytosterol Microdispersion to 4-Androstene-3,17-Dione (AD) by Mycobacterium sp. B3805

• Published in: Applied biochemistry and biotechnology Vol. 185; no. 2; pp. 494 - 506
• Main Authors: Mancilla, Rodrigo A., Little, Cedric, Amoroso, Alejandro
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2018; Springer Nature B.V
• Subjects: Androstenedione; Aqueous solutions; Bacteria; Bioavailability; Biochemistry; Bioconversion; biomass; Biotechnology; biotransformation; Chemistry; Chemistry and Materials Science; Complexity; Dispersion; Dispersions; Emulsions; glucose; homogenization; Microorganisms; Mycobacterium; particle size; phytosterols; solubility; Sterols; surfactants; Yeast; yeast extract; Bioconversion; AD; Phytosterols; Microdispersion; Steroids
• ISSN: 0273-2289; 1559-0291; 1559-0291
• DOI: 10.1007/s12010-017-2665-3

Low solubility of sterols in aqueous media limits efficient steroid production mediated by biocatalytic microorganisms such as Mycobacterium . Sterol emulsion technologies have been developed with low success rates, largely due to the complexity of generating stable and bioavailable particles. In this study, several aqueous dispersions of sterols in-water of different particle sizes were bioconverted to 4-androstene-3,17-dione (AD) in a solvent-free environment, using a classic microorganism Mycobacterium sp. B3805 as a model system. According to our results, the high concentration (20 g/L) phytosterol dispersions with the smallest particle size tested (370 nm) achieved up to 54% (7.4 g/L) AD production yield in 11 days. Moreover, the use of 0.1 biomass/sterols ratio in a complex bioconversion media containing yeast extract, and a 1:1 glucose/microdispersion ratio in the presence of the surfactant DK-Ester P-160 (HLB16), allowed homogenization and increased microdispersion stability, thus achieving the best results using emulsion technologies to date.