title: Improvement of AD Biosynthesis Response to Enhanced Oxygen Transfer by Oxygen Vectors in Mycobacterium neoaurum TCCC 11979.
abstract: In steroid biotransformation, soybean oil can improve the productivity of steroids by increasing substrate solubility and strengthen the cell membrane permeability. However, little is known of its role as oxygen carrier and its mechanism of promoting the steroid biotransformation. In this work, soybean oil used as oxygen vector for the enhancement of androst-4-ene-3,17-dione (AD) production by Mycobacterium neoaurum TCCC 11979 (MNR) was investigated. Upon the addition of 16% (v/v) soybean oil, the volumetric oxygen transfer coefficient (KLa) value increased by 44%, and the peak molar yield of AD (55.76%) was achieved. Analysis of intracellular cofactor levels showed high NAD+, ATP level, and a low NADH/NAD+ratio. Meanwhile, the two key enzymes of the tricarboxylic acid (TCA) cycle, namely, isocitrate dehydrogenase and α-ketoglutarate dehydrogenase, were upregulated after incubation with soybean oil. These enhancements induced by the increasing of oxygen supply showed positive effects on phytosterol (PS) bioconversion. Results could contribute to the understanding of effects of soybean oil as oxygen vector on steroid biotransformation and provided a convenient method for enhancing the efficiency of aerobic steroid biocatalysis.
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Liqiu
authors.initials: L
authors.lastname: Su
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China. shenyb@tust.edu.cn.
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Tian
authors.initials: T
authors.lastname: Gao
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Jianmei
authors.initials: J
authors.lastname: Luo
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China. minw@tust.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
mesh_terms: D000730:Androstadienes / Q000378:metabolism*; D000735:Androstenedione / Q000378:metabolism*; D001711:Biotransformation / Q000187:drug effects; D002952:Citric Acid Cycle / Q000187:drug effects; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D009161:Mycobacterium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D013024:Soybean Oil / Q000494:pharmacology
chemical_list: D000730:Androstadienes; D000735:Androstenedione; D013024:Soybean Oil; D010100:Oxygen
keywords: Androst-4-ene-3,17-dione; Cofactors; Mycobacterium neoaurum; Oxygen vector; Phytosterol