Microbial transformation of hydrophobic compound in cloud point system

Microbial transformations of hydrophobic compounds are often constrained by practical difficulties, such as substrate solubility and product inhibition. A novel approach, microbial transformation in cloud point system (CPS), was developed. The system could provide microbial cells with aqueous environment and could dissolve Substrate and products in surfactant phase. A microbial transformation of cholesterol to androst-1,4-diene-3,17-dione (ADD) and androst-4-ene-3,17-dione (4-AD) has been carried out in the system consisting of nonionic surfactants Triton X-100 and Triton X-114, which is more effective than the microbial transformation in conventional media. The biocompatibility and bioavailability in the cloud point system were investigated by determination of solubilization of surfactant phase and observation of dilute phase and coacervate phase under microscopy. The system parameters of microbial transformation were optimized. It indicated that CPS has the potential capability to be utilized as an effective microbial transformation medium. (C) 2003 Elsevier B.V. All rights reserved.