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Solvent selection and productivity in multiphase biotransformation systems
1Department of Chemical Engineering, University of Illinois at Chicago 60607.
Biotechnology Progress
|March 1, 1994
Summary
Solvent choice impacts steroid biotransformation kinetics. Octane showed the least toxicity, and higher organic solvent ratios increased hydrocortisone production by Curvularia lunata cells.
Area of Science:
- Biotechnology
- Chemical Engineering
- Microbial Biotransformation
Background:
- Steroid biotransformation is crucial for pharmaceutical production.
- Multiphase reaction kinetics are complex and influenced by solvent properties.
- Curvularia lunata is utilized for steroid 11-beta hydroxylation.
Purpose of the Study:
- To investigate the effect of solvent choice on the kinetics of steroid biotransformation.
- To examine the impact of solvent properties on cellular toxicity and productivity.
- To optimize the multiphase biotransformation of Reichstein's substance S to hydrocortisone.
Main Methods:
- Utilizing Curvularia lunata cells for 11-beta hydroxylation of Reichstein's substance S.
- Conducting batch suspension cultures with varying organic solvents and phase ratios.
- Assessing cellular toxicity and hydrocortisone production rates.
- Analyzing reaction kinetics under different solvent conditions.
Main Results:
- Solvent miscibility correlated with increased cellular toxicity.
- Octane demonstrated the lowest toxicity to the biotransformation system.
- Hydrocortisone production was significantly higher (20x) during the growth phase compared to the stationary phase.
- Increased organic solvent phase ratio led to enhanced system productivity.
- Higher steroid reactant concentration in the system contributed to increased productivity.
Conclusions:
- Solvent selection is critical for optimizing multiphase biotransformation efficiency and minimizing toxicity.
- Octane is a suitable solvent for this specific steroid biotransformation process.
- Phase ratio and reactant concentration are key factors influencing hydrocortisone yield.
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