A repeat-batch membrane bioreactor with a phase inversion for the desaturation of isopropyl palmitate by a mutant...

Area of Science:

• Biotechnology
• Microbial Biotransformation
• Chemical Engineering

Background:

• Developing efficient bioconversion processes is crucial for sustainable chemical production.
• Rhodococcus species are known for their metabolic versatility and biotransformation capabilities.
• Optimizing reaction conditions and product recovery is key for industrial viability.

Purpose of the Study:

• To develop a novel repeat-batch membrane bioreactor for the bioconversion of isopropyl hexadecanoate to isopropyl cis-6-hexadecenoate.
• To optimize the bioconversion process using a Rhodococcus mutant.
• To establish an efficient product recovery method.

Main Methods:

• Utilized a repeat-batch membrane bioreactor with a Rhodococcus mutant.
• Optimized nutrient addition (glutamate, thiamine, MgSO(4)) to enhance bioconversion rate, yield, and cell activity.
• Employed a phase inversion technique (O/W to W/O emulsion) for product recovery using a hydrophobic hollow-fiber module.
• Repeated the batch reaction over 300 hours with spontaneous emulsion re-inversion.

Main Results:

• Achieved efficient bioconversion of isopropyl hexadecanoate to isopropyl cis-6-hexadecenoate.
• Demonstrated improved bioconversion rate and yield with specific nutrient supplementation.
• Successfully implemented a continuous product recovery system via phase inversion and membrane filtration.
• Maintained desaturation activity over multiple cycles (>13 repetitions, >300 h).
• Obtained a highly purified product using the urea adduct procedure.

Conclusions:

• The developed repeat-batch membrane bioreactor system is effective for the continuous production of isopropyl cis-6-hexadecenoate.
• Nutrient optimization and phase inversion are critical for enhancing process efficiency and product recovery.
• This approach offers a sustainable and scalable method for microbial biotransformation.