Effect of microencapsulated cell preparation technology and conditions on the catalytic performance of Penicillium purpurogenum Li-3 strain cells

• The microencapsulated cell technology was firstly used in the bioconversion of glycyrrhizin.
• The Penicillium purpurogenum Li-3 cells were encapsulated in polyelectrolyte complex capsules.
• Sodium alginate and chitosan were used for the preparation of microcapsules.
• Microencapsulated cell possessed comparatively high mechanical strength and stability.

Microencapsulated cell preparation technology was applied to the hydrolysis of glycyrrhizin (GL) with Penicillium purpurogenum Li-3 whole-cell catalytic technology into glycyrrhetinic acid monoglucuronide (GAMG) possessing better bioavailability, sweetness, and security. The effect of the key techniques and technological conditions used for preparation of alginate–chitosan microencapsulated P. purpurogenum Li-3 strain cell on its usability was investigated. Results showed that technological conditions were crucial for microencapsulated cells to play the best. After cells were microencapsulated, mass transfer efficiency decreased slightly, resulting in a small decrease in catalytic activity. However, the cells obtained valid protection following microencapsulation, and thus exhibited better growth. Moreover, after continuous use for 12 batch cycles, 50.11% residual activity of the microencapsulated cells remained, and the breakage rate of microcapsules was only 6.4%. Therefore, microencapsulated P. purpurogenum Li-3 strain cells possessed comparatively high mechanical strength and stability.