The high-efficient production of phelligridin LA by Inonotus baumii with an integrated fermentation-separation process.

The phelligridin LA was one of the valuable metabolites synthesized by the medicinal fungus Sanghuang in liquid fermentation. In the improvement of PLA productivity by fermentation, we investigated the optimal conditions for the efficient separation of PLA from the fermentation broth with a chromatographic column packed with the macroporous resin ADS-17. Based on the findings, we further developed an integrated bioreactor system that coupled the fermentation and separation of PLA. Fermentation experiments with the bioreactor system testified the performance of our design in fortification of the PLA production: an improvement of PLA production by 2.14 folds was successfully achieved due to the prompt removal of the PLA, while the formation of hyphae biomass was not affected. Also, the integrated system could afford a simultaneous purification of PLA to a purity of 92.95% with a recovery of 84.3%, which was comparable to that of the PLA purified with an additional process (97.53%), at a reasonable recovery. This study provided a feasible approach for the improved production of PLA by fermentation. Besides, the design of the integrated bioreactor system offered a useful reference for the fermentation process development of fungi for the production of diverse valuable metabolites.

Effective isolation of antioxidant Phelligridin LA from the fermentation broth of Inonotus baumii by macroporous resin.

Phelligridin LA (PLA) is a natural product with vigorous free radical scavenging activities accumulated in the liquid fermentation of herbal medicinal fungus Inonotus baumii. Aiming to establish an efficient isolation method of PLA from the fermentation broth, we evaluated the adsorption of PLA by macroporous resins. The best resin ADS-17 was screened for six candidates with various physical properties and adsorption behaviors. Studies on the thermodynamics and kinetics of the process revealed that the adsorption reaction could take place spontaneously, which implied that the heat generated in adsorption might compensate for the decrease in entropy. The Freundlich theory could be utilized to fit the experimental data. The pseudo-second-order equation could describe the process, and the adsorption rate was primarily controlled by liquid film diffusion and pore diffusion. The influencing operation factors (temperature, pH, and the ratio of fermentation broth to resin) of the adsorption process were optimized with response surface methodology. The optimized condition (temperature 22.81 °C, pH 5.19, and the ratio of fermentation broth to resin or RLS 5.11) supported an adsorption rate of 97.03%. These findings would be indispensable for further optimization of the efficient separation of PLA from the fermentation broth, and the fermentation production of PLA in which separation would be included.