Abstract:

In order to optimize the liquid fermentation medium formula of Pleurotus pulmonarius, the collected wild P. pulmonarius strain was used as experimental material, and the strain was determined as P. pulmonarius by molecular biology methods. The optimum carbon source, nitrogen source, inorganic salt and their mass concentrations in the liquid fermentation medium of the wild P. pulmonarius were screened by single factor test. Then, according to the results of single factor test, corn flour, soybean meal and MgSO₄·7H₂O were selected as the investigation factors, and the mycelial biomass of P. pulmonarius was used as the index. The liquid fermentation medium of P. pulmonarius was optimized by Box-Benhnken design. The results of single factor experiments showed that the optimum carbon source, nitrogen source and inorganic salt for liquid fermentation medium of wild P. pulmonarius were corn flour, soybean meal and MgSO₄·7H₂O, respectively. The results of Box-Benhnken design test showed that the fitting coefficient of response surface regression model could reach 0.968 4, and the optimal liquid fermentation medium formula of P. pulmonarius was corn flour 24.36 g·L^-1, soybean meal 9.98 g·L^-1, MgSO₄·7H₂O 2.66 g·L^-1. In the optimal medium, the theoretical biomass of P. pulmonarius mycelium was 11.15 mg·mL^-1, and the measured biomass was 11.09 mg·mL^-1.

Key words: Pleurotus pulmonarius, fermentation, carbon source, nitrogen source, inorganic salt, culture medium, biomass