Optimization of submerged fermentation conditions for biosynthesis of ergothioneine and enrichment of selenium from Pleurotus eryngii 528

Ergothioneine and selenium are biologically active substances that maintain human health. In order to increase the content of ergothioneine and selenium in the submerged fermentation products of Pleurotus eryngii, the non-nutritive culture conditions of submerged fermentation were investigated. When the concentration of sodium selenite was 3 μg/mL, the selenum conversion efficiency (94.78%) was the highest and the dry weight was the highest. The pH value of culture medium, shaking speed, culture temperature, inoculation amount and culture time affected the dry weight of fermentation, the content of ergothionein and selenium. The optimal culture conditions were optimized by single factor experiment as follows: pH 5.5 (natural), rotation speed 180 r/min, culture temperature 26 °C, inoculation amount 10%, and culture time 7 d. Under these conditions, the dry weight of Pleurotus eryngii fermentation product was 38.97 g/L, the ergothioneine content was 39.42 mg/L, and the bioconversion efficiency of selenium reached 84.63%.