Enhancement of exopolysaccharide production from Ganoderma lucidum using a novel submerged volatile co-culture system.

Abstract

Based on the impact of volatile organic compounds (VOCs) on secondary metabolite pathways, a novel submerged volatile co-culture system was constructed, and the effects of thirteen fungal and bacterial VOCs were investigated on Ganoderma lucidum exopolysaccharides production. The results demonstrated at least a 2.2-fold increase in exopolysaccharide (EPS) specific production yield in 6 days submerged volatile co-culture of G.\xa0lucidum with Pleurotus ostreatus. Therefore, P.\xa0ostreatus was selected as a variable culture, and the effects of agitation speed, inoculum size, initial pH, and co-culture volume on EPSs production were investigated using a Taguchi L9 orthogonal array. Finally, the highest concentration of EPSs (3.35\xa0±\xa00.22\xa0g\xa0L-1) was obtained under optimized conditions; initial pH 5.0, inoculum size 10%, 150\xa0rpm, and 3:1 volume ratio of variable culture to main culture.