Solid-State Production of Beneficial Fungi on Apple Processing Wastes Using Glucosamine as the Indicator of Growth.

Three Trichoderma species, a Penicillium species, and a Rhizopus species were grown on apple pomace at 25 degrees C through solid-state fermentation. The effects of CaCO(3), water, and nitrogen sources on the growth of selected fungi on apple pomace were investigated. Soluble protein and glucosamine contents of fermented pomace were measured as the parameters of fungal growth. The maximum growth of all fungi was established on apple pomace supplemented with 0.05 g of CaCO(3), 2 mL of water, and 0.05 g of NH(4)NO(3) or 0.3 mL of fish protein hydrolysate per gram of pomace. The optimal water activity of the medium for fungal growth was 0.96 at 25 degrees C. This research has provided a clear indication for using glucosamine as a proper indicator of fungal growth in heterogeneous solid-state systems. It also shows potentials for bioconversion of apple processing wastes by beneficial fungi into valuable bioinoculants that are being targeted for agricultural and environmental applications.