Effects of radiation and NRSP on the fermentation of cellulosic waste by selective fungi

Abstract

The feasibility of natural rubber serum powder(NRSP) as a nutritional additive was studied on the fermentation of sugar cane bagasse by Pleurotus sajor-caju, Pleurotus flavellatus, Coprinus phlytidosprorus and Volvariella volvacea after irradiation to degrade cellulosic material effectively and produce useful resources such as economical animal feed and mushrooms. The effects of radiation, NRSP concentration, pH, growth medium and the other additive were investigated observing fungal growth in PDA(Potato Dextrose Agar) plate, dry matter weight, protein concentration and filtration ability in liquid state fermentation, finally protein concentration, organic matter and crude fiber change in solid state fermentation. First of all, the PDA(potato dextrose agar) plate experiment was performed to investigate the feasibility of NRSP as a nutritional source for mushroom growth. The growth rate of P. sajor-caju, P. flavellatus and C. phlytidosprorus were increased with increasing NRSP concentration without pH adjustment and with pH 6. The maximum growth ratio and Kmp (growth rate calculated by radius of mycellium, cm/day) of P. sajor-caju and P. flavellatus were shown as 122%, 0.690 cm/day and 110%, 0.647 cm/day at 1% of NRSP concentration compared with those of C. phlytidosprorus which were shown as 124% and 0.709 cm/day at 0.2% of NRSP concentration. Liquid and solid state fermentation were performed to investigate the effects of NRSP addition on each media. NRSP was added as 0, 0.1, 1 and 5% in all fermentation media. Liquid state fermentation was performed using three kinds of liquid medium. In the complete Mandel``s medium with 1% glucose which only considers the NRSP effect, the protein concentrations of P. sajor-caju, C. phlytidosprorus and V. volvacea were increased in 2.1, 2.95, and 2.44 times at 5% of NRSP compared to those with no NRSP added. To investigate the NRSP effect on the cellulosic waste, the complete Mandel``s medium with 1% sugar cane bagasse(w/v)...