The Use of Fungi in the Production of Single Cell Protein from Hydrolyzed Pineapple (Ananas Comosus) Peel Wastes

Abstract

The growing shortage of protein rich food supplies has stimulated the effort in searching alternate source of protein rich foods. Therefore, sources mainly microorganisms named single cell protein (SCP) was coined to describe the protein produced from microbial biomass. Single cell protein production on hydrolyzed pineapple peel waste by fungi was investigated. Trichoderma viride was selected based on its high cellulase activity; diameter of clear zone on CMCagar (7.4 cm) and activity on carboxymethylcellulose (4.64 mg glucose/ml), filter paper (3.76 mg glucose/ml) and cotton wool (4.12 mg glucose/ml). Samples of pineapple peel were hydrolyzed with the solutions of HCl, H2SO4 and NaOH at 0.5% concentration.The NaOH hydrolysates (138mg/ml, 298mg/ml and 9.44mg/ml) contained higher reducing sugar, soluble sugar and protein content than H2SO4 (129mg/ml, 206mg/ml and 6.28mg/ml) and HCl hydrolysates (131mg/ml, 279mg/ml and 7.32mg/ml) respectively. The culture of Trichoderma viride was used in fermentation of hydrolyzed pineapple peels. The protein yield produced in 0.5% NaOH hydrolysates (27.35 mg/ml) was significantly (p ≤ 0.05) higher than that of H2SO4 hydrolysate (18.32 mg/ml) and HCl hydrolysate (16.48 mg/ml) after 7 days of incubation. The unhydrolyzed samples which served as control produced the lowest protein. Several nitrogen sources were added to the samples, the media supplemented with ammonium oxalate [(NH4)2C2O4] gave the highest protein of 55.44 mg/ml for NaOH hydrolysate. Different concentrations (2%, 4%, 6%, 8% and 10%) of glucose were also added to the extracts and the protein yield increased. At day 7, the protein content of NaOH hydrolysate with 10% glucose (42.95 mg/ml) was the highest. The maximum weight of biomass produced after drying of biomass was 0.66g/100ml. This study demonstrated the potential of pineapple peel waste as a substrate for by- product recovery and waste management.