Production of single cell protein from hydrolyzed pineapple (Ananas comosus) peel using fungi

Production of single cell protein from hydrolyzed pineapple peels 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 (138 mg/ml, 298 and 9.44 mg/ml) have higher reducing sugar, soluble sugar and protein content than H2SO4 (129, 206l and 6.28 mg/ml) and HCl hydrolysates (131, 279 and 7.32 mg/ml), respectively. The culture of Trichoderma viride were used in fermenting the hydrolyzed pineapple peels. The protein yield in 0.5% NaOH hydrolysates (27.35 mg/ml) was significantly (p ≤ 0.05) higher than H2SO4 hydrolysate (18.32 mg/ml) and HCl hydrolysate (16.48 mg/ml) after 7 days incubation. The un-hydrolyzed samples which served as control produced the lowest protein. Nitrogen sources were added to the media supplemented with ammonium oxalate [(NH4)2C2O4], which gave the highest protein 55.44 mg/ml for NaOH hydrolysate. The maximum weight of biomass after drying biomass was 0.66 g/100ml. This study demonstrated the potential of pineapple peel as a substrate for product recovery, waste control and management.

 P.N. Clement, O Nwokoro