Production of single cell protein from hydrolyzed pineapple (<i>Ananas comosus</i>) peel using fungi

Abstract

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, H 2 SO 4 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 H 2 SO 4 (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 H 2 SO 4 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 [(NH 4 ) 2 C 2 O 4 ], 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. Keywords: Single cell protein, Ananas comosus , Cellulose, Pineapple, Fungi