Bioconversion of rice bran with Arachniotus spp. and Candida utilis to protein biomass and its evaluation

Rice bran was subjected to proximate analysis to know its nutritive potential. Arachniotus spp and Candida utilis were used as fermentating agents to carry out solid state fermentation of 5 g rice bran after determining the optimum conditions such as incubation period (3 days), water: substrate (1:2 w/v), ionic concentrations. (MgSO4, 7H2O, 0.05%; CaCl2, 0.075%, KH2PO4, 0.250%) carbon to nitrogen ratio (12:1), molasses (1 ml), yeast sludge (0.6 ml) and corn steep liquor (2.0 ml) for Arachniotus spp. while for Candida utilis molasses (2 ml) and urea (0.25 g) for maximum production of biomass protein. The biomass (fungal and yeast) protein produced under these conditions on large scale in Koji fermenter. It contains crude protein, 30.13%, true protein, 23.74%; ash, 14.71% and RNA content 3.383%. It was observed that on large-scale biomass production, there was more need of optimization of conditions like agitation, pH and supply of oxygen. The fermented biomass protein was also analyzed for amino acid profile. To evaluate biologically the quality of protein of the biomass a feeding trial was conducted using day old broiler chicks. These chicks were fed rations in which 5% (B), 10 % (C), 15% (D), and 20% (E) Soya bean were replaced with biomass protein from a basal diet (A) for 42 days. The quality of biomass protein was evaluated in terms of feed conversion ratio, weight gain, feed consumption and protein efficiency ratio. It was observed that the difference between the values of feed conversion ratio, and Protein efficiency ratio total weight gain and total feed consumption were statistically significant. It was that group A had better FCR of 2.24, group C had more feed consumption 4131 g / chick, group C had more weight gain which was 1764.5 g / chick while group A had better PER which was 2.30.