Solid State Fermentation of Plant Protein Meals Using Lactobacillus acidophilus for Improving Feed Value

Abstract

Usage of some legumes and oil seed meal as fishmeal substitute is hampered by low protein content and anti nutritional factors (ANF). Inclusion of some exogenous enzyme cocktail like phytase, xylanase can reduce some ANF but is costly. Solid state fermentation of plant proteins is affordable and could be useful in upgrading the protein content, elevating the nutrient and mineral status and eliminating ANF from plant-based feed ingredients. We therefore extracted Lactobacillus acidophilus from intestine of adult African catfish. Extracted L. acidophilus was cultured at 37°C for 48 hrs in Mueller-Hinton Broth. Approximately 10 g of the bacteria broth containing 9.4 log 10 colony forming unit (CFU) per ml was mixed with 200 g meals of bambaranut meal and African yam beans meal placed in a brown bottom flask. The ground meals and bacteria mixtures were fermented for 72 hours. Temperature was maintained at 28.6°C to 34°C. The pH of the mixtures was measured everyday and the fermenting mixture was regularly stirred. Fermentation was stopped after 72 hrs and the meals were subjected to proximate analysis. Protein content of the meals significantly increased (P<0.05) as follows: BNM, 24.82±0.15% to 40.37±0.27% and AYB, 23.65±0.07% to 34.56±1.36%. Lipid content of meals significantly increased (P<0.05) as follows BNM, 7.11±0.01 to 14.29±0.05% and AYB, 2.96±0.45% to 5.76±0.09%. There was general decrease in composition of carbohydrate and ANFs were drastically reduced or completely eliminated from the meals.