Fermentation and protein enrichment of Cassava pulp and rice husks using rumen digesta and their evaluation as diets for Swiss rats

Abstract

The protein content of pulped cassava and rice husks were enhanced by fermentation using native populations in Rumen digesta as source of inoculum. After three days of fermentation the microbial population increased with microbial succession as the fermentation progressed. A mixed culture of yeast and bacteria were isolated and identified from the fermenting liquor of cassava pulp, Rumen digesta and rice husk namely: Clostridium perfrigenes, Lactobacillus plantarum, Enterococcus faecium, Streptococcus lactis, Enterococcus faecalis. Fungi types include Geotricum candidum, Candida tropicalis, and protozoa were Entamoeba histolytica. The crude protein value also increased with the increasing microbial population from an initial value of 5.6% to 18.2%. Decrease in pH from 7 to 3.5 enhances growth of lactic acid bacteria. The dewatered and dried slurry obtained after fermentation was used to formulate murine diets. No mortalities were recorded on experimental feeding of rats on the new diet formulation. The new rations compared favourably in percentage digestibility with a commercial murine feed. The results form a base for further work on the use of rumen digesta for monogastric animal feed production.


Key Words: Fermentation, Protein Enrichment, Rumen Digesta, Cassava, and Rice Husks


Journal of Tropical Microbiology Vol.3 2004: 71-77