Comparative Study on Microbial Loads of Fermented Castor Oil Seeds (Ricinus communis) and Melon Seeds (Citrullus vulgaris)

Various types of microorganisms were isolated from fermented products of castor oil seeds and egusi. The fermented products are mainly used as condiment soup among populations in Nigeria. The total bacteria load in fermented castor oil seed and egusi was in average of 195.0 � 9.6 x 107 cfu/g and 145.7 � 12.5 x 107 cfu/g respectively, while the total viable count of fungi cells show that castor oil seed ogiri contained 3.3 � 1.5 x 102 cfu/g and 2.7 � 0.6 x 102 cfu/g for egusi seed ogiri. The bacterial and fungi loads of ogiri made from castor oil seeds are more than ogiri from egusi. The bacteria flora species obtained include Lactobacillus, Bacillus, Enterobacter, Streptococcus, Pseudomonas and Escherichia. Fungi flora include Rhizopus, Penicillin, Aspergillus and Yeast species. They were characterized based on microscopy, colony features, biochemical reactions and sugar utilization. The result from this study confirmed that different microorganisms are associated in fermentation of castor oil seeds and egusi in the production of ogiri.