Microbiological and physico-chemical characteristic of Rwandese traditional beer "Ikigage"

Samples of traditional sorghum beer Ikigage was collected in the southern province of Rwanda and analyzed for microbiological and physico-chemical contents. Ikigage contained total aerobic mesophilic bacteria (33.55 x 10 super(6) cfu/ml), yeast (10.15 x 10 super(6) cfu/ml), lactic acid bacteria (35.35 x 10 super(4) cfu/ml), moulds (4.12 x 10 super(4) cfu/ml), E. coli (21.90 x 10 super(3) cfu/ml), fecal streptococci (22.50 x 10 super(3) cfu/ml), Staphylococcus aureus (16.02 x 10 super(3) cfu/ml), total coliform (32.30 x 10 super(3) cfu/ml), ethanol, soluble protein, reducing sugars, total acidity, pH and Brixwere 2.2% (v/v), 9.2 g/l, 2.3, 1.7%, 3.9 and 11.5 bx, respectively. The yeast was identified by API 20 C test and confirmed by PCR-Sequencing of ITS-5.8S region of rDNA. Seventy yeasts isolated in the samples were found to belong to either Saccharomyces cerevisae, Candida inconspicua, Issatchenkia orientalis, Candida magnolia and Candida humilis. Lactic acid bacteria were identified using the API 50 CHL system. Ten different isolates of lactic acid bacteria belonged exclusively to the genus Lactobacillus: Lactobacillus fermentum, Lactobacillus buchneh, and Lactobacillus sp. The micro-organisms of fecal origin are from the water and the operations post-fermentation process. The presence of potential pathogens emphasizes the importance of developing starter cultures with GRAS status for commercialization of ikigage.