Isolation, Characterization and Identification of Lactic Acid Bacteria from Fermented Sorghum Dough Used in Sudanese Kisra Preparation

Abstract

Forty two isolates were selected from 15 samples of traditionally fermented household starter dough from Khartoum state and also from laboratory-prepared fermented dough. Isolates were phenotypically characterized by their ability to ferment 21 carbohydrates using API 20 CHL kits and additional biochemical tests. Lactic Acid Bacteria (LAB) and yeasts were enumerated. The pH and lactic acid content were also determined. The LAB counts in household fermented dough varied between 7.1 and 9.4 log cfu ml and yeast counts between 4.3 and 7.7 log cfu ml. The pH of household starter ranged from 3.7-4.5. The -1 initial numbers of LAB in laboratory-fermented sorghum dough were increased from 5.5-9.0 log cfu ml during fermentation. Yeasts increased from 4.3-7.7 log cfu ml at 19 h. The pH declined from 5.04 to around 3.7. Lactic acid increased from 0.03-1.25%. Lactic acid bacteria isolated from both traditionally and laboratory prepared fermented dough were Lactobacillus fermentum, Lactobacillus amylovorus and Lactobacillus brevis. The yeast isolates were identified as Saccharomyces cerevisiae.