Production of Standard “Kissra” Starter Culture

Abstract

Kissra is traditionally prepared by fermenting sorghum grain flour and then baked it into bread sheets. In this study a total of 75 lactic acid bacteria (LAB) and 19 of yeast isolates have been recovered from fermented kissra dough and characterized at species strain level with molecular tools. RAPD analysis was performed initially to cluster the isolates using two different primers R2 and M13. Species identification was based on sequence analysis of 16S rRNA gene. Nine clusters of LAB PCR products sequenced and subjected to nucleotide BLAST. Three isolates (4%), (group1L) showed 100% homology towards Pediococcus acidilactic , and five isolates (6.7%), (group 9L) showed 100% homology towards Lactococcus lactis subsp. lactis strain SFL. Among the rest of the 67 lactobacillus isolates, one isolate (1.6%), (group 2L) showed 100% homology towards L. murinus , also same percentage 1.6% (group 4L) reported as L. casei strain IMAU70007, two isolates (2.9%), (group 5L) showed 100 homology towards L. plantarum strain KLAB4. The same percentage 2.9% (group 8L) were showed similarity 100% towards L.fermentum. Four isolates (5.9%), (group 7L) showed 100 homolog towards L.casei strain SWU30436, 20.9% (14 isolates), (group 3L) were showed similarity 100% towards L. plantarum strain 1.0557CGMCC, while the majority of the isolates 64.2% (43 isolates), (group 6L) showed 100 homology towards L. plantarum strain CSI7. Phylogenetic analysis was performed using software MEGA 6.0. For yeast The 18S-28S ITS region was amplified using the fluorescence labelled CY5-Y-ITS1 forward primer and YITS4 reverse primer. By the ITS-PCR profiles, the isolates were divided into two groups of yeasts. The blast sequence query showed that members of groups 1Y and 3Y identity (100%) with the genomic DNA sequence of Saccharomyces cerevisiae, while group 1C and 5C identity (100%) with the genomic DNA sequence of Candida xylopsoci. Proximate values of kissra from standard culture were compared with those of kissra brought from the market. There were variable values in protein, fat, oil, moisture, ash, carbohydrate and fibre contents of different types of kissra. All minerals were significantly different (P <0.05) and invitro protein digestibility was found higher in the control. On the other hand, tannins and polyphenols were found low in the control compared to all other types of kissra. For phytic acid, two types of standard kissra and the control showed no significant difference. Sensory evaluation showed that the kissra which made from standard culture, had the higher score in all quality attributes compared with kissra from market.