Diversity of bacterial flora of Indonesian ragi tape and their dynamics during the tape fermentation as determined by PCR-DGGE

The diversity of bacterial flora of ragi tape, an Indonesian traditional dry starter, was analyzed using culture independent methods, the Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCRDGGE). The result revealed the lactic acid bacteria were the predominant bacterial flora of ragi tape. Weissella spp., Pediococcus pentosaceus, Lactobacillus spp. and Enterococcus spp., were detected in all 9 ragi tape samples, Bacillus cereus detected in 3 out of 9 samples, swine manure bacterial species related to Clostridium perfringent was detected in 3 out of 9 samples. Remaining uncultured bacteria of either Eubacterium moniliforme, Clostridium sardiniensis, or Clostridium baratii was detected in one out of 9 samples. Pediococcus, Weissella and Enterococcus consistently developed during the tape fermentation; while the Lactobcillus sp. started to grow after 24 h fermentation then its population likely decrease afterwards. The active growth of LAB during the tape fermentation implies that these bacteria might play significant contribution on the flavor of tape and brem.