Dadih is a naturally fermented milk product developed traditionally by local people in West Sumatra, Indonesia. This product is produced using unpasteurized buffalo milk that is fermented spontaneously at an ambient temperature for 2 – 3 days. In this study, dadih samples were collected periodically during the three days fermentation period. After extracting the bacterial DNA, the strains were characterized using PCR ITS-RFLP followed by identification using 16s rRNA sequencing. The multiplex barcoded pyrosequencing of a hypervariable V1−V3 region of the 16S rRNA gene tagged with sample-specific barcodes for multiplex identifiers was employed for bacterial community profiling. Three predominant groups of bacteria were detected in all fermentation periods using these methods; namely lactic acid bacteria (Lactococcus lactis subsp. lactis), Enterobacteriaceae (Klebsiella oxytoca) and acetic acid bacteria (Acetobacter orientalis). The abundance of Lac. lactis subsp. lactis increased rapidly from the early stages of fermentation and was accompanied by a decrease of pH values. On the other hand, the growth of K. oxytoca decreased probably in response to the acid conditions. A gradual increase in numbers of A. orientalis was also observed within two days of fermentation, however, the abundance was lower than for Lac. lactis subsp. lactis. The other lactic acid bacteria also detected were Lactobacillus plantarum and Enterococcus faecium. This bacterial community analysis indicates that the role of lactic acid bacteria is important not only in developing the product’s qualities but also improved the product’s safety.
Keywords: buffalo milk, dadih, fermented milk, pyrosequencing, PCR ITS-RFLP