Comparison of Bacterial Population Structure in High and Low Somatic Cell Bovine Milk in Patthalung Province

Abstract

This study is aimed to compare the bacterial population structure of two different raw milk sample groups, low somatic cell (LSC) and high somatic cell (HSC) samples, using culture-dependent and culture-independent methods. The somatic cell count was estimated by California Mastitis Test (CMT) and Fossomatic 5000. Based on difference of V3 sequences of 16S rRNA gene using Denaturing Gradient Gel Electrophoresis (DGGE), bacterial diversity was identified. The bovine raw milk samples were collected from dairy farm of Thaksin University, Pha-prayom district, Patthalung province. The total bacterial counts in both samples were grown on Plate Count Agar (PCA) that showed no significant difference (p≤0.05) between HSC and LSC which were 4.75±0.9, 4.29±0.87 and 3.81±1.32 Log CFU/ml of CMT0, CMT+2 and CMT+3, respectively. There are four bacterial phyla from culture-dependent methods including Firmicutes Proteobacteria Actinobacteria and Bacteroidetes. This method showed that the genera of Staphylococcus and Bacillus were dominant bacteria and Corynebacterium spp. were frequency detected from HSC samples higher than LSC samples. Moreover, Sphingobacterium spp. were presented in HSC but not in LSC. While culture-dependent methods showed three phyla including Firmicutes Proteobacteria Actinobacteria as well as uncultured bacteria. Streptococcus spp. Lactobacillus spp. and Bacillus spp. were detected as dominant bacteria.