Isolation and identification of Bioflocculant producing bacteria from soil samples of Tay Nguyen, Vietnam

This paper described isolation and identification of the bioflocculant producing bacteria from soil samples of Tay Nguyen region, Vietnam. A total of 117 bacteria were isolated, among of which 26 isolates showed flocculating activity more than 50%. In addition, the influence of carbon and nitrogen sources, as well as cultural conditions such as temperature, pH and incubation time on flocculating activity of the 3 selected flocculant producing isolates were investigated. Obtained results revealed that that selected isolates preferred organic nitrogen source and different carbon source for maximum flocculating activity. The suitable culture temperature and pH for their activity ranged from 300C-350C and from light acidity to light alkalinity, respectively. The incubation time for highest flocculating activity of the isolates varied from 48 h (Bx-vk22) to 72 h (Bx-f9 and Bx-vk9). The selected isolates were identified based on 16S rRNA gene sequence and the obtained results showed that the isolates Bx-f9, Bx-vk22 and Bx-vk9 belonged to three different genera, including Bacillus, Lysinibacillus, and Enterobacter respectively.