Diversity And Enzyme Activities Of Culturable Bacteria From The Tengchong Hot Spring

Study on microbes in the extreme environments in recent years has become a hotspot. Researchers have found many new species and new functional genes from these specific conditions. In this study, we isolated cultural bacteria from Tengchong hot spring and analyzed amzyme activities of bacteria. The results are as follows:1. Using 7 different selective media, we isolated 3053 strains of bacteria from 18 hot spring samples. Phylogenetic analysis infered 16 S r RNA sequences showed from these strains were grouped into 86 morphological types and 8 described genera, including Bacillus, Pseudomonas, Pantoea, Anoxybacillus, Paenibacillus, Oceanobacillus, Escherichia, and Enterococcus.2. Enzyme activity analysis showed that 38 strains produced cellulase, 50 strains produced amylase, 33 strains produced laccase and 5 strains produced lipase. In addition, 29 strains could produce one single enzyme, 28 strains had two kinds of enzyme activities, and 13 strains produced three kinds of enzyme activities. Enzyme production showed that the strain of Bacillus sp. Dgg2, Pseudomonas sp. F2, and Pantoea sp. ZMQR4 had a better cellulase production capability.3. By the single-factor experimental method, the optimal carbon source for the Bacillus sp. Dgg2, Pseudomonas sp. F2, and Pantoea sp. ZMQR4 to produce cellulase was CMC-Na, CMC-Na, and wheat bran, the optimal nitrogen source was soybean flour, beef paste, and beef paste, the optimum temperature was 55°C, 60°C, and 60°C, the optimal initial p H was 6.5, 5.5, and 7.0, and the optimal inoculum size was 7.5%, 5.0%, and 2.5%. Orthogonal tests showed that the optimal conditions for Bacillus sp. Dgg2 to produce cellulose enzymes were as follows: the culture temperature was 52°C, the initial p H 6.2, the inoculum size 7.0%; the optimal medium composition contained CMC-Na(15 g/L), soybean flour(8 g/L), Peptone(2 g/L), yeast extract(0.5 g/L), Ca Cl2(0.3 g/L), K2HPO4(2.0 g/L), and Mg SO4·7H2O(0.5 g/L).This study obtained cultural bacteria from Tengchong hot spring in Yunnan, and investgated enzyme activities of these strains, providing significant microbial resources for further utilization.