Of Qinglangang Mangrove Microbial Flora And Soil Bacterial 16s Rdna Polymorphism Study

Nineteen mangrove soil samples were collected at Qinglan harbor in Hainan province. Colonies of bacteria, actinomycetes and fungi were numbered by culture-dependent approaches. The soil water contents, salinities, pH, and N, P, K contents were determined and their effects on the colony numbers of bacteria, actinomycetes and fungi were analyzed. All bacteria and actinomycetes strains with different colony-configuration were isolated from each soil sample and their bio-activity against tumor cell, Candida abbicans and Staphylococcus aureus were detected respectively, which may accordingly provide some referable data to exploiting the microbial resource in mangrove soil. The 16S rDNA diversity of bacteria was studied by directly extracting bacteria DNA from mangrove soil and employing polymerase chain reaction, denaturing grade gel electrophoresis (DGGE) and clone technology. Two DNA slices were separated from one sample in denaturing grade gel, where the DNA were recovered and used to establish two clone libraries, named A clone libraries and B clone libraries. Thirteen clones were randomly selected from A clone libraries and sequenced. The clone A-l sequence was sequenced three times. Among 22 most-similar sequences in GenBank responded to 11 different sequences of clone A, uncultured bacteria sequences presented 77%. Ten clones were randomly selected from B clone libraries and sequenced. Among 20 most-similar sequences in GenBank responded to 10 different sequences of clone B, uncultured bacteria sequences presented 85%. From the phylogenetic tree established mainly to A clone libraries, we found that 4clone A sequences were closely related to sulfate-reducing bacterium (AJ012598). Their sequence similar rates were 79-88%.