Isolation And Diversity Analysis Of Deep-sea Bacteria In South Atlantic

Deep sea, with very different character from land, the biological resources arevery rich. And the number of microorganism is the largest in the deep sea. Manyresearchings are focusing on microorganism resources and the active substances thatproduced by them, especially some kinds of enzymes. Some of those activesubstances are more tolerance and resistance. Studying the marine microbialdiversity can make us to have more comprehensive, stereoscopic, profoundknowledge about the marine environment. The knowledge not only provide us animportant reference utilize marine microbial resources, but also more valuable cluesto study the origin of life and evolution.In this researching different culture mediums and methods were used to isolatebacteria from sediment samples and seawater samples taken from South Atlantic.16S rDNA sequence analysis was utilized to identify these isolates and study theirdiversity. Some isolates were selected to study the ability of anti the growth ofAspergillus parasiticus and producing of aflatoxin.265strains were isolated from the seawater samples by using2culturemediums.237strains’ identify results were gotten with16S rDNA sequence analysis.Results showed that those isolates were belonged to47genuses, and most of themwere Erythrobacter, Alteromonas and Marinobacter;17strains with less than97%similarity value with sample strain selected from gene back, had potential to be newspecies.848strains were isolated from the sediment samples.474strains’ identifyresults were gotten with16S rDNA sequence analysis. Results showed that thoseisolates were belonged to23genuses, and most of them were Marinobacter andHalomonas, belonging to the γ-Proteobacteria group.195isolates were selected for further studying about the ability of anti thegrowth of Aspergillus parasiticus and producing of aflatoxin by using freshwater gYand seawater gY medium. Results indicated that their growth type and nutrientutilization and adaptation to the environment were diverse, but most of the bacteriawere more adapted to seawater medium.There are33strains of Aspergillusparasiticus mutant NFRI-95showed varying degrees of inhibition rate. Most of thestrains showed higher inhibition rate.