Diversity Analysis Of Culturable Bacteria Of The South Atlantic And Classification And Identification Of Novel Species

Deep sea has high salt, high pressure, extreme acid, extreme alkaline, extreme cold, oligotrophic, low light or no light characteristics. Deep-sea bacteria have special physiological characteristics, environment functions and great potential in application. In this study, the bacteria were isolated and identified from59samples of deep-sea sediment, sea water, fly fish, hatchetfish and coral etc, which are sampled from the south Atlantic. We obtained581strains of bacteria in total, by direct isolation and isolating after enrichment with hydrocarbons and heavy metals, and349strains were isolated by teacher shao. They were identified through the following steps of extraction of genomic DNA, PCR amplification16S rRNA gene and sequence anslysis. These bacteria belonged to90genera of6classes. Alphaproteobacteria and Gammaproteobacteria occupied40%and29%of the total, respectivly. At genus level, the top ten genera and their abundance were Marinobacter (13%), Alcanivorax (9%), Erythrobacter (7%), Halomonas (6%), Sulfitobacter (5%), Pseudoalteromonas (5%), Alteromonas (3%), Oceanicola (3%), Pseudomonas (3%) and Idiomarina (2%).Among these strains,29potential novel species were expected, which shared16S rRNA gene sequence similaritied less than98%with any previously described type strains. In this study,5strains representative of5potential novel species were further characterized with strandard procedure of bacterial taxanomy, including16S rRNA gene sequences and phylogenetic tree analysis, physiological and biochemical analysis, fatty acids composition analysis and molecular biological analysis etc. As a result,strain22â…¡-S10r2of class Gammaproteobacteria is identified as a novel genus, named Maricoccus atlantica. Strain22â…¡-S10s of genus Roseivivax is identified as a novel specie and named Roseivivax atlanticus. Strain2211-S11g of genus Oceanicola is identified as a novel specie and named Oceanicola atlantica, and it is the seventh discovered strain of this genus. Strain22â…¡-S11-z10of genus Actibacterium is identified as a novel specie and named Actibacterium atlantica. Strain22â…¡-S11-z7of genus Aquimarina is identified as a novel specie and named Aquimarina atlantica. In short, results of this study provided lots of new microbial strains for further investigation of deep-sea microbiology. Among these strains,32strains are potential heavy mental resistant strains of copper, cadmium and chromium.77strains are potential oil degradation strains, which belong to32genus and40species. The top five genera are Alcanivorax, Martelella, Oceanicola, Sulfitobacter and Muricauda.This study not only obtained lots of bacteria strains, but also systematically classified and identified5novel bacteria species, which provided important information for understanding the diversity of culturable microorganism of the south Atlantic.