Isolation and identification of bacterial communities from coral tissue affected by black band disease at pulau redang, terengganu, malaysia

Coral reefs in Southeast Asia are becoming progressively degraded due to the natural and anthropogenic disturbances which lead to poor water quality threatening the reefs' health. Coral disease is one of the threats to the coral reefs worldwide but research on coral disease in Southeast Asia is relatively scarce especially on bacterial community associated with the disease. The destructive coral black band disease (BBD) can be found widely in the southern region of the South China Sea, Malaysia. This study aims to compare the microbial communities of healthy and BBD-infected coral tissue from two different coral species Montipora turtlensis and Acropora spicifera collected at the Shark Point of Pulau Redang, Terengganu. The bacterial isolated from corals nubbins were examined by combining culture-dependent method and bacterial sequencing of 16S rDNA. A total of 18 bacteria isolates were identified from both species of coral tissue samples prior to sub-culturing colonies samples. The sequences detected were derived from a wide taxonomic range, including representatives of Actinobacteria, Furmicutes and Proteobacteria phyla. Bacteria belonging to the phyla Proteobacteria were further divided into alpha and gammaproteobacteria. Most of the bacteria identified can be found on healthy and BBD-affected coral tissue samples; however, there are few bacteria which can be only found on BBD-affected tissue of respective coral species such as Lelliottia sp., Salnicola salarius and Microbacterium petrolearium for M. turtlensis while Pseudomonas stutzeri and Erythrobacter sp. for A. spicifera.