The Occurrence of Bacillus cereus in the Pink Line Syndrome Infected Porites lutea Coral

Corals in the genus Porites are among the most dominant scleractinian corals in the coral reef ecosystems yet highly vulnerable to climate change impacts and diseases. In the Kondang Merak and Sempu Strait waters of Indian Ocean, it has been reported that more than 45% of the corals were infected with Pink Line Syndrome (PLS). The objectives of this study are to isolate, morphologically and molecularly characterize, and identify the PLS associated bacteria that infected Porites lutea coral. The sampling was performed at the Kondang Merak waters in June 2018 by snorkeling during low tide. In order to isolate and purify the dominant bacterial colony, quadrants streak-plating technique was performed using ZoBell marine agar culture media. 16S rRNA sequencing and BLAST homology were performed for the molecular identification of the bacterial colony. Results showed that the bacterial colony associated with PLS was of Bacillus cereus, which was closely related to Bacillus pseudomycoides, Bacillus toyonensis and Bacillus thuringensis with 97% similarity. The occurrence of B. cereus bacterium in the PLS infected P. lutea demonstrated that this opportunistic pathogen might be responsible for the PLS in the P. lutea coral.