Molecular Identification of Black Band Disease on Pachyseris sp in Spermonde Archipelago

The researchers isolated five bacteria from healthy coral tissue infected with BBD and four bacteria from coral tissue associated with BBD. The isolated bacteria were identified using the nitrogen base sequence analysis method on the 16S rDNA nucleotide constituents. The researchers extracted DNA from the isolated bacteria and amplified the 16S rDNA genes using Polymerase Chain Reaction (PCR). The amplified fragments were then analyzed for homology with the 16S rDNA gene sequences of other bacteria in the GenBank database. The results showed that the isolated bacteria had similarities with various species, including Halomonas sp, Pseudoalteromonas sp, Thiobacillus denitrificans, Psychromonas ingrahamii, Shewanella sp, Bacillus farraqinis, Flavobacterium, and Desulfovibrio salexigen. The study found that the Black Band Disease is a kind of disease that infects coral reef networks, attacking malignant and spreading globally at various coral species. The disease is believed to be caused by a microbial consortium, but the cause of the disease agent has not been definitively identified. The researchers used the 16S rDNA gene sequence analysis method to identify the pathogenic bacteria causing BBD, which is considered a more accurate method than phenotypic analysis. The study was conducted in the waters of Barrang Lompo, Badi, Bonetambung, Sarappo, Kapoposang, and the Spermonde islands, South Sulawesi, from July 2013 to March 2014. The researchers collected coral samples from infected and healthy coral, and isolated bacteria from the infected coral tissue. The isolated bacteria were then grown in culture and DNA extraction was performed for further analysis. The PCR amplification of the 16S rDNA genes was carried out using universal primers for the domain bacteria. The PCR products were analyzed through agarose gel electrophoresis, and the results showed that the amplified fragments had the expected size of 50-1000 bp. The study highlights the importance of identifying the pathogenic bacteria causing BBD, which can be used as information for the control of coral health problems. The researchers used the Boom's method for DNA extraction, which involves centrifugation and repeated washing steps to obtain high-quality DNA. The quantity and purity of the extracted DNA were measured using a Biophotometer plus. The study demonstrates the effectiveness of the 16S rDNA gene sequence analysis method in identifying the pathogenic bacteria causing BBD, and highlights the need for further research on coral diseases in Indonesia. The study was conducted in collaboration with the Leibniz-Zentrum für Marine Tropical Ekologie (ZMT) Bremen, Germany, and the Faculty of Medicine and Molecular Identification. The researchers used a combination of molecular and microbiological techniques to identify the pathogenic bacteria causing BBD, and the study provides valuable information for the control of coral health problems in the Spermonde Archipelago.