MICROBIAL DIVERSITY ASSOCIATED WITH THE BRAZILIAM ENDEMIC REEF CORAL MUSSISMILIA HISPIDA

Alinne Castro (UnB); Samuel Araujo (UCB); Alessandra Reis (UCB); Rodrigo Moura (CI-Brasil); Ronaldo Filho (UEPB); Georgios Pappas (UCB); Bruno Silva (UFRJ); Fabiano Thompson (UFRJ); Ricardo Kruger (UnB)

The Abrolhos Bank is one of the most important reef biomes of the planet and is located at the eastern Brazilian coast. The coral reefs spanning in this area play a crucial ecological role in the health of the whole South Atlantic Ocean, by providing nursery place for a variety of marine life. The reef coral species Mussismilia hispida play a key role in marine life and also sustains an important fishing activity that represents the main source of food and employment for thousands of people. This organism, endemic of Brazil, is one of the main reef builders, yet it has been under serious threat in the last years. The actual aetiological and/or causal agents of massive extinction of M. hispida are not fully known, but microorganisms might well be important players in the health of this coral. The aim of this study is to analyze the microbial diversity associated with health and diseased M. hispida colonies in a key area of the Abrolhos Bank, the Itacolomis reef. Both the sea water surrounding the colonies and coral mucus samples were taken in different locations within this reef. Samples were filtered through 0,2 mm membranes and the DNA was extracted from the retained bacterial cells. Due to small DNA quantity and the presence of high levels of polyphenolic compounds and sugars in the coral mucus samples, different DNA extraction methods were tested and adapted in order to yield enough quality DNA amounts. Four 16S rRNA libraries comprising about 1600 clones were sequenced. Preliminary phylogenetic analyzes of the inserts revealed the presence of potential coral pathogens and several new taxa. However, the main groups were Proteobacteria, Bacteroidetes, Cyanobacteria and unclassified bacteria according to the 16S rRNA libraries. Actually, this study is a first survey of the M. hispida microbiota diversity.