Denaturing Gradient Gel Electrophoresis Analysis of Microbial Community Variation in Bleached and Non-bleached Montastraea faveolata

Abstract

Previous studies have shown that coral maintain a symbiotic relationship between themselves, algal zooxanthellae, and bacteria. Although the role of bacteria in coral health is not fully understood, it is believed that some bacteria fix nitrogen for the zooxanthellae (Lema 2012), making the health of the microbial community very important to the overall health of the coral. As ocean temperatures continue to rise, bleaching has come to be a major cause of coral mortality. This study utilizes denaturing gradient gel electrophoresis (DGGE) to analyze the microbial communities of Montastraea faveolata under normal and bleached condition to determine what effects bleaching has on these microbial communities. After fragments were collected from nine parent colonies taken from three locations, half were exposed to heat stress in order to induce bleaching before analysis. Although much of the microbial community was conserved between samples, differences were found between fragments taken from different locations and those exposed to different treatments. In addition, a divergence was found between bleached fragments with similar beginning compositions which has not been found in previous studies.