THE BACTERIAL COMMUNITIES ASSOCIATED WITH TWO MARINE SPONGES OF THE GENUS XESTOSPONGIA

Abstract

Marine sponges are sessile, filter-feeding, multicellular invertebrates that host diverse assemblages of microbial organisms, including bacteria, diatoms, and fungi. Marine sponges and their microbial associations are important in the field of drug discovery, and are models for studying the complex symbioses that exist between eukaryotes and bacteria. The bacterial communities associated with Xestospongia muta from the Florida Keys and Xestospongia testudinaria from Indonesia were being compared to reveal key symbionts that are important to these sponges. These two sponge species have been separated for millions of years and some groups of bacteria will have been maintained for this time because they have important roles as symbionts. We hypothesize that the bacterial communities associated with giant barrel sponges of the genus Xestospongia have a characteristic composition that includes novel species. Based on these observations, the experimental focus of this proposal is on in-depth analysis of the bacterial communities associated with Xestospongia spp. sponges. Both molecular and culture-based techniques are used to characterize and compare the bacterial symbionts of X. muta and X. testudinaria.