Send Orders for Reprints to reprints@benthamscience.net Current Pharmaceutical Biotechnology, 2014, 15, 143-155 143 Biotechnological Potential of Sponge-Associated Bacteria Juliana F. Santos-Gandelman, Marcia Giambiagi-deMarval, Walter M.R. Oelemann and Marinella S. Laport * Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, Cidade Universitária, 21941-590, Rio de Janeiro, Brazil Abstract: As sessile and filter-feeding metazoans, marine sponges represent an ecologically important and highly diverse component of marine benthic communities throughout the world. It has been suggested that marine sponges are hosts to many microorganisms which can constitute up to 40-60% of its biomass. Recently, sponges have attracted a high interest from scientific community because two important factors. First there is the fact that sponges have a wide range of associated bacteria; and, second, they are a rich source of bioactive substances. Since 1950, a number of bioactive sub- stances with various pharmacological functions have been isolated from marine sponges. However, many of these sub- stances were subsequently shown to be actually synthesized by sponge-associated bacteria. Bacteria associated with ma- rine sponges constitute an interesting source of novel bioactive compounds with biotechnological potential such as antim- icrobial substances, enzymes and surfactants. In addition, these bacteria may be biofilm forming and can act as bioindica- tors in bioremediation processes of environmental pollution caused by oil and heavy metals. This review focuses on the biotechnological applications of these microorganisms. Keywords: Bioactive substances, bioindicators, biofilm, bioremediation, biosurfactant, sponge-associated bacteria. INTRODUCTION As the simplest and most primitive metazoans, marine sponges are important components of benthic communities due to their biomass and potential influences on pelagic processes [1-4]. Marine sponges belong to the phylum Porif- era which consists of four classes, Hexactinellida, Calcarea, Demospongiae, and Homoscleromorpha, the latter of which was more recently established [5]. The architecture of sponges differs from that of any other taxon. Sponges are the simplest form of multi-cellular ani- mals. They do not possess typical tissues found in other mul- ticellular animal species and their cells retain some degree of totipotency and independence [6]. The basic body plan comprises of several different cell layers (Fig. 1). The outer surface, or pinacoderm, is formed by epithelial cells known as pinacocytes. Through pores (ostia) on the sponge surface, these cells also extend along the interior canals which permeate the sponge. Inside the sponge, specialized flagellated cells (choanocytes) form a series of chambers where feeding takes place. In these cho- anocyte chambers, collectively called the choanoderm, the movement of the choanocytes’ flagella pumps in water through the ostia and along the often elaborated aquiferous systems within the sponge. Choanocytes also filter food par- ticles (including bacteria and microalgae) from the water, and these are transferred to the mesohyl, an extensive layer *Address correspondence to this author at the Instituto de Microbiologia Paulo de Góes - Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, Cidade Universitária, 21941-590, Rio de Janeiro, Brazil; Tel: +5521-3938-8344; Fax: +5521-3938-8028; E-mail: marinella@micro.ufrj.br of connective tissue (Fig. 1). In the mesohyl, food particles are digested via phagocytosis by another group of sponge cells, the archaeocytes (or amebocytes). These totipotent cells are capable of differentiating into any of the other sponge cell types. Mesohyls present in many sponges repre- sent dense communities of microorganisms [6, 7]. The pres- ence of these microorganisms near the amebocytes suggests that the sponge cells either recognize different types of mi- croorganisms or that the latter have developed mechanisms to prevent being engulfed. Once filtered in the choanocyte chambers, the water is expelled through an opening at the top, the osculum [8]. In its natural habitat, the spatial distribution of Porifera is strongly influenced by water quality, especially with respect to its content of particles (organic and mineral), pollutants, and dissolved organic matter. Therefore, marine sponges are good indicators of water quality and have been used in envi- ronmental monitoring and bioremediation processes [9-11]. Sessile organisms such as sponges and other marine in- vertebrates, including corals and sea squirts, greatly rely on the production of chemical compounds as defense against natural predators, competitors, and invading organisms such as bacteria, viruses, and eukaryotes. Therefore, marine sponges have been attracting a particular interest in research, and a wide variety of natural products with different pharma- cological properties was identified and characterized [12]. Pharmaceutical interest in sponges began in 1950 with the discovery of the nucleosides spongothymidine and spon- gouridine, which were isolated from the marine sponge Cryptotethya crypta [13, 14]. These nucleosides formed the basis for the synthesis of ara-C, the first anticancer agent 18 - /14 $58.00+.00 © 2014 Bentham Science Publishers