Published articles:

Accepted for publication in PLOS One

The complete genome of Teredinibacter turnerae T7901: an intracellular endosymbiont of marine wood-boring bivalves (family Teredinidae)

Joyce C. Yang, A. Scott Durkin, Ramana Madupu, Nathan A. Ekborg, Bernard Henrissat, Sandra Schwartz, Joseph C. Mougous, Chandra S. Pedamallu, Lauren Fields, Amaro E. Trindade-Silva, Carlos A. G. Soares, Sherif Elshahawi, Amro Hanora, Margo G. Haygood, Janos Posfai, Jack Benner, Casey Swaim, John Nove, Brian Anton, Kshitiz Chaudhary, Jeremy Foster, Alex Holman, Sanjay Kumar, Philip A Lessard, Yvette A. Luyten, Barton Slatko, Nicole Wood, Bo Wu, John Zehr, Max Teplitski, Naomi Ward, Jonathan A. Eisen, Jonathan H. Badger, and Daniel L. Distel.

Abstract:

Here we report the complete genome sequence of Teredinibacter turnerae T7901. T. turnerae is a marine gamma proteobacterium that occurs as an intracellular endosymbiont in the gills of wood-boring marine bivalves of the family Teredinidae (shipworms). This species is the sole cultivated member of an endosymbiotic consortium thought to provide the host with enzymes, including cellulases and nitrogenase, critical for digestion of wood and supplementation of the host's nitrogen-deficient diet. T. turnerae is closely related to the free-living marine polysaccharide degrading bacterium Saccharophagus degradans str. 2-40 and to as yet uncultivated endosymbionts with which it coexists in shipworm cells. Like S. degradans, the T. turnerae genome encodes a large number of enzymes predicted to be involved in complex polysaccharide degradation (> 100). However, unlike S. degradans, which degrades a broad spectrum (>10 classes) of complex plant, fungal and algal polysaccharides, T. turnerae primarily encodes enzymes associated with deconstruction of terrestrial woody plant material. Also unlike S. degradans, T. turnerae dedicates a large proportion of its genome to genes predicted to function in secondary metabolism. Despite its intracellular niche, the T. turnerae genome lacks many features associated with obligate intracellular existence (e.g. reduced genome size, reduced %G+C, loss of genes of core metabolism) and displays evidence of adaptations common to free-living bacteria (e.g. defense against bacteriophage infection). Thus, the T. turnerae genome provides insights into the range of genomic adaptations associated with intracellular endosymbiosis as well as enzymatic mechanisms relevant to the recycling of plant materials in marine environments and the production of cellulose-derived biofuels.

In Progress:

Submitted

The microniche approach to discovering diverse actinomycete bacteria in cone snails

Olivier Peraud, Jason S. Biggs, Ronald W. Hughen, Alan R. Light, Gisela P. Concepcion, Baldomero M. Olivera and Eric W. Schmidt

Abstract:

Numerous studies have shown that actinomycetes can be symbionts in diverse organisms, including both plants and animals. Some actinomycetes benefit their host by producing small molecule secondary metabolites; the resulting symbioses are often developmentally complex. We examined the actinomycetes associated with three cone snails, venomous tropical marine gastropods which have been extensively examined because of their production of peptide-based neurological toxins but for which no microbiological studies have been reported. We used a microniche approach in which dissected tissue from each snail was treated as an individual sample in order to explore bacterial tissue specificity.
Our results revealed a diverse, novel and highly culturable cone snail-associated actinomycete community suggesting that cone snails represent a rich source for discovering new actinomycete symbionts. Additionally, we found evidence that symbiotic actinomycetes are localized to specific cells within cone snails, which could be a possible result of co-evolution.