Laboratório de Genética Molecular de Eucariontes e Simbiontes, Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ Brazil.
Genet Mol Biol. 2009 Jul;32(3):572-81. doi: 10.1590/S1415-47572009005000061. Epub 2009 Sep 1.
Nutrition in the Teredinidae family of wood-boring mollusks is sustained by cellulolytic/nitrogen fixing symbiotic bacteria of the Teredinibacter clade. The mangrove Teredinidae Neoteredo reynei is popularly used in the treatment of infectious diseases in the north of Brazil. In the present work, the symbionts of N. reynei, which are strictly confined to the host's gills, were conclusively identified as Teredinibacter turnerae. Symbiont variants obtained in vitro were able to grow using casein as the sole carbon/nitrogen source and under reduced concentrations of NaCl. Furthermore, cellulose consumption in T. turnerae was clearly reduced under low salt concentrations. As a point of interest, we hereby report first hand that T. turnerae in fact exerts antibiotic activity. Furthermore, this activity was also affected by NaCl concentration. Finally, T. turnerae was able to inhibit the growth of Gram-negative and Gram-positive bacteria, this including strains of Sphingomonas sp., Stenotrophomonas maltophilia, Bacillus cereus and Staphylococcus sciuri. Our findings introduce new points of view on the ecology of T. turnerae, and suggest new biotechnological applications for this marine bacterium.
蛀船蛤科（Teredinidae）的贝类通过栖居于其中的木质素降解/固氮共生细菌来获取营养，这些细菌属于栖瘤菌科（Teredinibacter）。红树蛀船蛤（Neoteredo reynei）是一种常见的用于治疗巴西北部传染性疾病的药用生物。在本研究中，严格局限于宿主鳃部的 N. reynei 共生菌被明确鉴定为转向栖瘤菌（Teredinibacter turnerae）。体外获得的共生菌变体能够以酪蛋白作为唯一的碳/氮源，并在较低浓度的 NaCl 下生长。此外，在低盐浓度下，T. turnerae 对纤维素的消耗明显减少。值得注意的是，我们首次报道转向栖瘤菌实际上具有抗生素活性。此外，这种活性也受到 NaCl 浓度的影响。最后，T. turnerae 能够抑制革兰氏阴性和革兰氏阳性细菌的生长，包括鞘氨醇单胞菌（Sphingomonas sp.）、嗜麦芽窄食单胞菌（Stenotrophomonas maltophilia）、蜡样芽孢杆菌（Bacillus cereus）和松鼠葡萄球菌（Staphylococcus sciuri）等菌株。我们的研究结果为转向栖瘤菌的生态学提供了新的观点，并为这种海洋细菌的生物技术应用提供了新的思路。
