Huggett Megan J, Williamson Jane E, de Nys Rocky, Kjelleberg Staffan, Steinberg Peter D
Centre for Marine Biofouling and BioInnovation, University of New South Wales, Sydney, 2052, Australia.
Oecologia. 2006 Oct;149(4):604-19. doi: 10.1007/s00442-006-0470-8. Epub 2006 Jun 23.
Bacterial biofilms are increasingly seen as important for the successful settlement of marine invertebrate larvae. Here we tested the effects of biofilms on settlement of the sea urchin Heliocidaris erythrogramma. Larvae settled on many surfaces including various algal species, rocks, sand and shells. Settlement was reduced by autoclaving rocks and algae, and by treatment of algae with antibiotics. These results, and molecular and culture-based analyses, suggested that the bacterial community on plants was important for settlement. To test this, approximately 250 strains of bacteria were isolated from coralline algae, and larvae were exposed to single-strain biofilms. Many induced rates of settlement comparable to coralline algae. The genus Pseudoalteromonas dominated these highly inductive strains, with representatives from Vibrio, Shewanella, Photobacterium and Pseudomonas also responsible for a high settlement response. The settlement response to different bacteria was species specific, as low inducers were also dominated by species in the genera Pseudoalteromonas and Vibrio. We also, for the first time, assessed settlement of larvae in response to characterised, monospecific biofilms in the field. Larvae metamorphosed in higher numbers on an inducing biofilm, Pseudoalteromonas luteoviolacea, than on either a low-inducing biofilm, Pseudoalteromonas rubra, or an unfilmed control. We conclude that the bacterial community on the surface of coralline algae is important as a settlement cue for H. erythrogramma larvae. This study is also an example of the emerging integration of molecular microbiology and more traditional marine eukaryote ecology.
细菌生物膜对于海洋无脊椎动物幼虫的成功附着越来越重要。在此，我们测试了生物膜对海胆红斑疣海胆附着的影响。幼虫可附着在许多表面，包括各种藻类、岩石、沙子和贝壳上。对岩石和藻类进行高压灭菌处理以及用抗生素处理藻类后，幼虫的附着率降低。这些结果以及基于分子和培养的分析表明，植物上的细菌群落对幼虫附着很重要。为了验证这一点，从珊瑚藻中分离出约250株细菌菌株，并将幼虫暴露于单菌株生物膜中。许多菌株诱导的附着率与珊瑚藻相当。假交替单胞菌属在这些高诱导性菌株中占主导地位，弧菌属、希瓦氏菌属、发光杆菌属和假单胞菌属的代表菌株也会引起较高的附着反应。对不同细菌的附着反应具有物种特异性，低诱导性菌株也以假交替单胞菌属和弧菌属的物种为主。我们还首次在野外评估了幼虫对已鉴定的单特异性生物膜的附着情况。与低诱导性生物膜红假交替单胞菌或无膜对照相比，幼虫在诱导性生物膜黄紫假交替单胞菌上变态的数量更多。我们得出结论，珊瑚藻表面的细菌群落作为红斑疣海胆幼虫的附着线索很重要。这项研究也是分子微生物学与更传统的海洋真核生物生态学不断融合的一个例子。
