Bolch Christopher J S, Subramanian Thaila A, Green David H
National Centre for Marine Conservation and Resource Sustainability, Australian Maritime College, University of Tasmania, Locked Bag 1370, Launceston, Tasmania, 7250, AustraliaScottish Marine Institute, Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, UK.
J Phycol. 2011 Oct;47(5):1009-22. doi: 10.1111/j.1529-8817.2011.01043.x. Epub 2011 Aug 29.
Interactions with the bacterial community are increasingly considered to have a significant influence on marine phytoplankton populations. Here we used a simplified dinoflagellate-bacterium experimental culture model to conclusively demonstrate that the toxic dinoflagellate Gymnodinium catenatum H. W. Graham requires growth-stimulatory marine bacteria for postgermination survival and growth, from the point of resting cyst germination through to vegetative growth at bloom concentrations (10(3) cells · mL(-1) ). Cysts of G. catenatum were germinated and grown in unibacterial coculture with antibiotic-resistant or antibiotic-sensitive Marinobacter sp. DG879 or Brachybacterium sp., and with mixtures of these two bacteria. Addition of antibiotics to cultures grown with antibiotic-sensitive strains of bacteria resulted in death of the dinoflagellate culture, whereas cultures grown with antibiotic-resistant bacteria survived antibiotic addition and continued to grow beyond the 21 d experiment. Removal of either bacterial type from mixed-bacterial dinoflagellate cultures (using an antibiotic) resulted in cessation of dinoflagellate growth until bacterial concentration recovered to preaddition concentrations, suggesting that the bacterial growth factors are used for dinoflagellate growth or are labile. Examination of published reports of axenic dinoflagellate culture indicate that a requirement for bacteria is not universal among dinoflagellates, but rather that species may vary in their relative reliance on, and relationship with, the bacterial community. The experimental model approach described here solves a number of inherent and logical problems plaguing studies of algal-bacterium interactions and provides a flexible and tractable tool that can be extended to examine bacterial interactions with other phytoplankton species.
与细菌群落的相互作用越来越被认为对海洋浮游植物种群有重大影响。在这里，我们使用了一个简化的甲藻-细菌实验培养模型，以确凿地证明有毒甲藻链状裸甲藻H. W. Graham从休眠孢囊萌发到在水华浓度（10³个细胞·mL⁻¹）下进行营养生长的整个过程中，萌发后存活和生长都需要具有生长刺激作用的海洋细菌。链状裸甲藻的孢囊在与抗抗生素或敏感抗生素的海杆菌属DG879或短杆菌属的单菌共培养中萌发并生长，以及在这两种细菌的混合物中生长。向用敏感抗生素菌株培养的培养物中添加抗生素会导致甲藻培养物死亡，而用抗抗生素细菌培养的培养物在添加抗生素后存活下来，并在21天的实验期后继续生长。从混合细菌的甲藻培养物中去除任何一种细菌类型（使用抗生素）都会导致甲藻生长停止，直到细菌浓度恢复到添加前的浓度，这表明细菌生长因子被用于甲藻生长或不稳定。对已发表的无菌甲藻培养报告的研究表明，对细菌的需求在甲藻中并不普遍，而是不同物种对细菌群落的相对依赖程度和关系可能有所不同。这里描述的实验模型方法解决了困扰藻类-细菌相互作用研究的一些内在和逻辑问题，并提供了一种灵活且易于处理的工具，可扩展用于研究细菌与其他浮游植物物种的相互作用。
