Morris J Jeffrey, Kirkegaard Robin, Szul Martin J, Johnson Zackary I, Zinser Erik R
Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, USA.
Appl Environ Microbiol. 2008 Jul;74(14):4530-4. doi: 10.1128/AEM.02479-07. Epub 2008 May 23.
Axenic (pure) cultures of marine unicellular cyanobacteria of the Prochlorococcus genus grow efficiently only if the inoculation concentration is large; colonies form on semisolid medium at low efficiencies. In this work, we describe a novel method for growing Prochlorococcus colonies on semisolid agar that improves the level of recovery to approximately 100%. Prochlorococcus grows robustly at low cell concentrations, in liquid or on solid medium, when cocultured with marine heterotrophic bacteria. Once the Prochlorococcus cell concentration surpasses a critical threshold, the "helper" heterotrophs can be eliminated with antibiotics to produce axenic cultures. Our preliminary evidence suggests that one mechanism by which the heterotrophs help Prochlorococcus is the reduction of oxidative stress.
只有接种浓度较高时，原绿球藻属海洋单细胞蓝细菌的无菌（纯）培养物才能高效生长；在半固体培养基上形成菌落的效率较低。在这项研究中，我们描述了一种在半固体琼脂上培养原绿球藻菌落的新方法，该方法可将回收率提高到约100%。当与海洋异养细菌共培养时，原绿球藻在低细胞浓度下能在液体或固体培养基中茁壮生长。一旦原绿球藻细胞浓度超过临界阈值，就可以用抗生素消除“辅助”异养菌，以产生无菌培养物。我们的初步证据表明，异养菌帮助原绿球藻的一种机制是减轻氧化应激。
