Photoautotrophic-heterotrophic biofilm communities: a laboratory incubator designed for growing axenic diatoms and bacteria in defined mixed-species biofilms
Photoautotrophic-heterotrophic biofilm communities: a laboratory incubator designed for growing axenic diatoms and bacteria in defined mixed-species biofilms
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DOI：
10.1111/j.1758-2229.2011.00315.x
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发表时间：
2012-02-01
影响因子：
3.3
通讯作者：
Schleheck, David
中科院分区：
文献类型：
--
作者：
Buhmann, Matthias;Kroth, Peter G.;Schleheck, David
水生生境真光区的生物膜群落包括光自养微生物，如硅藻、绿藻和蓝藻，它们产生的有机碳为一批异养微生物(主要是细菌)的生命提供燃料。由于缺乏合适的纯培养实验室模型系统，这种光自养-异养混合生物膜在生物膜研究中受到的关注很少。然而，它们提供了对生物膜发育过程中微生物种群动态和群落相互作用的重要洞察，生物膜发育过程形成了高度结构化、极其适应良好的微生物景观。在这里，我们报告了一种用于生长和监测无菌光养生物膜的无菌培养箱的开发，即用于纯培养物常规工作的可灭菌、有照明的连续流动系统。该系统被设计成模拟水生生境(水平水面、浸泡在水中、光照下、充气)的浅海地带的生长条件。这一概念的其他功能包括生物膜密度(如生物膜浑浊度)的自动光度监测、通过共焦显微镜进行分析、直接采集细胞以及控制光照、流速和培养液组成的选项。该系统在无菌硅藻生物膜的生长实验中得到了应用，该无菌硅藻生物膜与从贫营养淡水湖表层生物膜分离出的不同细菌菌株共培养。
Biofilm communities in the euphotic zone of aquatic habitats comprise photoautotrophic microorganisms, such as diatoms, green algae and cyanobacteria, which produce the organic carbon that fuels the life of a heterotrophic contingent of microorganisms, mostly bacteria. Such photoautotrophic-heterotrophic mixed-species biofilms have received little attention in biofilm research due to a lack of suitable pure-culture laboratory model systems. However, they offer important insight into microbial population dynamics and community interactions during a biofilm-developmental process that shapes highly structured, extremely well-adapted microbial landscapes. Here, we report on the development of a sterile incubation chamber for growing and monitoring axenic phototrophic biofilms, i.e. a sterilizable, illuminated, continuous-flow system for a routine work with pure cultures. The system has been designed to simulate the growth conditions in the shallow, littoral zone of aquatic habitats (horizontal surface, submerged in water, illuminated, aerated). Additional features of the concept include automated photometrical monitoring of biofilm density (as biofilm turbidity), analysis via confocal microscopy, direct harvesting of cells, and options to control illumination, flow velocity, and composition of culture fluid. The application of the system was demonstrated in growth experiments using axenic diatom biofilms, or axenic diatom biofilms co-cultivated with different bacterial strains isolated from epilithic biofilms of an oligotrophic freshwater lake.