Böhme Anne, Risse-Buhl Ute, Küsel Kirsten
Institute of Ecology, Friedrich Schiller University Jena, Jena, Germany.
FEMS Microbiol Ecol. 2009 Aug;69(2):158-69. doi: 10.1111/j.1574-6941.2009.00710.x. Epub 2009 May 12.
The effect of Dexiostoma (filter feeder), Vannella, Chilodonella (raptorial feeders), Spumella, and Neobodo (direct interception feeders) on the morphology of multispecies bacterial biofilms was investigated in small flow cells. The filter feeder Dexiostoma campylum did not alter biofilm volume and porosity but stimulated the formation of larger microcolonies compared with ungrazed biofilms. In contrast, the raptorial feeder Vannella sp. efficiently grazed bacteria from the biofilm surface, leading to smaller microcolonies and lower maximal and basal layer thickness compared with ungrazed biofilms. Microcolony formation was not stimulated in the presence of the sessile Spumella sp. Chilodonella uncinata rasped bacteria from the outer surface leading to mushroom-shaped microcolonies. In the presence of C. uncinata and Spumella sp., the biofilm volume was 2.5-6.3 times lower compared with ungrazed biofilms. However, the biofilm porosity and the ratio of biofilm surface area to biofilm volume were 1.5-3.7 and 1.2-1.8 times higher, respectively. Thus, exchange of nutrients and gases between the biofilm and its surrounding fluid should also be improved in deeper biofilm layers, hence accelerating microbial growth.
在小型流动槽中研究了右旋口虫（滤食性生物）、帆口虫、斜管虫（捕食性生物）、陀螺虫和新波豆虫（直接截留捕食性生物）对多物种细菌生物膜形态的影响。滤食性生物右旋口虫未改变生物膜体积和孔隙率，但与未被摄食的生物膜相比，刺激了更大微菌落的形成。相比之下，捕食性生物帆口虫属有效地从生物膜表面摄食细菌，与未被摄食的生物膜相比，导致微菌落更小，最大和底层厚度更低。在固着的陀螺虫存在的情况下，微菌落形成未受到刺激。斜管虫从外表面刮擦细菌，导致形成蘑菇状微菌落。在斜管虫和陀螺虫存在的情况下，生物膜体积比未被摄食的生物膜低2.5至6.3倍。然而，生物膜孔隙率以及生物膜表面积与生物膜体积之比分别高1.5至3.7倍和1.2至1.8倍。因此，生物膜与其周围流体之间的营养物质和气体交换在较深的生物膜层中也应该得到改善，从而加速微生物生长。
