THE IMPACT OF STORM-FLOW ON RIVER BIOFILM ARCHITECTURE
THE IMPACT OF STORM-FLOW ON RIVER BIOFILM ARCHITECTURE
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DOI：
10.1111/j.0022-3646.1994.00807.x
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发表时间：
1994-10-01
影响因子：
2.9
通讯作者：
LOCK, MA
中科院分区：
文献类型：
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作者：
BLENKINSOPP, SA;LOCK, MA
采用透射电镜（TEM）和扫描电镜（SEM）研究了暴雨流对河流生物膜结构的影响。TEM树脂基质在光生长（LG）或暗生长（DG）条件下在北威尔士的Clywedog河中定殖33周，然后暴露于环境流（约1000 μ m）。60 cm.s（-1））或暴雨流（约235 cm.s（-1）+河流沉积物），线样方法被用来量化LG材料的TEM切片的信息。在LG环境流生物膜，细菌更丰富的直接相邻的底层，并显着密集的直接下的贴生硅藻Cocconeis。在生物膜的更高处，细菌松散地分散在其他细胞之间的基质中。蓝细菌最常出现，作为单细胞，但也发现在大的“栅栏”形成邻近的基层。显着的水平和垂直最近的邻居协会指出，细菌和蓝藻。卵形藻的细胞通常邻近于为细菌、蓝藻和密集染色的胞外多糖的“有机垫”提供庇护的基质，并且通常被升高。蓝藻和卵形藻是耐去除风暴流，但卵形藻硅藻壳有时会受到损害。在LG风暴流样品中的细菌不太常见的邻近的底层，有时更分散的生物膜比在环境流样品中更高。我们认为，风暴流的水动力可能会重新分配细菌相邻的底层到更高的地区的生物膜。此外，细菌和胞外多糖基质有时被风暴流向下移动到底层，除非在卵形藻下面。DG生物膜几乎完全由细菌组成。风暴流只去除表面生长的DG生物膜，和SEM显示peritrich茎磨损和“吹落。干扰前的生物膜结构似乎会影响破坏的形式。我们认为，“缩影”的Cocconeis和他们的底层细胞不仅作为接种物，以使表面在条件允许的情况下，但通过中断整个表面的流动模式，提高移民。
The impact of storm-flow on river biofilm architecture was investigated using transmission (TEM) and scanning (SEM) electron microscopy. TEM resin substrata were colonized under light-grown (LG) or dark-grown (DG) conditions for 33 weeks in the Clywedog River, North Wales, prior to exposure to ambient-flow (approx. 60 cm.s(-1)) or storm-flow (approx. 235 cm.s(-1) + river sediment) in a laboratory flume, Line transect methodology was used to quantify information from TEM ultrathin sections of LG material. In the LG ambient-flow biofilm, bacteria were more abundant directly adjacent to the substratum and were noticeably denser directly under the adnate diatom Cocconeis. Higher in the biofilm, the bacteria were loosely dispersed in the matrix between other cells. Cyanobacteria occurred most frequently, as single cells but were also found in large ''palisade'' formations adjacent to the substratum. Significant horizontal and vertical nearest-neighbor associations were noted for both bacteria and cyanobacteria. Cells of Cocconeis were common adjacent to the substratum providing shelter to, and often elevated upon, an ''organic pad'' of bacteria, cyanobacteria, and densely staining exopolysaccharide. Cyanobacteria and Cocconeis were resistant to removal by storm-flow, but Cocconeis frustules were sometimes damaged. Bacteria in the LG storm-flow samples were less common adjacent to the substratum and were sometimes more dispersed higher in the biofilm than in ambient-flow samples. We suggest that storm-flow hydrodynamic forces may redistribute bacteria adjacent to the substratum into higher areas of the biofilm. In addition, bacteria and the exopolysaccharide matrix were sometimes removed down to the substratum by storm-flow, unless beneath Cocconeis. The DG biofilm consisted almost entirely of bacteria. Storm-flow only removed surface growth from DG biofilms, and SEM revealed peritrich stalk abrasion and ''blow-down.'' Pre-disturbance biofilm architecture appears to influence the form of destruction. We suggest that the ''microcosms'' of Cocconeis and their underlying cells not only serve as an inoculum to recolonize the surface when conditions permit but enhance immigration by interrupting flow patterns across the surface.