Vandevivere P, Baveye P
Department of Soil, Crop, and Atmospheric Sciences, Cornell University, Ithaca, New York 14853.
Appl Environ Microbiol. 1992 May;58(5):1690-8. doi: 10.1128/aem.58.5.1690-1698.1992.
Columns were packed with clean quartz sand, sterilized, and inoculated with different strains of bacteria, which multiplied within the sand at the expense of a continuous supply of fresh nutrient medium. The saturated hydraulic conductivity (HCsat) of the sand was monitored over time. Among the four bacterial strains tested, one formed a capsule, one produced slime layers, and two did not produce any detectable exopolymers. The last two strains were nonmucoid variants of the first two. Only one strain, the slime producer, had a large impact on the HCsat. The production of exopolymers had no effect on either cell multiplication within or movement through the sand columns. Therefore, the HCsat reduction observed with the slime producer was tentatively attributed to the obstruction of flow channels with slime. Compared with the results with Arthrobacter sp. strain AK19 used in a previous study, there was a 100-fold increase in detachment from the solid substratum and movement through the sand of the strains used in this study. All strains induced severe clogging when they colonized the inlet chamber of the columns. Under these conditions, the inlet end was covered by a confluent mat with an extremely low HCsat.
柱子用干净的石英砂填充、灭菌，然后接种不同的细菌菌株，这些细菌在砂中繁殖，消耗持续供应的新鲜营养培养基。随着时间的推移监测砂的饱和水力传导率（HCsat）。在测试的四种细菌菌株中，一种形成了荚膜，一种产生了黏液层，两种没有产生任何可检测到的胞外聚合物。后两种菌株是前两种的非黏液变体。只有一种菌株，即产生黏液的菌株，对HCsat有很大影响。胞外聚合物的产生对砂柱内的细胞繁殖或通过砂柱的移动均无影响。因此，观察到产生黏液的菌株导致HCsat降低，初步归因于黏液对流动通道的阻塞。与先前研究中使用的节杆菌属菌株AK19的结果相比，本研究中使用的菌株从固体基质上脱离并穿过砂的能力提高了100倍。当所有菌株在柱子的进水腔定殖时，都会导致严重堵塞。在这些条件下，进水端被一层HCsat极低的汇合菌垫覆盖。
