PDF(Pubmed)
Abstract：
The adsorption behaviour of micro-organisms during the initial attachment stage of biofilm formation affects subsequent stages. The available area for attachment and the chemophysical properties of a surface affect microbial attachment performance. This study focused on the initial attachment behaviour of Klebsiella aerogenes on monazite by measuring the ratio of planktonic against sessile subpopulations (P:S ratio), and the potential role of extracellular DNA (eDNA). eDNA production, effects of physicochemical properties of the surface, particle size, total available area for attachment, and the initial inoculation size on the attachment behaviour were tested. K. aerogenes attached to monazite immediately after exposure to the ore; however, the P:S ratio significantly (p = 0.05) changed in response to the particle size, available area, and inoculation size. Attachment occurred preferentially on larger-sized (~50 µm) particles, and either decreasing the inoculation size or increasing the available area further promoted attachment. Nevertheless, a portion of the inoculated cells always remained in a planktonic state. K. aerogenes produced lower eDNA in response to the changed surface chemical properties when monazite was replaced by xenotime. Using pure eDNA to cover the monazite surface significantly (p ≤ 0.05) hindered bacterial attachment due to the repulsive interaction between the eDNA layer and bacteria.
摘要：
在生物膜形成的初始附着阶段，微生物的吸附行为会影响后续阶段。可用于附着的面积和表面的化学物理性质影响微生物附着性能。本研究通过测量浮游与固着亚群的比例（P：S比），重点研究了产气克雷伯氏菌在独居石上的初始附着行为。以及细胞外DNA（eDNA）的潜在作用。eDNA生产,表面的物理化学性质的影响，颗粒大小,总可用附件面积，并测试了初始接种大小对附着行为的影响。K.曝气剂在暴露于矿石后立即附着在独居石上；然而，P:S比显著(p=0.05)随颗粒大小而变化，可用区域,和接种量。附着优先发生在较大尺寸(~50µm)的颗粒上，并且减小接种大小或增加可用面积进一步促进附着。然而，一部分接种的细胞始终保持浮游状态。当独居石被异种时间取代时，K.曝气生物产生的eDNA含量较低，以响应表面化学性质的变化。由于eDNA层与细菌之间的排斥相互作用，使用纯eDNA覆盖独居石表面显着（p≤0.05）阻碍了细菌的附着。
