Williams V, Fletcher M
Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore 21202, USA.
Appl Environ Microbiol. 1996 Jan;62(1):100-4. doi: 10.1128/aem.62.1.100-104.1996.
The objectives of this work were (i) to use transposon mutagenesis to produce mutants of Pseudomonas fluorescens that were altered in adhesion ability and transport through porous media and (ii) to identify the alterations in surface characteristics that were responsible for the changes in attachment. Mutants of P. fluorescens were generated with TnphoA, which enabled identification of mutants that were altered in surface proteins. Transposon mutants were screened for alterations in adhesion ability by attachment assays on hydrophobic polystyrene and water-wettable polystyrene. Four TnphoA mutants with increased adhesion to the hydrophobic surface and decreased adhesion to the water-wettable surface were obtained. Transport of the strains through porous media was evaluated by passing suspensions of each mutant and the parent through columns containing quartz sand and determining the number of cells retained in the columns. The mutants all demonstrated increased adhesion and retention in the columns. Southern analysis demonstrated two types of mutants with separate transposon insertion sites. Polyacrylamide gel electrophoresis of the strains demonstrated that the O antigen on the lipopolysaccharide was either attenuated or absent. Lack of this polysaccharide, and the consequent increased exposure of the lipid moiety of the lipopolysaccharide, is probably responsible for the increase in adhesion to the hydrophobic substrata and retention in the sand column. This work combined with previous studies of attachment of P. fluorescens demonstrates that more than one type of polymer can mediate the adhesion of this organism to nonbiological surfaces.
（i）利用转座子诱变技术产生荧光假单胞菌的突变体，使其在黏附能力和通过多孔介质的迁移能力方面发生改变；（ii）确定导致黏附变化的表面特性改变。用TnphoA产生荧光假单胞菌的突变体，这能够鉴定出表面蛋白发生改变的突变体。通过在疏水聚苯乙烯和可被水润湿的聚苯乙烯上进行黏附试验，筛选转座子突变体在黏附能力方面的改变。获得了4个对疏水表面黏附增加而对可被水润湿表面黏附减少的TnphoA突变体。通过使每个突变体和亲本的悬浮液通过装有石英砂的柱子，并测定留在柱子中的细胞数量，评估菌株在多孔介质中的迁移情况。这些突变体在柱子中的黏附和滞留均增加。Southern分析表明有两种类型的突变体，其转座子插入位点不同。对这些菌株进行聚丙烯酰胺凝胶电泳显示，脂多糖上的O抗原要么减弱要么缺失。这种多糖的缺乏以及随之而来的脂多糖脂质部分暴露增加，可能是导致对疏水基质黏附增加和在砂柱中滞留增加的原因。这项工作与之前关于荧光假单胞菌黏附的研究相结合，表明不止一种类型的聚合物可以介导该生物体对非生物表面的黏附。
