Reusch R, Hiske T, Sadoff H, Harris R, Beveridge T
Can J Microbiol. 1987 May;33(5):435-44. doi: 10.1139/m87-073.
Under growth-limiting conditions or conditions which mediate genetic transformation, Escherichia coli and Azotobacter vinelandii incorporate poly-beta-hydroxybutyrate into their plasma membranes. Genetic transformation competence of both bacteria increased in proportion to the concentration of membrane poly-beta-hydroxybutyrate. The effects of this lipid polymer on membrane structure were investigated by freeze-fracture electron microscopy. Before poly-beta-hydroxybutyrate incorporation, freeze-fracture revealed a typical mosaic of particles and pits on both concave and convex surfaces of the plasma membrane. As the cells incorporated the lipid polymer into the membrane, transformability developed and small semiregular plaques which possessed shallow particles were seen. These plaques grew in size and frequency as the membrane poly-beta-hydroxybutyrate concentrations and transformability increased.
在生长受限条件或介导遗传转化的条件下，大肠杆菌和棕色固氮菌将聚-β-羟基丁酸酯纳入其质膜。两种细菌的遗传转化能力均与膜聚-β-羟基丁酸酯的浓度成比例增加。通过冷冻断裂电子显微镜研究了这种脂质聚合物对膜结构的影响。在纳入聚-β-羟基丁酸酯之前，冷冻断裂显示质膜凹面和凸面上有典型的颗粒和凹坑镶嵌图案。随着细胞将脂质聚合物纳入膜中，转化能力逐渐形成，同时可见具有浅颗粒的小型半规则斑块。随着膜聚-β-羟基丁酸酯浓度和转化能力的增加，这些斑块的大小和频率也随之增加。
