Department of Microbiology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1W5, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331.
Appl Environ Microbiol. 1990 Sep;56(9):2826-33. doi: 10.1128/aem.56.9.2826-2833.1990.
The binding characteristics of two octopine-catabolizing pseudomonads, Pseudomonas fluorescens B99A and E175D, which were isolated from crown galls, have been examined. The binding of strain B99A to potato disks was very weak, followed a Freundlich isotherm, and was temperature and pH independent. Strain E175D displayed strong attachment and followed a Langmuir isotherm. Despite these fundamental differences in binding characteristics, when each strain was placed in competitive binding assays with either Agrobacterium tumefaciens B6 or A. tumefaciens ATCC 15955, the number of bound pseudomonad cells decreased compared with those obtained in independent trials. Furthermore, the binding of A. tumefaciens cells was increased. In prebinding experiments, in which the potato disks were bound with the pseudomonads before exposure to the agrobacteria, the number of bound pseudomonad cells again decreased. This implies that increased desorption was occurring. In these prebinding studies, the numbers of bound A. tumefaciens ATCC 15955 increased, but the number of bound A. tumefaciens B6 remained the same. The mechanism for this observed synergism on the binding of agrobacterial cells and the depression in bound pseudomonad cells is believed to be alterations in the electrostatic or ionic charges on the plant and bacterial cell surfaces. The synergistic effect on A. tumefaciens undermines the use of these pseudomonads as potential biocontrol agents for crown gall.
两种分解胭脂碱的假单胞菌，荧光假单胞菌 B99A 和 E175D 的结合特性已经过研究。B99A 菌株与马铃薯片的结合非常弱，遵循弗莱德里希等温线，并且与温度和 pH 值无关。E175D 菌株表现出强烈的附着并遵循朗缪尔等温线。尽管结合特性存在这些根本差异，但当每种菌株与根癌农杆菌 B6 或根癌农杆菌 ATCC 15955 一起进行竞争性结合测定时，与独立试验相比，结合的假单胞菌细胞数量减少。此外，农杆菌细胞的结合增加了。在预结合实验中，在将马铃薯片与假单胞菌结合之前将其暴露于农杆菌，再次减少了结合的假单胞菌细胞的数量。这意味着发生了增加的解吸。在这些预结合研究中，结合的根癌农杆菌 ATCC 15955 的数量增加了，但结合的根癌农杆菌 B6 的数量保持不变。这种观察到的协同作用对农杆菌细胞结合的影响以及结合的假单胞菌细胞数量的减少的机制被认为是植物和细菌细胞表面的静电或离子电荷的改变。对根癌农杆菌的协同作用破坏了这些假单胞菌作为冠瘿病潜在生物防治剂的使用。
