Effect of Cell Appendages on the Adhesion Properties of a Highly Adhesive Bacterium,Acinetobactersp. Tol 5

Abstract

A toluene-degrading bacterium, Acinetobacter sp. Tol 5, shows noteworthy adhesiveness mediated by two types of cell appendages. In this study, we obtained a less-adhesive mutant, T1, which lost both types of appendages, and investigated how the cell appendages affect the adhesion properties of this useful bacterium for environmental technology. Wild-type cells attained irreversible adhesion to polyurethane carriers within 30 s, while adhesion of T1 cells was still reversible at that time. While T1 showed decreased adhesion with decreasing ionic strength and did not adhere at all at 0.015 mM, adhesion of the wild type was fully independent of ionic strength. Acinetobacter sp. Tol 5 was also found to be not motile. Our results suggest that through the long distant interaction mediated by the appendages between the cells and surfaces, Tol 5 cells can attain irreversible adhesion very quickly without approaching the vicinity of the substratum.

Monolayer Adsorption of a “Bald” Mutant of the Highly Adhesive and Hydrophobic Bacterium Acinetobacter sp. Strain Tol 5 to a Hydrocarbon Surface

“…We have found that Tol 5 cells have filamentous appendages that are responsible for the high adhesiveness (16). Bald cells of a mutant strain (T1) of this bacterium lack these appendages and have weaker adhesiveness to solid surfaces (15). In the current report, we demonstrate a unique interaction between T1 cells and the liquid surfaces of organic solvents.…”

“…Adhesion to glassware should be minimized when the MATH test is employed in order to examine the interaction between microbial cells and hydrocarbons. According to the DerjaguinLandau-Verwey-Overbeek theory, which has been applied to microbial adhesion to solid surfaces (19), microbial adhesion decreases as the ionic strength decreases (15). Therefore, the use of pure water is expected to minimize cell adhesion to glassware.…”

Bacterial adhesion: From mechanism to control

“…Although two morphologically different nanofibers, namely, anchor-like and peritrichate pilus-like nanofibers, were initially found [62], at least three types of peritrichate nanofibers as well as the anchor on Tol 5 cells have been identified using state-of-the-art electron microcopy techniques. The less adhesive mutant T1 of this bacterium is defective in these nanofibers [63]. This mutant exhibits decreased adhesion with decreasing ionic strength and does not adhere at all at 0.015 mM, whereas adhesion of the wild type of Tol 5 is fully independent of ionic strength.…”

“…These observations imply that adhesion of Tol 5 cells deviates from the DLVO theory due to these nanofibers. In addition, the wild-type cells expressing these nanofibers attain irreversible adhesion immediately under conditions in which adhesion of T1 cells is still reversible [63]. Tol 5 cells are considered to be able to attain irreversible adhesion rapidly without approaching the vicinity of the substratum through the long distant interaction mediated by the nanofibers (Fig.…”

Two different mechanisms for adhesion of Gram-negative bacterium, Pseudomonas fluorescens LP6a, to an oil–water interface

“…The physicochemical and biological factors involved in adhesion are not yet clearly defined [1][2][3][4][5]. Factors affecting this process can be grouped into three categories: characteristics of microbial cells (including charge, hydrophobicity and composition of cell surface), properties of the oil surface, and environmental factors like ionic strength, pH and presence of specific compounds such as surfactants.…”