44] Measurement of microbial adhesion to hydrophobic substrata

Abstract

Publisher Summary This chapter summarizes the most commonly employed method in determining adhesion to hydrophobins. The microbial adhesion to hydrocarbon (MATH) assay is based on the tendency of certain microorganisms to adhere to the surfaces of liquid hydrocarbon droplets, during a brief mixing period. The assay can be performed directly within a cuvette or tube that is compatible with a spectrophotometer, in which case the decrease in turbidity can be determined directly, provided that (1) the hydrocarbon droplets have risen completely from the aqueous phase, (2) care is taken to ensure that the upper phase does not interfere with the light beam, and (3) the walls of the vessel are free of interfering droplets. There are numerous factors involved in adhesion to hydrophobins, such as pH, ionic strength, temperature, age of cells, growth medium for the cells, time of incubation (or vortexing), antibiotics, and others. There is a good correlation among MATH and the other assays. For this reason and the fact that the method is simple and reproducible, MATH has become the assay of choice. The chapter also outlines other methods commonly employed to measure microbial cell surface hydrophobicity and adhesion to hydrophobins.