Abstract
The influence of the fluorescent brightening agent (FBA), disodium 4, 4'-bisphenylureidostilbene-2, 2'-disulfonate, on Saccharomyces cerevisiae yeast was investigated in the presence of a series of polyoxyethylene alkylalcohol ethers (POEs). The nonionic surfactants changed the action of FBA on the yeast depending on their nature. Hydrophobic surfactants with FBA decreased more the growth of the yeast and the rate of surviving cells after incubation than with FBA alone, which was accompanied by stronger inhibition of sterol biosynthesis and of enzymes related to the electron-transport process. Extracellular enzymes were greatly enhanced in the presence of hydrophobic surfactants and FBA. On the other hand, the surfactants with low hydrophobicity exhibited the opposite action in reducing the influence of FBA on the biological processes in yeast. POEs had little effect on yeast. The effects of POE and FBA on the biochemical processes of yeast correlated well with the hydrophilic-lipophilic balance (HLB) of the surfactants. This phenomenon is interpreted in terms of the change in interaction of FBA in POE micelles with yeast, and is supported by data on adsorption isotherms of FBA to yeast in the presence of POE.
