Morphogenetic potency of short-chainn-alkanols related toAureobasidium pullulans dimorphism

Several concentrations ofn-alkanols from methanol to octanol have been added to cultures ofAureobasidium pullulans, and the minimal concentration inducing hyphal development (hyphae inducer concentration) for each one has been determined. An inverse relationship between inducer concentration and hydrocarbon chain length was observed up ton-hexanol (n-heptanol andn-octanol did not allow any growth). The morphogenetic inducer potency, defined as the inverse of the hyphae inducer concentration, was exponentially related to the chain length of the alcohol, as was the membrane/buffer partition coefficient. The morphogenetic inducer potency of the alcohols from methanol ton-hexanol was a function of their membrane solubility, all showing the same intramembrane inducer concentration.