Change of cell wall chitin content in amphotericin B resistant Kluyveromyces strains

The culture of two Kluyveromyces species, Kluyveromyces lactis (ATCC 96897) and Kluyveromyces bulgaricus (ATCC 96631), in the presence of subinhibitory doses of amphotericin B leads to the selection of mutants which are resistant to this polyene. The mutants show an alteration of their cell wall composition with the main change corresponding to an increase of chitin. The enzyme activities involved in the metabolism of this polymer, i.e. chitin synthases and chitinase, were measured. The results demonstrate that in both mutants the activity of chitinase was drastically decreased by 99% in comparison with the activity measured in the corresponding wild-type strain while no significant change of the chitin synthase I, II and III activities could be detected.