Identification of mutations preventing n-hexadecane uptake among 26 n-alkane non-utilizing mutants of Yarrowia (Saccharomycopsis) lipolytica

Summary Genetic analyses of n-alkane non-utilizing mutants of the yeast Yarrowia (Saccharomycopsis) lipolytica were continued. By analyses of inter-mutant complementation and recombination a total of 26 genetic loci have been identified. Mutations representing these loci have phenotypes characteristic of defects in substrate uptake or in one or more of the enzymatic activities making up the hydroxylase complex. Tests of ¹⁴C n-hexadecane uptake by a set of alkane-negative mutants representing the 26 loci show that 16 of the mutations cause a significant reduction in n-alkane uptake. N-alkane uptake by Y. lipolytica is shown to be inducible and to be inhibited by the metabolic poisons 2–4 dinitrophenol and KCN. The latter observation indicates that n-alkane uptake of Y. lipolytica is due to active transport.