Abstract
SUMMARY: Mutants resistant to growth inhibition have been obtained by selecting on media containing inhibitory concentrations of either d-glucosamine or l-sorbose. All of the mutants isolated were found to be sugar transport-defective and cross-resistant to growth inhibition by the three analogues 2-deoxy-d-glucose, d-glucosamine and l-sorbose. Like the mutants previously selected for resistance to 2-deoxy-d-glucose, the new mutants described are all shown to be alleles of the ftr cistron.