Protease-deficient Mutants of Pseudomonas aeruginosa: Pleiotropic Changes in Activity of Other Extracellular Enzymes

Abstract

Thiamin-deficient mutants of Bacillus subtilis were characterized by their growth responses to the pyrimidine and thiazole moieties of the vitamin molecule and by cross-feeding tests. All mutants growing on the thiazole moiety and all mutants with an absolute requirement for thiamin fed all those growing on the pyrimidine moiety. No other cross-feeding effects were observed. From the culture fluid of a mutant growing on the thiazole moiety, two compounds were isolated which supported growth of mutants requiring the pyrimidine moiety. These compounds were identified by chromatographic, bioautographic and spectrophotometric procedures as 4-amino-5-hydroxymethyl-2-methylpyrimidine and its monophosphate derivative.