MUTANTS OF THE CAROTENOID BIOSYNTHETIC-PATHWAY OF MUCOR-CIRCINELLOIDES

We have isolated and characterized a number of mutants affected in the biosynthesis of beta-carotene in the fungus Mucor circinelloides. Mut ants were obtained after mutagenesis with N-methyl-N-nitro-N-nitrosogu anidine or ultraviolet radiation. Carotene analysis and determination of in vitro activity for synthesis of prenyl pyrophosphates confirm th at we have obtained mutants for all enzymatic steps from farnesyl pyro phosphate to beta-carotene and regulatory mutants affecting total prod uction of carotenes and light regulation. (C) 1995 Academic Press, Inc .