Constitutive α-amylase producing mutant and recombinant haploid strains of thermophilic fungusThermomyces lanuginosus

摘要

Morphological, developmental and antimetabolite-resistant mutants ofT. languinosus were characterized and used for screening with the aim to develop constitutive α-amylase-hyperproducing strains. The protoplast fusion of two spontaneous mutants ofT. lanuginosus, characterized as asporulating and resistant to 2-deoxy-d-glucose (2DG), resulted in sporulating, 2DG sensitive heterokaryotic fusants. A recombinant haploid strain F64fB developed there from produced α-amylase constitutively in glucose-containing medium. Constitutive α-amylase-hyperproducing mutant (III8) obtained after cyclic mutagenesis and screening yielded ≈20 fold more α-amylase in a glycerol-containing medium than the wild strain.