Respiratory-competent conditional developmental mutant of Mucor racemosus

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Mucor racemosus exhibits dimorphism, switching between yeast and mycelial forms.
• Oxygen availability influences its morphology and metabolic pathways.

Purpose of the Study:

• To characterize a conditional developmental mutant of Mucor racemosus.
• To investigate the role of oxygen in regulating gene expression for metabolism and morphogenesis.

Main Methods:

• Generation and characterization of a conditional developmental mutant.
• Aerobic growth experiments using glucose and amino acids as carbon sources.
• Enzyme assays for glycolytic and tricarboxylic acid cycle enzymes.
• Analysis of protein expression patterns.

Main Results:

• The mutant displayed high fermentative activity and yeast morphology under aerobic conditions with glucose.
• Aerobic growth on amino acids induced mycelial morphology.
• Maximal glycolytic enzyme expression correlated with fermentative activity and yeast form.
• The mutant maintained oxidative metabolism capabilities.

Conclusions:

• Oxygen regulates both glycolytic enzyme expression and morphogenesis in Mucor racemosus.
• Common regulatory elements likely control these two processes.
• Citrate pool sizes may act as oxygen-responsive gene regulators.