ACCUMULATION OF PHOSPHORUS COMPOUNDS BY MUCOR RACEMOSUS

Area of Science:

• Microbiology
• Biochemistry
• Mycology

Background:

• Fungal nutrient assimilation is crucial for growth and metabolism.
• Phosphorus is an essential element for all living organisms, playing key roles in nucleic acids, ATP, and phospholipids.
• Understanding phosphorus metabolism in fungi like Mucor racemosus can provide insights into nutrient cycling and cellular energy management.

Purpose of the Study:

• To investigate the accumulation and utilization of phosphorus compounds by Mucor racemosus.
• To characterize the types of phosphorus compounds accumulated by the fungus under different nutrient conditions.
• To examine the relationship between phosphorus availability and fungal morphology and growth.

Main Methods:

• Culturing Mucor racemosus in glucose-inorganic salts media with varying phosphate concentrations.
• Analyzing the dry weight and phosphorus content of the fungal mycelium.
• Fractionating intracellular phosphorus compounds using biochemical methods.
• Observing morphological changes in hyphae under different growth conditions.

Main Results:

• Mucor racemosus accumulated significant amounts of phosphorus (5-6% dry weight) in media with excess inorganic phosphate.
• Inorganic polyphosphate constituted a major portion (approximately 58%) of the accumulated phosphorus in rapidly growing mycelium.
• Nucleic acids accounted for about 17% of the total phosphorus.
• Under phosphate limitation, mycelial phosphorus content decreased to approximately 0.3%, and the fungus utilized exogenous polyphosphate.
• Morphological changes and polyphosphate release into the media were observed during later growth stages.

Conclusions:

• Mucor racemosus exhibits a remarkable capacity for accumulating phosphorus, particularly as inorganic polyphosphate, under conditions of phosphate abundance.
• The fungus demonstrates metabolic flexibility by utilizing external polyphosphate when internal stores are depleted or external supply is limited.
• Phosphorus availability influences both the accumulation of phosphorus compounds and the morphology of Mucor racemosus.
• This study highlights the role of polyphosphate as a significant phosphorus reserve in Mucor racemosus.