[Conditions for dextranase formation by Paecilomyces lilacinus]

Area of Science:

• Microbiology
• Enzymology
• Biotechnology

Background:

• Dextranase is an enzyme that degrades dextran.
• Paecilomyces lilacinus is a fungus known to produce various enzymes.
• Optimizing enzyme production is crucial for industrial applications.

Purpose of the Study:

• To investigate the optimal conditions for induced dextranase formation by Paecilomyces lilacinus.
• To determine the effect of different carbon sources, particularly dextran molecular weight, on enzyme production.
• To identify other key medium and culture parameters for enhanced dextranase yield.

Main Methods:

• Screening various carbohydrates as carbon sources and inducers.
• Comparing the impact of different dextran molecular weights (17.2–1000 kD) on enzyme formation.
• Evaluating the effects of nitrogen source, initial pH, temperature, inoculum size, and cultivation time.
• Utilizing shaker flask cultivation for enzyme production.

Main Results:

• Dextran was identified as the most effective carbon source and inducer for dextranase formation.
• Enzyme productivity significantly increased with higher molecular weight dextran, with 1000 kD dextran yielding 40% more enzyme than 17.2 kD dextran.
• Addition of other sugars repressed enzyme formation.
• Optimal conditions were determined as beef peptone (N-source), initial pH 6.0-7.0, 28°C, 10% inoculum, and 6 days of cultivation at 200 rpm.

Conclusions:

• High molecular weight dextran is a superior inducer for dextranase production by Paecilomyces lilacinus.
• Specific medium composition and culture parameters are critical for maximizing enzyme yield.
• The findings provide a basis for optimizing industrial-scale dextranase production.