Bioprocess optimisation for chitosan production by chitinolytic microorganisms

Area of Science:

• Biotechnology
• Environmental Science
• Microbiology

Background:

• Chitin-rich wastes are abundant in aquatic ecosystems.
• Chitinolytic microorganisms convert chitin into valuable chitosan.
• Microbial chitosan production offers a sustainable alternative to chemical methods.

Purpose of the Study:

• To isolate and characterize chitinolytic microorganisms from Nigerian freshwater and sediment.
• To optimize microbial chitosan production using controlled fermentation.
• To evaluate the potential of produced chitosan for agricultural and environmental applications.

Main Methods:

• Isolation and characterization of chitinolytic bacteria and fungi.
• Screening for chitinase activity and chitosan production.
• Optimization of fermentation parameters (temperature, pH, glucose, nitrogen, time) using central composite design and response surface methodology.

Main Results:

• Aspergillus niger showed the highest chitosan yield among isolated strains.
• Incubation time was the most significant factor influencing production.
• Optimized fermentation with Aspergillus niger yielded 1.46 g L⁻¹ chitosan with a high degree of deacetylation.

Conclusions:

• Inland aquatic ecosystems are rich sources of chitinolytic microorganisms.
• Optimized microbial fermentation provides an efficient and environmentally friendly route for scalable chitosan production.
• The produced chitosan is suitable for agricultural and environmental applications.