Morphology engineering--osmolality and its effect on Aspergillus niger morphology and productivity

Area of Science:

• Biotechnology
• Industrial Microbiology
• Process Engineering

Background:

• Aspergillus niger is a key industrial microorganism with variable morphology impacting productivity.
• Controlling fungal morphology is crucial for optimizing yields in food and pharmaceutical production.

Purpose of the Study:

• To investigate the influence of osmolality on Aspergillus niger morphology and productivity.
• To establish a correlation between fungal morphology and enzyme production efficiency.

Main Methods:

• Conducted 50L stirred tank cultivations of Aspergillus niger strains.
• Utilized microscopy and digital image analysis to characterize fungal morphology.
• Developed a "Morphology number" for quantitative morphological assessment.
• Employed laser diffraction to determine fungal germination time.

Main Results:

• Increased culture broth osmolality by adding sodium chloride elevated specific productivity up to 18-fold for fructofuranosidase and glucoamylase.
• An optimal osmolality (around 3.2 osmol kg-1) was identified for maximal productivity, varying by strain.
• The "Morphology number" effectively correlated fungal morphology with productivity.
• Higher osmolality decelerated fungal germination.

Conclusions:

• Osmolality is an effective parameter for enhancing Aspergillus niger productivity in industrial settings.
• The "Morphology number" provides a reliable method for characterizing fungal morphology and its link to productivity.
• Customizing fungal morphology through osmolality control offers a promising strategy for optimizing industrial bioprocesses.