Pollution potential reduction of cheese whey through yeast fermentation

Area of Science:

• Biotechnology
• Environmental Science
• Biochemistry

Background:

• Cheese whey is a significant industrial byproduct with high pollution potential.
• Valorization of cheese whey is crucial for sustainable waste management and resource recovery.
• Kloecknera (K.) fragilis is a yeast capable of metabolizing whey components.

Purpose of the Study:

• To investigate the kinetics of cheese whey fermentation using K. fragilis.
• To assess the reduction of pollution potential (COD, total solids, ammonium nitrogen) in cheese whey.
• To evaluate the production of single-cell protein (SCP) from cheese whey.

Main Methods:

• Design and construction of pilot-scale aerobic fermenters (4.8 L).
• Fermentation of cheese whey using K. fragilis under varying hydraulic retention times (6, 12, 18, 24 h).
• Analysis of key parameters: Chemical Oxygen Demand (COD), total solids, soluble solids, suspended solids, organic nitrogen, and ammonium nitrogen.

Main Results:

• Significant reductions in total COD (42%), soluble COD (65%), total solids (53%), and ammonium nitrogen (90%) were achieved.
• Increases in suspended solids (60%) and organic nitrogen (17%) indicated microbial biomass production.
• Hydraulic retention time significantly influenced pollution reduction and biomass yield, with 24h optimal for pollution control and 12h for soluble-to-insoluble conversion.

Conclusions:

• K. fragilis fermentation is effective for cheese whey valorization, reducing environmental impact and producing valuable biomass.
• Optimizing hydraulic retention time is key to balancing pollution reduction and single-cell protein production.
• Pilot-scale aerobic fermentation demonstrates a viable approach for sustainable cheese whey management.