Development and Construction of a Laboratory-Scale Bubble Column Bioreactor for Immobilized Enzyme Fermentation Studies

This study presents the design and fabrication of a laboratory-scale bubble column fermenter specifically developed for fermentation studies employing immobilized enzymes. Constructed from stainless steel for durability and sterility, the fermenter incorporates advanced features to ensure precision and reliability. An air supply system, powered by a compressor, ensures consistent aeration, while precise temperature control is achieved through a jacketed reactor connected to a circulating water bath. These features are critical for maintaining optimal conditions for enzymatic reactions. To optimize the fermenter’s functionality, rate and design equations for bubble column fermenters were employed in calculating the operational parameters. The bioreactor boasts a working volume of 65 mL, a height of 80 mm, and an internal diameter of 10 mm, tailored for small-scale experimental setups. A custom-designed sparger with five evenly spaced 0.5 mm holes and a 0.2 mm spacing ensures uniform bubble formation. The generated bubble sizes, ranging from 0.5 mm to 3.93 mm, exhibited a controlled rise velocity of 0.1 cm/s, facilitating effective gas–liquid interactions critical for fermentation efficiency. Designed for a maximum operating temperature of 38°C, the system incorporates a compressor with a power rating of 0.152 kW, ensuring robust performance. Performance testing validated the fermenter’s utility, achieving a maximum ethanol production efficiency of 50.58%. This result underscores the system’s reliability for enzyme-mediated biochemical processes. The fabricated bubble column fermenter demonstrates significant potential as a versatile and efficient tool for both research and industrial applications in bioprocess engineering. By combining precision engineering with practical functionality, this study provides a valuable platform for advancing enzyme-based fermentation technologies, offering insights into scalable designs for broader biochemical and biotechnological applications.