Related Experiment Video
Updated: May 31, 2026
06:08
Design of Solid-State Fermentation Systems for Polymer Hydrolytic Extracellular Enzyme Production by Filamentous Fungi
Published on: June 6, 2025
Scale-down/scale-up studies leading to improved commercial beer fermentation
Alvin W Nienow1, Mikkel Nordkvist, Christopher A Boulton
1Centre for Bioprocess Engineering, University of Birmingham, UK. A.W.Nienow@bham.ac.uk
Biotechnology Journal
|July 12, 2011
Summary
Scale-up studies show mechanical agitation improves beer fermentation by reducing time and improving temperature control. A new rotary jet mixer offers these benefits at commercial scale without installation issues.
Area of Science:
- Biotechnology
- Chemical Engineering
- Food Science
Background:
- Scale-up/scale-down techniques are crucial for efficient and safe bioprocess design and operation.
- Previous studies in beer production highlighted yeast behavior under mechanical agitation.
- Commercial-scale fermentations often face challenges with yeast sedimentation and temperature control without proper mixing.
Purpose of the Study:
- To review and demonstrate the effectiveness of scale-up/scale-down studies in optimizing commercial bioprocesses, using beer production as a case study.
- To evaluate the impact of mechanical agitation on brewing yeast performance and fermentation kinetics.
- To introduce and assess a novel rotary jet mixer for improved mixing in commercial fermenters.
Main Methods:
- Bench-scale experiments investigating yeast response to mechanical agitation (up to 4.5 W/kg).
- Comparison of fermentation times between CO(2) evolution mixing and mechanical agitation (≥ 0.04 W/kg).
- Pilot-scale studies characterizing the mixing performance of a new rotary jet mixer in cylindroconical fermenters.
Main Results:
- Bench-scale agitation reduced fermentation time by approximately 20% without compromising yeast viability.
- Commercial-scale fermentations without agitation showed yeast sedimentation and poor temperature control.
- Stirrer mixing at commercial scale reduced batch time variability and improved temperature control, but installation is challenging.
- The rotary jet mixer demonstrated effective mixing, achieving similar batch time reductions as stirring without installation difficulties.
- The rotary jet mixer also enhanced fermentable sugar conversion to ethanol.
Conclusions:
- Scale-up/scale-down studies are highly effective for improving commercial bioprocess operations.
- The rotary jet mixer offers a practical solution for implementing efficient mixing in commercial fermenters, enhancing process control and product yield.
- Further research is recommended on homogenization's impact on vicinal diketone removal and bubble formation location in commercial-scale processes.
Related Concept Videos
01:14Scale-Up Processes
The scale-up of microbial fermentation processes is essential in industrial biotechnology, allowing the transition from laboratory-scale experiments to commercial-scale production while aiming to maintain product yield and quality. This process requires meticulous adjustment of equipment design, process parameters, and contamination control strategies to accommodate increasing culture volumes.At the laboratory scale, cultures are typically maintained in 1 to 10-liter glass or autoclavable...
01:22Bioreactor Controls-III
Strain improvement is a foundational strategy in industrial microbiology aimed at maximizing microbial productivity, particularly because natural isolates typically yield commercially valuable products in very low concentrations. Although optimizing the culture medium and environmental conditions can improve yields, these adjustments are inherently limited by the organism’s genetic potential. As a result, the focus shifts toward genetic modifications to enhance biosynthetic capacity. The...
01:25Microbes in Beverage Production
Alcoholic beverages such as wine, beer, and spirits are the products of microbial fermentation processes that transform simple sugars into ethanol and a wide array of complex flavor compounds. These transformations rely on the metabolic activities of specific yeasts and bacteria, which are selected and controlled to yield the desired beverage characteristics.Wine Fermentation and MaturationWine production begins with the crushing of grapes to release juice and pulp, forming a must that is...
01:27Production of Alcohol
Continuous fermentation is a key strategy in industrial ethanol production, particularly when efficiency, scalability, and high yields are essential. This approach allows for uninterrupted operation and optimized resource utilization. The primary feedstock, corn starch, undergoes enzymatic hydrolysis facilitated by α-amylase and glucoamylase. These enzymes break down the starch into fermentable sugars such as glucose, which are readily assimilated by fermentative microorganisms.Fermentation...
01:28Methods of Medium Optimization
Optimizing growth media enhances microbial proliferation and maximizes product yield. Statistical experimental design methodologies provide structured and reproducible approaches, offering progressively higher levels of robustness and efficiency.The One-Factor-at-a-Time (OFAT) MethodThe One-Factor-at-a-Time (OFAT) method involves adjusting a single variable while keeping all others constant. However, it cannot detect interactions between variables, often leading to suboptimal outcomes when...
01:29Microbes in Food Production
Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...