This article provides an all-round insightful read about the different types of fermentor designs and the scope of applications, working principles and essentials of them in the industrial production.
What is a Fermentor?
Before we go into the types, one must have a proper idea of what a fermentor is. It is a specially designed bioreactor for the cultivation of microbes in controlled environment. It extends an ideal environment for growth of microbial or a cell culture subject to modification of factors like temperature, pH, O and nutrition supply. Although the words fermentor and fermentor are used synonymously, it describes the same crucial piece of bioprocessing equipment.
Importance of an Industrial Fermenter
The industrial fermenter is more than just a container, but a system, specially designed for rather consistent and large-scale biological manufacturing. The use of fermentor technology in the manufacture of the products has led many industries such as those dealing with pharmaceuticals and the food and beverage industries to scale processes effectively and in a sustainable manner. It also takes part in research and innovation in laboratories and, thus, finds new drugs and bio-products.
Batch Fermentors
Batch fermentors are some of the relatively straightforward fermentation systems. For a batch process, all the ingredients are loaded into the fermentor at the beginning and there are no further inputs made during the process. After all the fermentation process, all the contents including the dregs are drained off. Such a system is especially convenient for small-scale production or for the products vulnerable to contamination.
Batch systems offer:
- Simple operation and low cost
- Easy to clean and sterilize
- Can be used for many different microbial products
They however have low productivity as compared to continuous systems and have need for downtime when changing batches for cleaning and set-up.
Fed Batch Fermentors
This design combines the simplicity of the batch systems, and at the same time increases productivity. In the fed batch fermentation, there is no removal of culture broth hence the addition of the substrates is progressive with time. This helps in better control of nutrient concentration to avoid toxic accumulations and to allow long time of fermentation.
Fed batch fermentors are typical in the following:
- Antibiotic production
- Enzyme manufacturing
- Recombinant protein synthesis
They are especially convenient when one is dealing with activities involving substrate inhibition.
Continuous Fermentors
By using continuous fermentors, it is possible to be adding fresh medium in a continuous manner while removing spent medium and product also in a constant manner. This prevents the culture of the microorganisms from entering the stationary phase thereby maximizing on productivity.
Benefits of continuous fermentation include:
- High productivity
- Stable operating conditions
- Reduced downtime
On the negative side, continuous system is more complex and they need advanced control systems for them to attain steady state conditions. Anything contaminative can easily spread around and hence sterilization becomes necessary.
Stirred Tank Fermentors
In laboratory as well as industrial set up, the most commonly used is the stirred tank fermentor. It comprises cylindrical tank containing mechanical agitation in order for contents to be well mixed. These types of fermentors also have spargers for aeration purposes, baffles to stop vortexes and sampling and monitoring ports.
Stirred tank fermentors are flexible and they are applicable to the following:
- Aerobic and anaerobic fermentation
- Scale to the industrial levels from the laboratories.
- Manufacture of a variety of bio products
They have an advantage due to their robust design and scalability that makes them user friendly.
Airlift Fermentors
Unlike in mechanical mixture systems, Airlift fermentors employ use of air or gas whereas culture media are being circulated, omitting the need for mechanical agitation. These systems have riser and down comer section that develops circulation depending on differences in densities.
Applications of airlift fermentors include:
- Wastewater treatment
- Production of secondary metabolites
- Algae cultivation
These forms of systems are energy economical and create lower shear stress to cells hence suitable for sensitive cultures.
Packed Bed Fermentors
Packed bed fermentors, microbial culture is embedded to a solid support in the reactor. Liquid medium pass through the bed to transport products and take out the waste.
This type is ideal for:
- Immobilized enzyme production
- Bioconversion of waste materials
- Long-term continuous operations
Packed bed systems are able to provide high cell density and operational life without clogging; however, they have a problem with clogging and uneven flow distribution.
Fluidized Bed Fermentors
One of the modifications of the packed bed system, the fluidized bed fermentors use high flow rate for suspending the solid support particles in the liquid. This is advantageous for the purposes of enhancing mass transfer and preventing clogging.
They are suitable for those processes that involve:
- High transfer rates
- Continuous operation
- Stable performance over time
This system is more complicated as it demands a very strict regulation of fluid dynamics.
Submerged Fermentors
Submerged fermentors are, therefore, for the growth of microbes in a liquid nutrient medium. These are generally used in production of antibiotics, amino acids and enzymes. The design strives for aeration and agitation to achieve sufficient oxygen transfer which is, thus, achieved when the impeller chamber is filled to the three-quarter level.
These types of fermentors provide:
- High yield
- Rapid microbial growth
- Better control of parameters
They are readily implemented in the pharmaceutical and food production for large-scale production.
Solid State Fermentors
Unlike submerged systems, there is no free flowing liquid to grow the microbes in SSA fermentors but moisture in solid substrates. This method imitates natural microbes’ habitats and is applied to the fungi and a number of bacteria.
Applications include:
- Enzyme production
- Fermented food products
- Bio pesticides and composting
Solid state systems are cheap and comfortable hence energy efficient but they are difficult in scaling up and automation.
Photo Bioreactors
Specialized fermentors that are specially meant for photosynthetic microorganisms such as algae and cyanobacteria. These are the systems where light is used as the source of energy and they are made from the transparent material to allow penetration of light.
Uses include:
- Biofuel production
- Nutraceuticals
- Carbon dioxide sequestration
Photo bioreactors are able to be closed systems so that they do not become contaminated and more efficient.
Magnetically Driven Fermentors
These high-tech fermentors are equipped with the magnetic stirrers plugged in the vessel. They do not require shaft seals, eliminate the chances of contamination and are, therefore, recommended in sterile processes.
They are preferred in:
- Pharmaceutical manufacturing
- Cell culture applications
- High purity product production
They are more expensive, they are however more sterile and easier to clean.
Innovations in Fermentor Technology
The world of technology for fermentor is changing with a rapid pace. Now smart fermentors are equipped with built-in sensors, AI-based control system and remote monitoring opportunities. These innovations enhance efficiency in process and reduces the element of human error and facilitates real time decision making.
Emerging trends include:
- Single-use bioreactors
- Modular fermentor systems
- Green fermentation technologies
- Automated cleaning and sterilization
These developments are helping to strengthen the spread of bioprocessing in industries that have not been touched upon by the fermentation science.
Environmental Impact
It is beneficial to work with industrial fermenter for the purposes of sustainability in production. Most of them use waste products as the feedstock and generate less emissions in comparison to traditional manufacturing of chemicals. They also promote the manufacturing of biodegradable plastics, bioethanol, as well as plant-based proteins.
Final Thoughts
It is important to appreciate the various variety of designs of the fermentor, applications to harness the potential. There is basic types of fermentor, there is advanced photo bioreactor, all of these are employed for different uses in industrial biotechnology.
Through the proper industrial fermenter investment, businesses will be able to increase productivity, cut on cost, and become green. To those in need of expert solutions, BaiLun Bio has state of the art equipment that is a mix of both innovation and reliability.
FAQs
- Which of the fermentors is the most frequently used?
The most frequently used type of fermentor is the stirred tank one because of its capacity to be scaled; versatility.
- Where and what industries do they apply the industrial fermenters?
Pharmaceutical, food and beverage, biofuels and agriculture are among industries that use the industrial fermenters in their production.
- What should I do in order to make the most appealing choice of fermentors for my business?
Account for product type, process requirements, scale, and regulatory requirements. Seek advice from a manufacturer such as BaiLun Bio a on professional advice.
- Are types of fermentors able to contribute to the sustainable production?
Yes. Several types of fermentors promote eco-friendly processes because they use renewable feedstock’s and minimize wastes of chemical nature.