Submerged Fermentation
The biological process of turning complicated substrates into simple chemicals by a variety of microorganisms, including bacteria and fungus, is known as fermentation. They emit a number of other substances during this metabolic breakdown in addition to the typical byproducts of fermentation, such as carbon dioxide and alcohol. These extra substances are referred to as secondary metabolites. Many different antibiotics, peptides, enzymes, and growth hormones are examples of secondary metabolites. The advancement of processes like Solid State Fermentation (SSF) and Submerged Fermentation (SmF) has enabled the manufacture of bioactive chemicals at an industrial scale.
Submerged fermentation
In the process of producing biomolecules known as “submerged fermentation,” enzymes and other reactive substances are immersed in a liquid such as alcohol, oil, or nutritional broth.
Liquid fermentation (LF) and submerged fermentation (SmF) both use freely flowing liquid substrates such as broths and molasses. The method is employed for many different things, mostly in industrial manufacturing.
Submerged Fermentation Principle
When a microbe ferments submerged, it grows as a suspension in a liquid medium that contains a variety of nutrients that are either dissolved or suspended as particulate solids in many commercial media. A method known as submerged fermentation involves the growth of microorganisms in a liquid broth. This liquid broth produces industrial enzymes, antibiotics, and other goods in addition to providing nutrients. The procedure entails adding a particular microorganism, such as fungus, to a tiny, closed flask filled with nutrient-rich broth. Additionally, the procedure needs a lot of oxygen. When the microorganisms in the broth interact with the nutrients, breaking them down, enzymes are then produced. The fermentation broth is where the bioactive substances are released.
Techniques for Submerged Fermentation
Batch-fed fermentation and continuous fermentation are the two most often used techniques for submerged fermentation. In batch-fed fermentation, the culture is supplemented with sterile growth ingredients. As it happens during the growth of biomass in the fermenter, it is most prevalent in the bio-industry. It is normally highly concentrated to prevent dilution and aids in increasing cell density in the bioreactor. By supplying nutrients, the culture’s development rate is maintained, and the risk of overflow metabolism is decreased. The fermentation process is carried out continuously in an open system. The converted nutrient solution is then slowly and continually collected from the bioreactor while sterilized liquid nutrients are introduced.
Examples of Submerged Fermentation Applications
- The main use of SmF is the liquid-form extraction of secondary metabolites.
- Enzymes originating from microorganisms are typically produced by submerged liquid fermentations.
Submerged fermentation benefits
- The benefits of submerged fermentation techniques are quick turnaround, low cost, and high yield.
- Product purification is simpler.
- Because fermentation can be more easily controlled in liquid culture, fermentation times can be cut down significantly.
- Similar to how solid-state technologies need more labor, submerged culture can increase the production of several secondary metabolites while lowering production costs.
Submerged fermentation’s drawbacks
- Recent studies have shown that SSF has a significant impact on productivity, resulting in higher yields and better product qualities than SmF.
- Ineffective volumetric productivity
- Comparatively lower product concentration
- Increased wastewater production
- Sophisticated fermentation apparatuses
