What is Fermentation?
Fermentation, a centuries-old process, serves the dual purpose of preserving and enhancing the nutritional value of different foods. Within a controlled environment—such as a sealed jar—microorganisms induce chemical transformations in food composition. For example, consider the transformation of grapes into wine. Here, yeast is combined with grape juice and, as part of their metabolic cycle, these microorganisms consume available sugars and yield ethanol and carbon dioxide as byproducts. However, these byproducts are far from waste! They enable the creation of tasty foods like yogurt, cheese, beer, kombucha, and sourdough bread.
How is Precision Fermentation Different?
The fundamental distinction between precision fermentation and its traditional counterpart lies in inputs and outputs. While traditional fermentation results in outputs that mirror the inputs (as seen with grapes to wine), precision fermentation has the capability to generate entirely novel outputs (such as human insulin).
The History of Precision Fermentation and Recombinant Proteins
Although the use of precision fermentation within the food industry is relatively recent, the technology itself dates back to the 1980s. The first product derived from precision fermentation was recombinant human insulin, synthesised using E. coli. Previously, insulin for diabetic patients was extracted from bovine or porcine pancreas, which, while effective, carried a notable risk of allergic reactions. However, in 1982, American biologist David Goeddel successfully developed human insulin using recombinant DNA technology.
This approach empowers scientists to guide microorganisms into generating a specific product. External DNA containing precise instructions is merged with the microbial cell’s DNA. The outcome is a genetically engineered DNA fragment that integrates into the host cell, effectively transforming it into a production facility for the desired product. Given the rapid multiplication of microorganisms, end products can be produced swiftly and in substantial quantities. The resulting product is termed a “recombinant protein” due to the fusion of external and microbial DNA.
The Process:
- Genetic Code: DNA is encoded with the gene to produce the target protein
- Microbial Host Insertion: The DNA is inserted and induced to secrete large amounts of the target protein
- Fermentation: The host cells are immersed in a nutrient-rich media which provides them with the necessary nutrients for growth. This mixture is placed inside a bio-reactor which maintains the optimal conditions for cellular growth (in terms of oxygen levels, temperature and pH)
- Downstream Processing and Purification: The target protein is recovered from the cell/media mixture and refined to produce the functional product at high purity.
- High Purity End Ingredient: The protein powder is used as a key ingredient to recreate the functionality of products containing dairy and eggs
Application in Food Production:
The application of precision fermentation in food production parallels its use in pharmaceuticals. For the production of dairy proteins, DNA is modelled to mimic the sequencing of cow DNA. This DNA is then combined with the microbe’s plasmid DNA, resulting in the production of the desired protein. Should both major milk proteins—caseins and whey proteins—be synthesised, they can be employed in the creation of milk, cheese, or any other dairy-based protein product. This approach facilitates the production of dairy items without relying on animal husbandry. Not only does this alleviate animal suffering, but it reduces the demand for antibiotics and presents a solution to the supply chain volatility of animal protein.