The key difference between upstream and downstream bioprocessing is that upstream bioprocessing involves screening and identification of microorganisms, media preparation, multiplication of microbes inside a bioreactor, and incubation, while downstream bioprocessing involves extraction, purification and packaging of the product resulted from the fermentation.
Bioprocesses use living organisms, especially microorganisms such as bacteria and fungi, to produce valuable bioproducts which are industrially or medically important. Such bioproducts include antibiotics, vitamins, hormones, enzymes, and organic acids. Most bioprocesses are employed inside a bioreactor. Fermentation is the commonly used term to refer to a bioprocess carried out inside a bioreactor. Fermentation can be divided into two main processes/stages as upstream processing and downstream processing. The entire process up to the extraction of the product from the bioreactor comes under the upstream process, while steps such as extraction, purification, quality checking, and packaging, etc., which are done after the fermentation process, comes under the downstream process.
CONTENTS
1. Overview and Key Difference
2. What is Upstream Bioprocessing
3. What is Downstream Bioprocessing
4. Similarities – Upstream and Downstream Bioprocessing
5. Upstream vs Downstream Bioprocessing in Tabular Form
6. Summary – Upstream vs Downstream Bioprocessing
What is Upstream Bioprocessing?
The upstream process is one of the two main parts of a bioprocess. It includes the initial steps of a fermentation process. The preparation of microorganisms is the first step of upstream bioprocessing. The desired microbes should be isolated and selected for the bioprocess. Then they should be cultured in a suitable growth medium. Medium preparation is the second step. Optimal conditions, together with the nutrients, are supplied for the growth and multiplication of microorganisms inside a bioreactor.
Figure 01: Bioprocessing
Media preparation and optimization of growth conditions are two steps of upstream bioprocessing. Inoculation and running of the bioreactors until the completion of the fermentation process are the next levels of steps in the upstream bioprocessing.
What is Downstream Bioprocessing?
Downstream bioprocessing refers to the several final steps of a bioprocess that involve product harvest. The downstream process starts when the product development is completed. The steps include extraction, purification, and packaging of the final bioproduct of the bioprocess. Downstream bioprocessing is also known as product recovery. Amino acids, antibiotics, organic acids, vitamins, and vaccines are some of the bioproducts resulting from a bioprocess. The desired quality of the bioproduct is achieved during the downstream process. Volatile products can be purified using a distillation process. Moreover, biomass separation can be done by centrifugation. Therefore, the stages involving separation, extraction, purification, and polishing belong to downstream bioprocessing.
What are the Similarities Between Upstream and Downstream Bioprocessing?
- Upstream and downstream bioprocessing are the two main parts of a bioprocess.
- Living organisms, especially microorganisms, are involved in both processes.
- Industrially and medicinally important bioproducts undergo these processes.
- Both processes are equally important when manufacturing bioproducts.
- Contaminations should be prevented during both processes.
What is the Difference Between Upstream and Downstream Bioprocessing?
Product development takes place during the upstream bioprocessing, while product harvesting takes place during the downstream bioprocessing. Thus, this is the key difference between upstream and downstream bioprocessing. Moreover, isolation and selection of the microorganisms, development of the inoculum, media preparation, inoculation and incubation are the major steps of upstream bioprocessing. In contrast, extraction, purification, quality checking and packaging of the product are the major steps of downstream bioprocessing.
The following table tabulates the differences between upstream and downstream bioprocessing for side by side comparison.
Summary – Upstream vs Downstream Bioprocessing
Bioprocess or fermentation has two main stages: upstream bioprocessing and downstream bioprocessing. In upstream bioprocessing, microbes are screened, cultured, and grown inside a bioreactor, providing necessary nutrients and growth conditions. Downstream bioprocessing starts at the end of the inoculation period when the fermentation is completed. In downstream bioprocessing, extraction, purification, and proper packing of the product are done. Thus, this summarizes the difference between upstream and downstream bioprocessing.
Reference:
1. “Bioprocess.” Wikipedia, Wikimedia Foundation, 5 July 2021.
2. “Bioprocessing.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “Tanks-brewery-fermentation-5055929” (CC0) via Pixabay