• Saccharomyces cerevisiae and Its Role in Single Cell Protein (SCP) Production
  • Parsa Bozorgi,1 Nastaran Bozorgi,2,*
    1. Molavi High School, Department of Education Andimshek, Khuzestan, Iran
    2. Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Iran


  • Introduction: Saccharomyces cerevisiae is a unicellular fungus known as baker's yeast. It is usually larger than bacteria and differs in size. Its morphology is spherical or oval. It can reproduce sexually through germination or sexually through spore production. This has a nuclear genome consisting of 16 chromosomes. The genome of S.cerevisiae has been fully sequenced, revealing 6000 genes. Bioinformatics analysis indicates that of these 6000 genes, 5570 are protein-coding genes. S.cerevisiae has become widely used in the industry due to its potential for producing various products such as food, beverages, and bioethanol. Mycoproteins or Single Cell Protein (SCP) are natural protein concentrates produced by microorganisms like yeasts, algae, fungi, and bacteria. This article aims to explore the role of S.cerevisiae in SCP production and its impact on food safety and the environment.
  • Methods: Keywords such as food industry, SCP, and Saccharomyces cerevisiae were used to search online scientific databases like Google Scholar and PubMed, leading to the selection and review of related articles.
  • Results: Today, the continuous fermentation system is used to produce mycoprotein from yeast. Nutrients and inoculum are added to the cells under optimal growth conditions (temperature: 20-30°C, pH: 4.5-6.5) with continuous stirring, and a C/N ratio of 20-10. This is done at a consistent rate, while biomass and waste materials are harvested simultaneously. The culture is typically maintained in the exponential growth phase to achieve maximum production. After collection, it undergoes heat treatment to reduce its RNA content to below 2%. Then it is dehydrated and packaged. Saccharomyces cerevisiae can use inexpensive materials, such as agricultural waste, dairy, and lignocellulosic materials, as a source of carbon and nitrogen. The quality of SCPs produced by yeasts is similar to animal proteins and varies depending on the type of substrate. On average, they contain 50-60% protein, 2-6% fat, various amino acids, B vitamins, calcium, phosphorus, and glycogen. The first mycoprotein was produced from yeast in the 1970s under the brand "Pruteen" as an animal feed additive. "Quorn" is also a commercial brand of mycoprotein for animal feed. Since 1985, mycoproteins have been produced for human nutrition. Among the recombinant proteins produced by S.cerevisiae are glutathione, milk protein, Brazzein in the food field, transferrin, human hemoglobin, and human pancreas ribonuclease in the pharmaceutical field. They are also used as a meal for fish, as a supplement for livestock and ruminants (reducing intestinal CH4 emissions), and even as a suitable alternative for feeding astronauts on space missions.
  • Conclusion: One of the benefits of using yeast as an SCP producer is that they have low nucleic acid content and causes fewer side effects than animal proteins. Producing animal proteins requires cultivating large areas of agricultural land to feed the animals, which leads to the consumption of significant amounts of water and the emission of large quantities of greenhouse gases. In contrast, the nutritional needs of yeast are not complex, and they can also utilize waste as a resource. Yeast-produced single-cell protein boasts high protein content based on dry weight, low-fat content, a fast harvest cycle, and independence from seasons and weather conditions. However, it's important to note that products produced by microorganisms can trigger allergic and digestive reactions in some individuals. Today, due to the clarity and well-known genetic content of S.cerevisiae, along with many advances in molecular biology such as CRISPR/Cas9, the path of industrial and medical research in developing SCP production using S.cerevisiae has become smoother. Furthermore, Saccharomyces cerevisiae has been approved by the FDA for the production of heterologous proteins, food, pharmaceuticals, and industrial enzymes due to its strong safety record (non-toxic production). Today, vegetable and animal proteins alone cannot meet the world's demand for protein. It is necessary to increase the availability of new and stable protein sources. Microbial protein production should be used as an alternative method, and special attention should be paid to this issue in research and policies. Additionally, developing advertising campaigns to promote the benefits of SCP is effective in gaining high social acceptance.
  • Keywords: Saccharomyces cerevisiae, SCP, food industry