by Vandana Mishra
Proteins are everywhere in our lives, from the milk we drink, to the eggs in breakfast, the cheese on pizza, or even the burgers we enjoy on weekends. They don’t just give us nutrition, they also shape the texture of food and sometimes even its flavor. While I started working as a protein scientist, I was struck by how deeply we depend on animals, and I wondered how we can improve upon the process of producing them. Globally about 65% of protein comes from plants, but in the U.S. nearly 70% still comes from animals and dairy. It also raises an important question whether our present food system meets the protein needs of a growing population. As the world population is expected to reach about 9.7 billion by 2050, we’ll need to produce about 80% more protein than we do today to keep up with global demand. Beyond protein needs, livestock production drives deforestation, uses vast land and water resources, emits high levels of greenhouse gases, and raises concerns about animal welfare [1][2].
Protein-rich foods like milk, eggs, and meat have long been tied to nutrition, culture, and comfort. But how can we keep enjoying the foods we love without relying so heavily on animals. One promising solution is to use plant proteins from foods like beans, lentils, and soy, which can be processed to mimic the texture, taste, and nutritional profile of animal proteins. Another rapidly emerging technology is Precision fermentation (PF), that uses microbes such as yeast (Pichia pastoris), fungi (Trichoderma reesei), and bacteria (Bacillus subtilis) to produce specific proteins found in milk, eggs, or meat, but without the animal. For example, milk has fats, sugars, and proteins, but two prominent class of proteins, caseins and whey give it most of its structure and nutrition. In PF process, scientists identify the gene that makes one of these proteins, like beta-lactoglobulin (a major whey protein in cow’s milk), and place it inside a microbe. The microbe’s own cellular machinery then reads this gene and produces the protein, just as it makes its own. Fermentation, of course, isn’t new, people have used it for centuries to turn milk into yogurt, grains into beer, or sweet tea into kombucha where microbes convert one substance into another. Importantly, the microbes used in PF are species with a long history in food and are generally classified as safe (GRAS), meaning they are not harmful when the process is properly controlled. For instance, rennet for cheese, once taken from calf stomachs, has been produced in microbes since the 1990s and now accounts for about 90% of global supply [3][4].
Microbes can be grown in large fermenters to produce food proteins at scale. Compared with livestock, PF can yield 30 to 100 times more protein per hectare while using far less land, water, and time. Studies suggest it could cut land, water use, and global warming potential by up to 87%, 84%, and 83%, respectively compared with today’s European diets. Producing a single kilogram of meat or milk protein usually takes about 7 kilograms of plant feed, along with heavy land and water inputs. Microbes skip that step, and some systems can even use fruit peels or crop residues as inputs, to make the process more sustainable. Unlike animal farming, microbial protein production does not depend on weather or climate, and once facilities are built it can be scaled even in places with limited farming [4][5][6].
Safety is critical when producing food from microbes and keeping unwanted microbes out of the fermenter is one of the key tasks. Industrial tanks are kept sterile by allowing in only pre-sterilized air and media, and are closely monitored with sensors that monitor pH, oxygen, temperature, and nutrient. Even with these safeguards, large-scale fermentation is complex. Microbes that work well in the lab may behave unpredictably in giant industrial tanks, and contamination risks never fully disappear. Purifying proteins adds more cost and energy, especially if the microbe does not naturally secrete them. To improve outcomes, scientists are now using AI to choose the best microbes, predict gene sequences, and fine-tune expression, folding, purification, and yield. Beyond sterility, there are technical hurdles in getting microbes to make animal proteins reliably. Proteins may misfold or lack the chemical modifications they need, which can affect their properties in the final food product, for example, their ability to foam in a latte, gel in yogurt, or emulsify fat and water in cheese. Reproducing equivalent taste, texture, and digestibility is a major barrier for PF, but if overcome, the result is dairy and egg proteins that look, taste, and act like those from animals [1][7][8].
One of the most exciting aspects of PF is its potential to improve both health and safety in the foods we eat. Proteins such as cultured milk can be made without antibiotics or hormones, since microbes do not require these molecules to grow. Unlike animal products, they are naturally cholesterol-free as microbes do not produce cholesterol. Because production takes place in closed bioreactors, the risk of contamination with foodborne pathogens such as E. coli or Salmonella is much lower than in livestock farming. Microbial β-lactoglobulin (milk protein) and ovalbumin (egg protein) show amino acid profiles and structures indistinguishable to their animal versions, and their digestibility is either comparable or even better. These proteins can also be modified to remove components that trigger intolerances for specific nutritional needs. For example, scientists can produce milk proteins without lactose, since only the protein gene is inserted, not the pathway for milk sugar, or design specialized foods for people with metabolic disorders. This ability to tune protein composition is one of the strongest advantages of PF over conventional animal farming [4][9][10].
Companies like Perfect Day, The EVERY Company, and Impossible Foods are already leading the way with PF to make animal-free proteins. Perfect Day produces whey proteins, found in ice cream, protein powders, and supplements. The EVERY Company makes egg proteins that foam and bind in baking just like those from hens. Impossible Foods uses soy leghemoglobin, a protein that gives plant-based burgers their meaty taste and color. These examples show how PF can provide both the nutritional proteins people depend on and the sensory qualities they expect from animal foods. Looking ahead, some reports predict that by 2030, up to 90% of cow-derived dairy ingredients could be replaced by proteins made through PF, especially in products like supplements, powders, and processed foods that currently account for about one-third of milk use. Beyond these, companies are now exploring breast milk proteins for infant nutrition, collagen and fats to enhance the texture of plant-based meats, specialty ingredients such as milk proteins engineered without phenylalanine for people with phenylketonuria (PKU), a metabolic disorder that requires strict dietary control [1][11].
As PF moves beyond imitation and into new functions in food it also brings new questions especially around whether these proteins are safe to consume. Safety begins with choosing microbes with a long history in food and classified as GRAS. The purified proteins must go through tests such as toxin screening, allergen testing, and digestibility studies before approval, and research is continuing to see how these tests reflect long-term health and nutrition. Tests for allergenicity and toxicity are carried out, but standardized methods are still lacking, making this an area where more research is needed. Approvals and food labels also need more clarity. Since PF proteins are the molecular identical molecules to their animal counterparts, the bigger hurdle may not be safety but consumer acceptance, especially with labels that mark them as ‘genetically modified’. In the U.S., rules focus on the final protein, while in Europe regulators also look at how it was made. This means the same protein may be labeled differently in different countries, which can confuse people. To build trust, PF foods need clear safety standards, transparent labeling, and communication that helps people understand not only their potential benefits but also how they are made [3][4][7][10].
Interest in microbial protein and precision fermentation is growing across research, policy, and industry. Beyond replacing animal proteins, it also opens the door to creating entirely new proteins with tailored nutrition or specific functions. As a scientist, I’ve learned this isn’t about replacing all conventional food. It’s about opening new paths that ease pressure on animals and ecosystems. We’ve had agricultural and industrial revolutions, and now a biology-driven one shows great promise. Some of the foods we’ve grown up with are beginning to take new forms, not in taste, but in how they are made. If the food we love can be made differently, with less harm, shouldn’t we be open to that possibility?
References
[1] M. B. Nielsen, A. S. Meyer, and J. Arnau, “The Next Food Revolution Is Here: Recombinant Microbial Production of Milk and Egg Proteins by Precision Fermentation,” Annu Rev Food Sci Technol, vol. 15, no. 1, pp. 173–187, Jun. 2024, doi: 10.1146/annurev-food-072023-034256.
[2] C. L. Lumsden, J. Jägermeyr, L. Ziska, and J. Fanzo, “Critical overview of the implications of a global protein transition in the face of climate change: Key unknowns and research imperatives,” One Earth, vol. 7, no. 7, pp. 1187–1201, Jul. 2024, doi: 10.1016/j.oneear.2024.06.013.
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[5] K. R. Choi, S. Y. Jung, and S. Y. Lee, “From sustainable feedstocks to microbial foods,” Nat Microbiol, vol. 9, no. 5, pp. 1167–1175, Apr. 2024, doi: 10.1038/s41564-024-01671-4.
[6] A. Tzachor, “Novel foods for human and planetary health,” Nat Food, vol. 3, no. 4, pp. 247–248, Apr. 2022, doi: 10.1038/s43016-022-00492-0.
[7] J. H. Dupuis, “Introduction to fermentation technologies and techniques,” in Cellular Agriculture, Elsevier, 2024, pp. 295–310. doi: 10.1016/B978-0-443-18767-4.00034-2.
[8] N. S. Terefe, “Recent developments in fermentation technology: toward the next revolution in food production,” in Food Engineering Innovations Across the Food Supply Chain, Elsevier, 2022, pp. 89–106. doi: 10.1016/B978-0-12-821292-9.00026-1.
[9] A. Choręziak, D. Rosiejka, J. Michałowska, and P. Bogdański, “Nutritional Quality, Safety and Environmental Benefits of Alternative Protein Sources—An Overview,” Nutrients, vol. 17, no. 7, p. 1148, Mar. 2025, doi: 10.3390/nu17071148.
[10] A. A. Pereira, M. A. Yaverino-Gutierrez, M. C. Monteiro, B. A. Souza, R. K. Bachheti, and A. K. Chandel, “Precision fermentation in the realm of microbial protein production: State-of-the-art and future insights,” Food Research International, vol. 200, p. 115527, Jan. 2025, doi: 10.1016/j.foodres.2024.115527.
[11] L. J. Jahn, V. M. Rekdal, and M. O. A. Sommer, “Microbial foods for improving human and planetary health,” Cell, vol. 186, no. 3, pp. 469–478, Feb. 2023, doi: 10.1016/j.cell.2022.12.002.
Cover image- created on ChatGPT
Author:
Vandana Mishra is a structural biologist and biochemist who studies the structure and function of proteins in health and disease. She earned her Ph.D. from IIT Bombay, India, and completed her postdoctoral research at the NIH. Her work spans crystallography, cryo-EM, cryo-ET, and biophysics, with a focus on therapeutic discovery. She is currently a research volunteer at Johns Hopkins University and a writer and social media manager at MedNess.
She enjoys communicating science through writing and outreach that connect research with everyday life and showing how science shapes the world around us. Outside the lab, she likes hiking, photography, vegan food science, poetry, and science humor.
This article was written as part of Club SciWri’s first Science Writing Workshop, an initiative aimed at nurturing new voices in science communication and helping participants explore how to make complex ideas accessible to wider audiences.
Workshop conducted by Saurja Dasgupta, Sumbul Jawed Khan, Ananya Sen, Rohini Subrahmanyam, and Roopsha Sengupta
