Deep Branch, a biotechnology startup in the UK, has created an intriguing new form of single cell protein called Proton. Proton is made from carbon dioxide gas that has been fermented by microbes. Hydrogen is used as an energy source in the process and ammonia is used as a nitrogen source. This new single cell protein will be used as a protein supplement in animal feed/livestock feed. Proton has an extremely high protein content, around 70%, compared to its competitors, soybean meal and fishmeal, which have 45% and 65% respectively. Although the quality of proton compared to these feeds is unknown, the carbon footprint of its production is, according to the founders of Deep Branch, 90% less than that of traditional protein harvesting methods for livestock feed. For instance, the harvesting of soybean is a lead causer of deforestation and requires land usage/lots of energy. Meanwhile the production of fishmeal can lead to overfishing and depletion of certain fish populations. There re fish that are specifically farmed to produce fishmeal, which, like soybean meal, is increasingly fed to poultry, swine, and used in aquaculture. Proton's sustainability comes from the fact that it is recycling carbon dioxide emissions and putting them back into animal feed. Currently, Proton is using carbon dioxide waste from the Drax bioenergy plant in the UK. This recycling of carbon dioxide is efficient because carbon dioxide and other greenhouse gases are the lead cause of global warming, which leads to climate change, which is a harmful phenomenon. Proton is fairly new, as Deep Branch was established in 2018, but it is on the rise, with funding coming in for the company from various sources. The price point, the quantity required compared to another traditional source of protein, and the quality of the product are currently unknown. However, Proton is an innovative, exciting prospect for the future of sustainable biotech and clean agriculture.