Unravelling mycoprotein bioproduction by Neurospora crassa towards development of a vegan steak.

The rising world population and the associated demand for meat are putting increasing pressure on the meat industry. As a result, the meat industry now demands 40% of the global yield of cereals for feed. These cereals are increasingly difficult to grow due to the climate change, also caused by emissions from the meat industry. The share of greenhouse gases from livestock farming is estimated at an average of 14.5% of global emissions. A suitable alternative with a similar nutritional value is required. The use of meat substitutes based on mycoprotein offers a good alternative to meat products and vegetable-based meat substitutes. For example, less than 800L of water is consumed for the production of 1kg of mycoprotein compared to the 15,000L of water needed for 1kg of beef. In addition, the emissions resulting from the production of mycoprotein are significantly lower than those from beef. The overall composition of mycoproteins, including the amino acid composition, is very similar to that of red meat. During the doctoral research, the focus will be on the study of the microbial production of a meat alternative specifically intended to replace red meat, more specifically steak. For this purpose, the filamentous fungus Neurospora crassa will be used for the production of mycoproteins by means of fermentation in liquid medium. N. crassa naturally produces carotenoid pigments including β- and γ-carotene which will be beneficial in obtaining the desired color for the meat substitute. When looking at the structure, a fibrous and meaty structure is preferred. The length of the hyphae contributes to obtaining the desired meat-like structure. N. crassa hyphae can grow to an average length of 930µm under the right conditions. All these characteristics make N. crassa the ideal candidate for developing a vegan steak as an innovative meat alternative. The aim of this PhD research is to obtain a meat alternative to beef based on mycoprotein derived from Neurospora crassa. The structure, color and texture of the meat alternative should be as similar as possible to that of a steak. For this purpose, various aspects of fermentation will be investigated and optimized such as the medium used, the necessary carbon and nitrogen source and the process parameters of fermentation (including temperature, pH, aeration and agitation). All of this will be done with a view to producing quality mycoprotein and a cost-efficient production process. Furthermore, the necessary processing of the mycoprotein into a basic meat substitute will be mapped. Finally, a full characterization of the obtained product will be performed to show the nutritional value of the obtained meat substitute. The obtained results create an opportunity for the use of Neurospora crassa in future research and within industrial applications.