Proteins are flexible biological polymers with a broad array of applications, including catalysis, medicines, fabrics, membranes, sensors, fibers, etc. As we search for sustainable replacements of fossil-derived chemicals and polymers, natural or designed proteins and protein-based materials top the list of the most advanced alternatives. A few successful developments, such as microbial milk, synthetic collagen, and silks, are already entering the market, but it is clear that additional advances are needed. The implementation of proteins as alternative materials requires innovations in the development of novel biological platforms that can deliver proteins at scale and marketable prices. This chapter explores the potential of microbial systems that utilize reduced single-carbon compounds, such as methane and methanol, for commercial-scale production of proteins. We summarize available data, primarily rooted in the biotechnology for single-cell protein (SCP) production, and explore the potential of methanotrophic organisms as a nexus platform for the industrial synthesis of enzymes, food suppliments, pharmaceuticals and protein-based materials. .