Methanotrophy Goes Commercial: Challenges, Opportunities, and Brief History

Abstract

Methane is an advantaged feedstock due to its high energy density and widespread abundance. Prices of methane are at historic lows due to modern natural gas extraction techniques and advances in biogas generation by anaerobic digestion. The availability of genetically tractable methanotrophs that can grow readily in industrial settings and new developments in gas fermentor design that address obstacles like gas mass transfer and removal of metabolic by-products combine to present a bright future for commercial methane-based fermentation. Although not without challenges, this technology offers a unique opportunity to transform the way consumer goods—from biopolymers to biofuels—are produced. Large-scale methane fermentation has already been validated for the production of single-cell protein used in animal feed, a process that addresses the critical issue of food security in the near future without compromising the human food chain and with minimal use of land and water. As a bonus, on-purpose methane fixation can have a significant impact in reducing the accumulation of this powerful greenhouse gas in the atmosphere. In this chapter we will present an overview of the opportunities and challenges, as well as a brief history, of commercial methane fermentation.