ABSTRACT
Macroalgae contain unique components sought after in various industries, including food, medical and agricultural. Given their low lignin and high carbohydrate content, brown macroalgae have recently been identified as a potential substrate for third-generation biofuel production. Different strategies and processes are required to utilise macroalgae and exploit their valuable compounds efficiently, as the extraction thereof is restricted by its complex carbohydrate composition. Specific enzymes are required to break down the main carbohydrates, namely laminarinase and mannitol dehydrogenase, to hydrolyse laminarin and mannitol, and alginate lyase to depolymerise alginate. These enzymes occur naturally in various microorganisms, but they must be produced at high levels to ensure a sufficient supply for commercial applications. This can be achieved with the recombinant expression of the relevant genes in a suitable microbial host. In this chapter, the different carbohydrates in macroalgae and the enzymes required to release valuable constituents are discussed. Special attention is given to enzymes that release fermentable sugars from brown macroalgae, as well as different microbial platforms available for biofuel production.
