Biocatalytic and Fermentative Production of α,ω-Bifunctional Polymer Precursors

The worldwide market for biomaterials is projected to grow by a two-digit number annually over the next decade, a trend evoked predominantly by increasing customer awareness as well as rising demand for sustainable materials. As a consequence, research activities aiming at the development of bioprocesses for monomer production have also been boosted. This process is at last beginning to bear fruit, as commercialization of molecules such as succinic acid and 1,4-butanediol is taking place just now. This review summarizes the recent progress made in biocatalytic and fermentative production of medium- and long-chain alpha,omega-bifunctional monomers suitable as building blocks for polyamide and polyester synthesis. Both linear molecules, such as omega-hydroxy and omega-amino fatty acids, alpha,omega-diamines, -diols, and -dicarboxylic acids, as well as cyclic molecules, e.g. lactones, lactams, and furanes are covered. It is demonstrated that developmental stages differ significantly for the individual molecule classes. Apart from the already commercialized bioprocess technologies for production of long-chain dicarboxylic acids, state-of-the-art is currently most advanced for synthesis of omega-hydroxy fatty acids from fatty acids or their methyl esters. In contrast, synthesis of biobased alpha,omega-diols and the corresponding diamines from low-cost raw materials has not yet passed the proof-of-concept stage.