3 - Genetically engineered lignocellulosic feedstocks for enhanced biofuel yields

Abstract

The sustainability of any bio-based industry rests on a consistent supply of large volumes of biomass. However, efficient conversion of the feedstocks to fermentable sugars is limited by cell wall recalcitrance to degradation and fermentation processes. Modern plant breeding technologies have significantly enhanced bioenergy production in several crops. The genetic modification strategies have targeted alteration of the structure of enzymes and overexpression or silencing of genes involved in different pathways to improve feedstock yield and quality in the various plants. Genetic engineering using recombinant DNA technology has played a significant role by introducing a more comprehensive range of traits unavailable through conventional breeding, making direct changes in the plants or organisms. Recently, clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, another engineering technology, allows researchers to change DNA sequences and gene functions without isolating the gene, engineer it in vitro put it back into the host cell as is done in conventional genetic engineering. This chapter focuses on the progress in applying genetic engineering to produce transgenic biofuel feedstocks. It highlights different strategies employed, limiting the discussion mainly to lignocellulosic biofuels, challenges faced, and future perspectives of genetic engineering technology for sustainable biofuel production.