Plant Biotechnology Journal (2014) 12, pp. 1153
doi: 10.1111/pbi.12293
Editorial The future role of biotechnology to enable next-generation biofuel production The first generation of liquid biofuels for transportation has been extraordinarily successful. Ethanol from maize grain, sugarcane and sugar beet as well as biodiesel from vegetable oil offset a significant portion of petroleum use each year. Furthermore, today’s success has happened largely without the involvement of plant biotechnology. Of course, the food/feed fuel dilemma and environmental issues of first-generation bioenergy feedstocks lead us to seek new solutions. Why then will plant biotechnology be useful, perhaps absolutely necessary, to produce next-generation biofuels, and why are advanced biofuels even needed? The short answer to the last part of the question is that maximum production of ethanol and transesterified lipids has been reached, at least in the USA and several other countries. The next generation of biofuels will come from lignocellulosic sources, algae and various other plant feedstocks for drop-in fuels. Biotechnology will likely be required for sustainable production of many of these next-generation dedicated bioenergy feedstocks because of recalcitrance of conversion, low efficiency and a paucity of endogenous metabolic pathways needed to produce sufficient amounts of drop-in fuel compounds. That is to say, the easy problems have been solved by relatively simple methods. The ‘wicked’ problem of next-generation bioenergy production, a multifactorial problem, will require innovation from start to finish for success. Plant biotechnology will certainly play important roles to deliver effective feedstock. In this Focus Issue on Biofuels, five articles explore the use of plant biotechnology for the production of next-generation biofuels. The extreme difficulty of digesting plant cell walls for
biofuel production, the recalcitrance problem, is chief amongst known impediments to lignocellulosic feedstock utilization. Lignin is known to occlude hydrolysis of cellulose. In this issue, Liu et al. and Poovaiah et al. review the literature on lignin biosynthesis and strategies alter lignin polymer composition and decrease its production. Lignin manipulation is probably the most advanced biotechnological strategy we have in our arsenal in creating better feedstocks; yet, the first studies on field deployment of such feedstocks were only recently published. Li et al. further develop the theme of plant biotechnology for lignocellulosic crops by including hemicellulose and other cell wall targets. Furthermore, Li et al. also review the use of in planta synthesis of cell wall-degrading enzymes. Farrar et al. expand our field of view even farther by analysing current progress in beneficial plant–microbe interactions for improved plant growth. Synthetic biology strategies are introduced here and then further developed by Kalluri et al. Systems and synthetic biology will likely go hand in hand to not only finetune current feedstocks, but to also potentially produce truly novel feedstocks and biofuel products. Taken together, these articles peer into the future of using plant biotechnology and synthetic biology strategies to solve complex biofuel-related problems.
ª 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd
C. Neal Stewart, Jr e-mail [email protected]
1153
doi: 10.1111/pbi.12293
Editorial The future role of biotechnology to enable next-generation biofuel production The first generation of liquid biofuels for transportation has been extraordinarily successful. Ethanol from maize grain, sugarcane and sugar beet as well as biodiesel from vegetable oil offset a significant portion of petroleum use each year. Furthermore, today’s success has happened largely without the involvement of plant biotechnology. Of course, the food/feed fuel dilemma and environmental issues of first-generation bioenergy feedstocks lead us to seek new solutions. Why then will plant biotechnology be useful, perhaps absolutely necessary, to produce next-generation biofuels, and why are advanced biofuels even needed? The short answer to the last part of the question is that maximum production of ethanol and transesterified lipids has been reached, at least in the USA and several other countries. The next generation of biofuels will come from lignocellulosic sources, algae and various other plant feedstocks for drop-in fuels. Biotechnology will likely be required for sustainable production of many of these next-generation dedicated bioenergy feedstocks because of recalcitrance of conversion, low efficiency and a paucity of endogenous metabolic pathways needed to produce sufficient amounts of drop-in fuel compounds. That is to say, the easy problems have been solved by relatively simple methods. The ‘wicked’ problem of next-generation bioenergy production, a multifactorial problem, will require innovation from start to finish for success. Plant biotechnology will certainly play important roles to deliver effective feedstock. In this Focus Issue on Biofuels, five articles explore the use of plant biotechnology for the production of next-generation biofuels. The extreme difficulty of digesting plant cell walls for
biofuel production, the recalcitrance problem, is chief amongst known impediments to lignocellulosic feedstock utilization. Lignin is known to occlude hydrolysis of cellulose. In this issue, Liu et al. and Poovaiah et al. review the literature on lignin biosynthesis and strategies alter lignin polymer composition and decrease its production. Lignin manipulation is probably the most advanced biotechnological strategy we have in our arsenal in creating better feedstocks; yet, the first studies on field deployment of such feedstocks were only recently published. Li et al. further develop the theme of plant biotechnology for lignocellulosic crops by including hemicellulose and other cell wall targets. Furthermore, Li et al. also review the use of in planta synthesis of cell wall-degrading enzymes. Farrar et al. expand our field of view even farther by analysing current progress in beneficial plant–microbe interactions for improved plant growth. Synthetic biology strategies are introduced here and then further developed by Kalluri et al. Systems and synthetic biology will likely go hand in hand to not only finetune current feedstocks, but to also potentially produce truly novel feedstocks and biofuel products. Taken together, these articles peer into the future of using plant biotechnology and synthetic biology strategies to solve complex biofuel-related problems.
ª 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd
C. Neal Stewart, Jr e-mail [email protected]
1153
