12 LIGNIN BIOSYNTHESIS AND LIGNIN MANIPULATION

摘要

1 INTRODUCTION Lignin is critical to normal plant health and development but is sometimes less useful from an industrial perspective where it is often seen as a troublesome component of plant biomass. For the past 20 years, research has explored the opportunities for manipulating lignin by genetic engineering to improve biomass for industrial or agricultural processes. Initial work focussed on improving wood for papermaking by reducing lignin content, or making it easier to extract during pulping, so that the costs and environmental impact of isolating relatively clean cellulose fibres were reduced. The prospect of making forages more digestible by manipulating lignin to enable greater release of the energy stored in wall carbohydrates, has also been explored. Today, there is a major push towards manipulating lignin to allow more efficient biofuel production from plant biomass by allowing enzymes easier access to the polysaccharide components of cell walls that can be used as substrates for fermentation into fuels.