Patent ID: 8093456

Claim:
A method for converting lignocellulose of plant material from a cover crop with low amounts of lignin to fermentable sugars comprising: (a) providing a transgenic monocot plant selected from the group consisting of rice, wheat, barley, oat, triticale, and rye, the transgenic monocot plant being a low-lignin cover crop which includes (i) at least one DNA encoding a cellulase and hemicellulase which is operably linked to a nucleotide sequence encoding a signal peptide wherein the signal peptide directs the cellulase to an organelle of the transgenic plant and (ii) at least one DNA encoding a ligninase which is operably linked to a nucleotide sequence encoding a signal peptide wherein the signal peptide directs the ligninase to the organelle of the transgenic plant; (b) growing the transgenic plant for a time sufficient for the transgenic plant to accumulate a sufficient amount of the cellulase and hemicellulase and the ligninase in the sub-cellular compartments of the transgenic plant; (c) harvesting the transgenic plant which has accumulated the cellulase, hemicellulase and ligninase in the sub-cellular compartments of the transgenic plant; (d) grinding the transgenic plant for a time sufficient to produce the plant material wherein the cellulase, hemicellulase and ligninase produced by the transgenic plant are released from organelle and cell wall areas of the transgenic plant; (e) incubating the plant material for a time sufficient for the cellulase, hemicellulase and ligninase in the plant material to produce the fermentable sugars and lignin deconstructed by the ligninase from the lignocellulose in the plant material; and (f) extracting the fermentable sugars produced from the cellulose and hemicelluloses by the cellulase and hemicellulase from the plant material.