Consolidated pretreatment and hydrolysis of plant biomass expressing cell wall degrading enzymes
Methods for consolidated pretreatment and hydrolysis of genetically engineered plants expressing cell wall degrading enzymes are provided. Expression cassettes and vectors for making transgenic plants are described. Plants engineered to express one or more cell wall degrading enzymes using expression cassettes and vectors of the invention are also provided.
1. An engineered plant comprising a first polynucleotide sequence, a second polynucleotide sequence, and a third polynucleotide sequence, wherein the first polynucleotide sequence encodes a xylanase comprising an amino acid sequence of SEQ ID NO: 6, the second polynucleotide sequence encodes an endoglucanase comprising an amino acid sequence of SEQ ID NO: 4, and the third polynucleotide sequence encodes a cellobiohydrolase comprising an amino acid sequence of SEQ ID NO: 10 or 12.
2. The engineered plant of claim 1 , wherein at least one of the first polynucleotide sequence, the second polynucleotide sequence, or the third polynucleotide sequence further comprises a targeting polynucleotide sequence encoding a targeting peptide selected from the group consisting of: an amyloplast targeting signal, a cell wall targeting peptide, a vacuole targeting peptide, a mitochondrial targeting peptide, a cytosol localization signal, a chloroplast targeting signal, and a nuclear targeting peptide.
3. The engineered plant of claim 2 , wherein the targeting polynucleotide sequence encodes a targeting sequence selected from the group consisting of: SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 22, SEQ ID NO: 23, and SEQ ID NO: 24.
4. The engineered plant of claim 1 , wherein the engineered plant is selected from the group consisting of: corn, sugar cane, sugar beet, sorghum, switchgrass, miscanthus, eucalyptus, willow and poplar.
5. The engineered plant of claim 1 , wherein the engineered plant produces more xylose under hydrolysis condition in the absence of exogenous enzymes compared to a non-engineered plant of the same genetic background lacking a xylanase, an endoglucanase and a cellobiohydrolase.
6. The engineered plant of claim 1 , wherein the engineered plant produces more glucose under hydrolysis condition in the absence of exogenous enzymes compared to a non-engineered plant of the same genetic background lacking a xylanase, an endoglucanase and a cellobiohydrolase.
7. The engineered plant of claim 1 , wherein the engineered plant produces at least 10% more xylose under hydrolysis condition in the absence of exogenous enzymes compared to a non-engineered plant of the same genetic background lacking a xylanase, an endoglucanase and a cellobiohydrolase.
8. The engineered plant of claim 1 , wherein the engineered plant produces at least 10% more glucose under hydrolysis condition in the absence of exogenous enzymes compared to a non-engineered plant of the same genetic background lacking a xylanase, an endoglucanase and a cellobiohydrolase.