Use of plants with reduced levels of de-esterified homogalacturonan in the cell wall or portions thereof for improving the saccharification of plant biomasses

• US 20100170008A1
• Filed: 12/29/2009
• Published: 07/01/2010
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Universita' Degli Studi Di Roma La Sapienza (Repubblica Italiana)
• Original Assignee: Universita' Degli Studi Di Roma La Sapienza (Repubblica Italiana)
• Inventors: SALVI, Giovanni, FERRARI, Simone, LIONETTI, Vincenzo, CERVONE, Felice, PONTIGGIA, Daniela, BELLINCAMPI, Daniela, FRANCOCCI, Fedra, DE LORENZO, Giulia
• Granted Patent: US 8,637,734 B2
• Time in Patent Office: Days
• US Class Current: 800/295
• CPC Class Codes: C12N 15/8246 Non-starch polysaccharides, e.g. cellulose, fructans, levans

Abstract

The present invention relates to expression in plants of pectinolytic enzymes and of pectin methylesterase inhibitors for increasing the degradability of plant tissues through enzymatic digestion, thus improving saccharification efficiency.

Claims

1. Use of plants having a reduced content of de-esterified homogalacturonan (HGA) in the pectins of said plants cell walls and a reduced resistance to saccharification with respect to control plants in a saccharification process of plant biomasses.

2. Use of plants according to claim 1 wherein said plants are obtained by genetic transformation with a gene encoding an agent able to reduce the content of de-estherified HGA in the pectins.

3. Use of plants according to claim 2 wherein said agent is a polygalacturonase.

4. Use according to claim 3 wherein the gene encoding a polygalacturonase is from Aspergillus niger.

5. Use according to claim 3 wherein the gene encoding a polygalacturonase is modified to produce an enzyme having a reduced specific activity.

6. Use according to claim 5 wherein the gene encodes a polygalacturonase having a reduced specific activity and having the amino acid sequence of SEQ ID No. 2.

7. Use according to claim 5 wherein the gene encoding a polygalacturonase having a reduced specific activity has the nucleotide sequence of SEQ ID No. 1.

8. Use of plants according to claim 1 wherein said plants are obtained by transformation with a gene encoding an inhibitor of pectin methyl esterases or with a gene encoding a pectate lyase or by selecting natural or mutagenesis induced variants.

9. Use of plants according to claim 8 wherein the gene encoding an inhibitor of pectin methyl esterases is of plant origin.

10. Use of plants according to claim 9 wherein the gene encodes an inhibitor of pectin methyl esterases having the amino acid sequence of SEQ ID No. 4.

11. Use of plants according to claim 10 wherein the gene encoding an inhibitor of pectin methyl esterases has the nucleotide sequence of SEQ ID No. 3.

12. Use of plants according to claim 8 wherein the gene encoding a pectate lyase is of bacterial origin.

13. Use of plants according to claim 12 wherein the gene encodes a pectate lyase having the amino acid sequence of SEQ ID No. 6.

14. Use of plants according to claim 12 wherein the gene encoding a pectate lyase has the nucleotide sequence of SEQ ID No. 5.