Energy Biosciences Institute

Department of Plant and Microbial Biology

UC Berkeley

Plant Biotechnology for Biofuels

Princeton University, October 14, 2013

Markus Pauly

CO2-concentration in the atmosphere!

Today!800,000! 600,000! 400,000! 200,000!

ppm!

185 ppm (Ice ages)!

280 ppm (Preindustrial)!

Scripps Institute of Oceanography; National Climatic Data Center !

6 ppm!

Annual Cycle!

Jan Apr Jul Oct Jan!

0 500 1000 1500 Today!

11 May, 2013: 400 ppm!

© Markus Pauly

Chloroplast

Hexose-P

Carbon fixation in plants

Triose-P

Triose-P

Chloroplast

Sucrose (transport)

Starch (storage)

Glycolysis (energy)

Cell Wall Polymers (structure)

CO2

H2O

CO2

H2O

© Markus Pauly

Plant cell walls and Carbon Cycle

Assimilated CO2 Plant Biomass (land, worldwide) Cell walls (land, worldwide)

55 x109 t / a

170 – 200 x 109 t / a 120 – 170 x 109 t / a

Annual global production of chemicals 2010 1.2 x 109 t (without pharmaceuticals)

BASF report 2010 – Trends in the chemical industry

Field et al., 1998; Porter and Vilar, 1997; Pauly and Keegstra 2008

► Cell walls represent the dominant biological carbon sequestration system

© Markus Pauly

Cellulose Hemicellulose Pectin xyloglucan galactomannan arabinoxylan

Homogalacturonan

Ca2+-crosslinked

non-methylesterified methylesterified

Rhamnogalacturonan

RG II (boron-diester)

RG I (galactan) (arabinan)

The Plant Cell Wall © Markus Pauly

Cellulose Hemicellulose Polyphenols (Lignin)

The mature Plant Cell Wall © Markus Pauly

Redwoods: up to 379 feet high, up to 2200 y old

- structural integrity of cell/ tissue/ plant - cell shape/ plant morphology - cell adhesion - barrier (mechanical/ path. defense)

Buchanan, 1999

- dynamic entity of the cell - cell expansion

Keith Roberts

- reposit for signaling molecules - pathogen attack

Function of plant cell walls © Markus Pauly

► plant species ► plant tissue ► plant cell

Courtesy of Paul Knox, Univeristy of Leeds

The Plant Cell Wall: Diversity © Markus Pauly

Plant tissue (Lignocellulosics)

Dissolution in organic solvent Ball milling 2D-NMR

spectroscopy

10 mg (dry)

750 µl : 10 µl DMSO-d6/[Emim]OAc-d14

Assessment of plant cell wall structural diversity: Whole lignocellulosic 2D-NMR

Kun Cheng

© Markus Pauly

Kun Cheng

Whole lignocellulosic 2D-NMR 1H-13C HSQC

© Markus Pauly

Whole lignocellulosic 2D-NMR

Anomeric polysaccharides

© Markus Pauly

Whole lignocellulosic 2D-NMR Aromatic

Lignin

© Markus Pauly

Whole lignocellulosic 2D-NMR

Aliphatic Lignin linkages

© Markus Pauly

Whole lignocellulosic 2D-NMR

Molar percentage (Miscanthus)

Glc Xyl Ara Man GlcA Ac-xylan

63.0 32.0 3.0 2.0

>1.2 53.0

+/- 3 +/- 1 +/- 0.5 +/- 0.5 +/- 2

Guaiacyl (G) Syringyl (S) P-hydroxyphenyl (H)

54.0 40.0 5.0

+/- 1 +/- 1 +/- 0.5

S/G ratio >1.8

Aryl-ether (A) Phenylcoumaran (B) Resinol (C) Dibenzodioxacin (D)

68.0 1.0 7.0

24.0

+/- 3 +/- 0.5 +/- 1

Cheng, Sorek, Zimmermann, Wemmer, Pauly (2013) Analytical chemistry

© Markus Pauly

Forestry resources

Pine Poplar Willow Maple

Arabidopsis

Switchgrass Miscanthus

Maize Rice Sugarcane Sorghum

Eucalyptus

Model plant

Energy Grass

Agriculture residues

„Structural Space“ of lignocellulosics

Plant species

© Markus Pauly

Lignocellulosic structural diversity

Sugarcane bagasse

Cordgrass straw

Miscanthus straw

Agave americana

Pine wood

Eucalyptus wood

Cellulose

Non- Cell Lignin

β-O-4’ β-5’

β-β’

5-5’ β-O-4’

S G

H

pCa

FA

Ara

GlcA

Sorghum Maize leaf

Maize cob

Poplar wood

Willow wood

Agave fourcroydes

Agave tequilina

© Markus Pauly

Principal component clustering

„Structural Space“ of lignocellulosics

(35%)

(17%

)

(35%)

Miscanthus Sugarcane

Sorghum

Switchgrass

Pine

Maize

Eucalyptus Arabidopsis

Willow Maple

Poplar

Plant species ► Grasses ≠ Wood (Hardwood ≠ Softwood)

Kun Cheng

© Markus Pauly

oil

refinery

gasoline

vehicle

CO2

plants

biorefinery

biofuel

vehicle

CO2

► Plants capture energy from the sun ► Plants convert energy into durable chemicals ► Plants sequester CO2 from the atmosphere

Alternative to fossil fuels: Plant biomass © Markus Pauly

Lignocellulosics as renewable resource

► Cell walls (lignocellulosics) are non-food components

Dominant biological carbon sequestration system ► Lignocellulosics are highly abundant

► The conversion of lignocellulosics is energy and cost- intensive

© Markus Pauly

Chemical

Biological

Biomass to Biofuels

Conversion steps

Transesterification

Fuel

Biodiesel

Ethanol Butanol

Fermenta- tion Enzymatic

hydrolysis

Biomass Vegetable

Oil

Sugar

Starch

Biological

Methane Anaerobic gasification

Thermochemical

Hydrocarbons

Pyrolysis

Syngas production

Pre- treat- ment

Catalytic Conversion

Fischer Tropsch process Ligno-

cellulosics

© Markus Pauly

► Increase plant biomass/ ha ► Choice of crops ► Increase resource efficiency (water, fertilizer) ► Delayed flowering (energy maize: www.kws.com)

Van Holme, 2007

► Increase the yield of fermentable sugars ► Create a more open wall architecture (reduce, alter lignin) ► Reduce process inhibitors ► Increase cellulose (amorphous), hemicelluloses (hexoses)

Challenges: Plant biology – 2nd Gen Biofuels © Markus Pauly

Pauly lab

Acknowledgements

Lifeng Liu Jonathan Paulitz Guangyan Xiong Amancio Souza Nasim Mansoori Alex Schultink Julia Schulbert Dan Naylor

Sarah Hake, USDA Albany Patrick Brown, UIUC ISU transformation facility

Collaborators: