4. lisbeth olsson biochemical conversion 2017-03-28 · 2017. 4. 12. · [email protected]...

INDUSTRIAL BIOTECHNOLOGY

Lisbeth OlssonIndustrial biotechnology, Chalmers


Industrial Biotechnology Department of Biology and Biological Engineering

Chalmers University of Technology Göteborg, Sweden

[email protected]

Bioethanol and bioproducts for the bio‐based economy – development of robust

cell factories and robust processes

Maurizio Bettiga, Carl Johan Franzén, Johan Larsbrink, Lisbeth Olsson


Enzymatichydrolysis

Product

Fermentation

Enzymediscovery and design

Propagation Cell factory

Fermentable sugar stream

Raw material stream containing mono‐, oligo and polysaccharides, lignin, inhibitors (furans, weak acids and phenolics)

Process integration and optimization

Biochemical conversion of biomass


Robust microorganisms and processes ?• Microbial processes receive more and more industrial importance in line with bio‐based economy solutions

• Understanding and ability to improve robustness increase the industrial potential for microbial conversion

• Developing robust process allow for maximum utilization of the potential of the production host

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Robustness, the ability to maintain performance in the face of perturbations and uncertainty, is a long‐recognized key

property of living systemsStelling J et al. (2004) Cell 118:675‐685


Enzymes

• Biological catalysts• Act on specific chemical bonds

• Has a certain size


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Process robustness

Koppram, R., E. Tomas‐Pejo, Elia, C. Xiros, L. Olsson (2014) Trends in Biotechnology, 32, 46‐53


Multi‐feed SSCF – Process design

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• Fed‐batch SSCF with feeds of solids, yeast, (and enzymes)

• Integrated yeast propagation and adaptation

Koppram and Olsson, Biotechnol Biofuels 2014, 7:54, Wang et al., Bioresource Technol 2014, 172:303‐311Wang et al Biotechnol Biofuels 2016, 9:88

SSCF

Liquidfraction

Cell Feed

SolidsFeed

Continuous yeast cultivation

Pretreated wheat straw

Enzymes

Strategies for more robust processes


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Ethanol yield: 56%Ethanol yield: 13%

20 % WIS SpruceBatch SSF Multi‐feed SSF

Koppram and Olsson, Biotechnol Biofuels 2014, 7:54

Multi‐feed SSF improves mixing and reduces inhibition of hydrolysis and fermentation



30

40

50

60

70

Max

imal

EtO

H ti

ter

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> 20% WIS

Model‐based feed of solids

Flocculating cells

New material, more hydrolysate in propagation, temperature decrease

Quicker feed of solids, more hydrolysate in SSF (strain 1 and 2)

15% WIS A

B

C

D

E

F

Initial enzyme, cell feed

Enzyme feed, Initial cell

Multifeed SSF allowsfor improved highgravityfermentations – highcell viability is a key



From sugar to polymers using cell factories

Microbial conversion –development of microbial catalyst

Sugar rich biorefinerystreams

Polymeric building Polymeric building blocks; 3‐hydroxy propionic acid, lactic aid, adipicacids

Using strain engineering we develop the microorganism to:• Produce the targetted product at high yield and productivity• Being robust to industrially prevailing conditions


11Inhibitors influence cellular functions in numerous ways

Cellular robustness


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Reduce uptakeEnhance excretion

Reduce damage

Enhance repair

Enhance conversion (detoxification)

Strain improvement strategies for increased cellular robustness should enable functions including

Cellular robustness


0

2

4

6

8

10

12

14

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0 5 10 15 20 25 30

8 μmol glutathione/(g DCW)

Concen

tration (g/l)

Time (h)

ETHANOL‐CONTROL STRAIN

ETHANOL‐GSH STRAIN

Ask et al. (2013) Microbial Cell Factories 12:8713

Fermentation performance of glutathione modulated strains

12 μmol glutathione/(g DCW)

Cellular robustnessReduce damage and increase repair


Robust processes and cellular robustness in a biorefinery perspective

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Thanks to ….Industrial Biotechnology group members

Our research within cellular robustness process robustness was funded by

… and collaborators

4. lisbeth olsson biochemical conversion 2017-03-28 · 2017. 4. 12. · [email protected]...

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