Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effect of structural properties of lignin isolated from different sources on its efficiency to serve as electron donor of fungal Lytic Polysaccharide Monooxygenases
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.ORCID iD: 0000-0003-1336-2396
National Technical University of Athens.
National Technical University of Athens.
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.ORCID iD: 0000-0003-0078-5904
Show others and affiliations
2018 (English)In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834Article in journal (Refereed) Submitted
Place, publisher, year, edition, pages
BMC , 2018.
National Category
Bioenergy Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
URN: urn:nbn:se:ltu:diva-70690OAI: oai:DiVA.org:ltu-70690DiVA, id: diva2:1243428
Available from: 2018-08-31 Created: 2018-08-31 Last updated: 2018-08-31
In thesis
1. Depolymerization of Lignocellulose by Lytic Polysaccharide MonoOxygenases
Open this publication in new window or tab >>Depolymerization of Lignocellulose by Lytic Polysaccharide MonoOxygenases
2018 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Lignocellulose biomass is considered as one of the most potential and sustainable sources for the production of value-added chemicals and fuels while replacing the traditional petroleum resources. In a biorefinery, by employing biochemical conversion processes,cellulose present in the biomass is broken down into monomeric sugars which can belater converted into fuels or chemicals. This process is done with the help of different cellulose digesting enzymes (cellulases), isolated from natural cellulolytic organisms suchas saprophytic fungi.

Lytic polysaccharide monooxygenases (LPMOs) are considered as one of the vital classesof enzymes in the bio-conversion of lignocellulose. They are copper active enzymes present naturally in cellulose degrading fungi. Unlike the traditional cellulases, they havea unique way of breaking cellulose using molecular oxygen or hydrogen peroxide as cosubstratein the presence of a reducing agent. Their ability to enhance the action of other cellulases in depolymerizing the cellulose, make them an integral part of today’s commercial cellulase cocktails.

This thesis comprises the study about the action of lytic polysaccharide monooxygenaseson various cellulose substrates, both model and natural. The first part of the thesis focuses on the ability of an LPMO (MtLPMO9) and a traditional cellulase (MtEG5A), to act insynergism. The evaluation was done based on the release of oxidized and non-oxidized sugars and also on the ability to liquefy the substrates. It was observed that together, these two enzymes resulted in enhanced release of oxidized and non-oxidized sugars. Both were able to reduce viscosity of the substrates but no further synergistic effect was observed when added together.

The second part focuses on the ability of LPMOs to accept electrons from lignins for their action of breaking cellulose chains. Three LPMOs, MtLPMO9, PcLPMO9D and NcLPMO9C, lignins from agricultural and forest biomass pretreated by various pretreatment methods were selected. It was demonstrated that lignins, both in isolatedand substrate bound form were able to act indirectly as reducing agents, by releasingsoluble low-molecular-weight molecules that act as mediators between enzyme and bulklignins. The structural and compositional properties of lignins also affected their ability toact as electron donors. In addition, the effect of biomass pretreatment methods on the lignin properties was also studied. The lignins from acid catalyzed organosolv pretreatment were found as the best candidates in supplying electrons to the enzymes.Interestingly, NcLPMO9C was not able to utilize lignins as electron donors requiring further investigation on their mechanism both in vivo and in vitro.

Place, publisher, year, edition, pages
Luleå: Luleå University of Technology, 2018
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
National Category
Bioenergy Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-70406 (URN)978-91-7790-186-0 (ISBN)978-91-7790-187-7 (ISBN)
Presentation
2018-09-05, F341, Luleå University of Technology, Luleå, 13:30 (English)
Opponent
Supervisors
Available from: 2018-08-16 Created: 2018-08-15 Last updated: 2018-08-31Bibliographically approved

Open Access in DiVA

No full text in DiVA

Authority records BETA

Muraleedharan, Madhu NairTopakas, EvangelosRova, UlrikaChristakopoulos, PaulKarnaouri, Anthi C.

Search in DiVA

By author/editor
Muraleedharan, Madhu NairTopakas, EvangelosRova, UlrikaChristakopoulos, PaulKarnaouri, Anthi C.
By organisation
Chemical Engineering
In the same journal
Biotechnology for Biofuels
BioenergyBioprocess Technology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 337 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf