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online series 2021


In Spring 2021, lignin research is in the focus with this online series, arranged by WWSC and Lund University.

Starting end of April, WWSC invites top researchers to give highlights from the latest research on lignin in webinars. The Lignin series ends with an online workshop arranged by Lund University June 16. 

Welcome to join!

Program Spring 2021

April 23rd  14.00

Genetic and cellular regulations of lignin composition in herbaceous and woody plants

Edouard Pesquet

Associate Professor, Stockholm University

Lignins are phenolic heteropolymers which accumulate in cell walls to confer specialized functions to specific cell types such as mechanical resistance, sap conduction or apoplast impermeabilisation. Specific lignins are thus deposited in these different cell types and vary in amounts, composition and localization in the different layers of their cell walls, but also dynamically change to adapt to developmental and environmental constrains [1]. This cellular complexity has represented an important unknown, which hindered the complete understanding of plant lignification and the optimal use of plant biomass for biorefinery processes. To investigate the cellular regulation of lignification in both herbaceous and woody plants, efforts were focused on the optimisation of in situ quantification techniques on whole plant biopsies to directly monitor lignin properties (amount and composition) at the sub-cellular and cellular levels. Two wide-field microspectroscopy methods were optimized, using “RGB-absorbance” and Raman spectroscopy, and validated on sets of synthetic monomers and polymers as well as many genetically engineered plants with modified lignins [2-4]. These optimized methods revealed that the lignification of each cell types resulted from a combination of specific genetic processes, different levels of cellular cooperation and cell wall specific lignin accumulation capacities, which varied during plant development not only to control lignin amount and composition but also residue position in the lignin polymers [2-4]. In the present seminar, these different methods will be presented as well as novel unpublished data on the use of these methods to elucidate the regulation processes controlling the lignification of each specific cell types.     

[1] Pesquet et al. (2019) Current Opinion in Plant Biotechnology –

[2] Blaschek et al., (2020a) Frontiers in Plant Sciences –

[3] Blaschek et al., (2020b) ACS Sustainable Chemistry and Engineering –

[4] Yamamoto et al., (2020) ChemSusChem –

April 30th 11.00

Lignin Nanoparticles as Interfacial Stabilizers: Pickering Emulsions, Enzymatic Catalysis, and Polymeric Composites

Mika Sipponen

Assistant Professor Stockholm University

Register here for the Zoom meeting or watch the stream online

Lignin is a fascinating natural polymer with many essential functions in plant biomass. However, most of the lignin available from industrial processes is still burned due to the lack of commercially feasible routes to value-added materials. Lignin-based polymers1 and especially lignin nanoparticles (LNPs)2 simplify material synthesis by overcoming instability and heterogeneity of crude lignins. LNPs possess a high surface area to mass ratio owing to their anionic surface charge that render these spherical particles colloidally stable. In addition, the amphiphilic nature of LNPs present many opportunities for their use as emulsifiers and surface modification by adsorption. Here, I present our recent work on LNPs as interfacial stabilizers, including Pickering emulsions,3,4 enzymatic catalysis,5 and enzyme-assisted Pickering emulsion polymerization and composite synthesis.6,7 Challenges and future prospects for LNPs as enablers of sustainable materials chemistry will be discussed as well.

  1. Moreno, A. & Sipponen, M. H. Lignin-based smart materials: a roadmap to processing and synthesis for current and future applications. Mater. Horizons 7, 2237–2257 (2020).


  1. Österberg, M., Sipponen, M. H., Mattos, B. D. & Rojas, O. J. Spherical lignin particles: A review on their sustainability and applications. Green Chem. 22, 2712–2733 (2020).


  1. Sipponen, M. H., Smyth, M., Leskinen, T., Johansson, L.-S. & Österberg, M. All-lignin approach to prepare cationic colloidal lignin particles: Stabilization of durable Pickering emulsions. Green Chem. 19, 5831–5840 (2017).


  1. Zou, T., Sipponen, M. H. & Österberg, M. Natural shape-retaining microcapsules with shells made of chitosan- coated colloidal lignin particles. Front. Chem. 7, 370 (2019).


  1. Sipponen, M. H. et al. Spatially confined lignin nanospheres for biocatalytic ester synthesis in aqueous media. Nat. Commun. 9, 1–7 (2018).


  1. Moreno, A. & Sipponen, M. H. Biocatalytic nanoparticles for the stabilization of degassed single electron transfer-living radical pickering emulsion polymerizations. Nat. Commun. 11, 5599 (2020).


  1. Moreno, A., Morsali, M., Liu, J. & Sipponen, M. H. Access to Tough and Transparent Nanocomposites via Pickering Emulsion Polymerization using Biocatalytic Hybrid Lignin Nanoparticles as Functional Surfactants. Green Chem.(2021).

Sipponen lab webpage:

Follow on Twitter: Sipponen lab 


May 4th 11.00

Lignin-based materials

Canceled due to illness

Tetyana Budnyak

Researcher, Stockholm University

May 7th 11.00

Lignin biosynthesis in Norway spruce

Anna Kärkönen

Senior scientist, Natural Resources Institute Finland (Luke)

Lignin constitutes 20–32% of woody plant cell walls, being the second most abundant biopolymer after cellulose. In a growing tree, wood formation with the final phase of lignin deposition occurs in a thin cell layer inside the cambium. The spatial isolation of the developing wood tissue makes the studies related to wood development difficult in muro. In my group, both native trees and a cell culture of Picea abies (Norway spruce) are used to study lignin biosynthesis. The cell culture is a unique system where some cells differentiate into tracheids (ca. 3% of total cells), whereas most of the cells remain undifferentiated. Lignin polymer with a structural similarity to native lignin is constitutively formed in the culture medium (Simola et al. 1992, Warinowski et al. 2016; Giummarella et al. 2019).

The spruce tissue culture line has been an object for several studies focusing on biosynthesis and structure of the extracellular lignin (e.g. Kärkönen et al. 2002; Koutaniemi et al. 2007; Laitinen et al. 2017). The emphasis has been on the enzymes involved in activation of lignin precursors (peroxidases and / or laccases), as well as in the characterisation of the genes for enzymes responsible for monolignol biosynthesis and their polymerisation.

My research interests originated from the observation that H2O2 removal from the culture medium strongly reduces the amounts of extracellular lignin. As H2O2 is needed by peroxidases this data suggest that peroxidases have the main role in activation of monolignols for lignin biosynthesis in the spruce cell culture. This led to the question of the origin of H2O2 in the cell wall during lignin formation. The role of redox active enzymes in plasma membranes, like respiratory burst oxidase homolog, Rboh, have been studied (Kärkönen and Kuchitsu 2015). To study regulation of lignin biosynthesis, a large scale phenolic and transciptomic profiling was conducted using the extracellular lignin-forming cell culture with lignin formation and when lignin formation was inhibited by scavenging of H2O2. This inhibited the action of peroxidases (Laitinen et al. 2017). The results show that apoplastic redox state regulates not only phenolic metabolism, but the whole cellular metabolism. The work also identified several novel proteins (e.g. carbohydrate oxidoreductases) for further evaluation.

In addition to the tissue culture, developing xylem of spruce is used as a research material. The origin of monolignols used in developing tracheids for cell wall lignification has been investigated by RNA-Seq and single cell metabolomics. For RNA-Seq, developing ray parenchymal cells and tracheids were separately collected by laser capture microdissection. In addition, single cell metabolome analysis was conducted in living plantlets, and both monolignols and monolignol glucosides were detected in both cell types (Blokhina et al. 2019). The results show that similarly to that in dicotyledonous species, in Norway spruce ray parenchymal cells contribute in monolignol production in addition to developing tracheids. Currently, the mechanism of transport of monolignols, the precursors for lignin into the apoplast is being studied (Väisänen et al. 2020).

  1. Blokhina O, Laitinen T, Hatakeyama Y, Delhomme N, Paasela T, Zhao L, Street NR, Wada H, Kärkönen A, Fagerstedt KV (2019) Ray cells contribute to monolignol biosynthesis in developing xylem of Norway spruce. Plant Physiol 181: 1552-1572

  2. Giummarella N, Koutaniemi S, Balakshin M, Kärkönen A, Lawoko M (2019) Nativity of lignin carbohydrate bonds substantiated by novel biomimetic synthesis. J Exp Bot 70: 5591-5601

  3. Kärkönen A, Koutaniemi S, Mustonen M, Syrjänen K, Brunow G, Kilpeläinen I, Teeri TH, Simola LK (2002) Lignification related enzymes in Picea abies suspension cultures. Physiol Plant 114: 343-353

  4. Kärkönen A, Kuchitsu K (2015) Reactive oxygen species in cell wall metabolism and development in plants. Phytochemistry, 112: 22–32

  5. Koutaniemi S, Warinowski T, Kärkönen A, Alatalo E, Fossdal CG, Saranpää P, Laakso T, Fagerstedt KV, Simola LK, Paulin L, Rudd S, Teeri TH (2007) Expression profiling of the lignin biosynthetic pathway in Norway spruce using EST sequencing and real-time RT-PCR. Plant Mol Biol 65: 311-328

  6. Laitinen T, Morreel K, Delhomme N, Gauthier A, Schiffthaler B, Nickolov K, Brader G, Lim KJ, Teeri TH, Street NR, Boerjan W, Kärkönen A (2017) A key role for apoplastic H2O2 in Norway spruce phenolic metabolism. Plant Physiol 174: 1449–1475

  7. Simola, LK, Lemmetyinen J, Santanen A (1992) Lignin release and photomixotrophism in suspension cultures of Picea abies. Physiol Plant 84: 374-379

  8. Väisänen E#, Takahashi J, Obudulu O, Bygdell J, Karhunen P, Blokhina O, Laitinen T, Teeri TH, Wingsle G, Fagerstedt KV, Kärkönen A (2020) Hunting monolignol transporters: membrane proteomics and biochemical transport assays with membrane vesicles of Norway spruce. J Exp Bot 71: 6379–6395

  9. Warinowski T, Koutaniemi S, Kärkönen A, Sundberg I, Toikka M, Simola LK, Kilpeläinen I, Teeri TH (2016) Peroxidases bound to the growing lignin polymer produce natural-like extracellular lignin in a cell culture of Norway spruce. Front Plant Sci 7: 1523. doi: 10.3389/fpls.2016.01523.

May 11th 11.00

Analysis of lignin by supercritical fluid technology and high-resolution mass spectrometry

Charlotta Turner

Professor, Department of Chemistry, Centre for Analysis and Synthesis, Lund University 

Chemical analysis of lignin is a multifaceted challenge due to

A. technical lignin samples are often quite complex, containing a “soup” of different compounds and matrix effects can be severe; and

B. chemical standards are usually lacking for many lignin monomers and most lignin oligomers.

This lecture will discuss these challenges and demonstrate solutions for how to accomplish extraction, chromatographic separation and qualitative and quantitative analysis of lignin monomers and oligomers in different types of technical lignin samples. Especially, the use of sub- and supercritical fluid extraction, ultrahigh performance supercritical fluid chromatography and high-resolution mass spectrometry will be discussed. Finally, some preliminary results on uncertainties in molecular weight determination when using size exclusion chromatography, and universal detection by charged aerosol detection, will be presented.

  1. J. Prothmann, et al., Non‐targeted analysis strategy for the identification of phenolic compounds in complex technical lignin samples, ChemSusChem, 2020, 13, 4605-4612.
  2. J. Prothmann, et al., Identification of lignin oligomers in Kraft lignin using ultra-high-performance liquid chromatography/high-resolution multiple-stage tandem mass spectrometry (UHPLC/HRMSn), Anal. Bioanal. Chem., 2018, 410, 7803-7814,
  3. M. Sun, et al., Comprehensive on-line two-dimensional liquid chromatography×supercritical fluid chromatography with trapping column-assisted modulation for depolymerised lignin analysis, J. Chromatogr. A, 2018, 1541, 21-30.
  4. J. Prothmann, et al., Ultrahigh performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) for analysis of lignin-derived monomeric compounds in processed lignin samples, Anal. Bioanal. Chem., 2017, 409, 7049-7061,

May 18th  11.00 

Lignin from a Polymer Synthetic Perspective

Peter Olsén

Researcher, KTH | WWSC 

Lignin is the most abundant aromatic biopolymer found in nature; however, its uses in refined material applications are still scarce. This talk focuses on transforming lignin into functional precursors suitable for material applications by combining fractionation and selective polymerization techniques. Addition polymerization via ring-opening polymerization from the active lignin core has the advantage of retaining the solubility of the copolymer and provides insights into the structural changes that occur to the lignin backbone during synthesis. Understanding how the lignin backbone change during synthesis is vital for transforming lignin into new bio-based materials with predictable and reproducible properties.  The vision is to understand the polymer-synthetic boundaries for lignin, what factors we need to consider, and how we can design systems that make full use of this fantastic biopolymer.

May 21nd  11.00

Lignin-based thermosets

Mats Johansson

Professor, KTH | WWSC

Lignin is an abundant source for aromatic building blocks in thermoset polymers. This presentation will first give a brief background into thermoset polymers in general and how the structure of a thermoset polymer can be designed to obtain suitable properties for various applications. Examples on how this design options can be used to tailor physical and mechanical properties of thermosets built from lignin fractions will then be given. The examples will mainly use functionalized lignin fractions with subsequent crosslinking using thiol-ene chemistry.

May 24th  11.00

Fractionation and modification of “real” lignin

Ola Wallberg, Professor, and Omar Abdelaziz, PhD student,

Lund University 

To label lignin as lignin is very difficult. The production processes that we get lignin from varies a great deal, and that will have a large influence on the lignin characteristics. Common processes where large amounts of lignin can be extracted from are sulfate (Kraft) and sulfite pulping; both being commercially available today. Other biorefinery processes that have been commercialized with varying success are organosolv pulping and bioethanol production based on steam explosion and enzymatic hydrolysis. The isolation method for extracting lignin from the upstream process will also influence the quality of the resulting lignin and the possibility to utilize the lignin in further processing. 

In this  presentation, we will highlight some of the recent developments in biomass fractionation, together with possibilities to further process the extracted lignin streams.


May 28th  11.00

Modification of lignin by transgenic technology in aspen trees

Hannele Touminen

Professor, SLU

This presentation was only available on the time for the seminar

Lignin can be of good and bad: it causes significant problems in both pulping and bioprocessing but is also an interesting raw material for new products. For trees lignin is only of good: it is needed as a building block to keep the woody material intact, to provide hydrophobicity to the water transporting vessels and for many other purposes. We and others have seen that lignin content and composition show large variation between trees in nature, which has prompted us to investigate the underlying molecular mechanisms. I will present some of our recent results in this direction as well as future plans to produce aspen trees with desired lignin properties by genetic engineering.

June 3rd  14.00

Lignin Nanoparticles

Monika Österberg

Professor, Aalto University

Due to recent developments in production scalability as well as promising application prospects, lignin nanoparticles particles (LNPs) have generated increased interest in the research and industrial communities. Transforming lignin into well-defined spherical particles not only enhances the performance of lignin in large volume applications like adhesives, composites or coatings but these particles can also find totally new applications areas like for water purification, sun screen application or for energy storage, to name a few. These advances both enables the replacement of synthetic nanoparticle with biobased alternatives as well promotes lignin valorization, which has been hampered by the complex and varying chemical composition of the available industrial lignin. However, for optimum performance the surface properties of the particle needs to be understood and controlled. To enable this, we have developed thin films from LNPs that can be used to study stability, wetting and adsorption tendency of the LNPs. Our findings show that the self-assembly process renders the LNPs more hydrophilic than lignin films made by dissolution of lignin. In the talk I will also give examples of recent advances in LNP applications. These will include water resistant adhesives, multiresistant coatings, LNPs for virus removal and energy storage

  1. Tao Zou, Alexander Henn, Mika Sipponen, Monika Österberg* (2021) “Solvent-Resistant Lignin-Epoxy Hybrid Nanoparticles for Covalent Surface Modification and High-Strength Particulate Adhesives” ACS Nano DOI 10.1021/acsnano.0c09500

  2. Muhammad Farooq*, Zou Tao, Juan J Valle-Delgado, Mika H. Sipponen, Maria Morits, Monika Österberg* “Well-defined lignin model films from colloidal lignin particles Langmuir (2021)

  3. Österberg, M*, Sipponen, M., Dufao Mattos, B., Rojas O. (2020) “Spherical lignin particles: A review on their sustainability and applications” Green Chemistry 22, 2712-2733, Invited review DOI: 10.1039/d0gc00096e.

  4. Sipponen, M.*, Henn, A., Penttilä P., Österberg, M.* (2020) Lignin-fatty acid hybrid nanocapsules for scalable thermal energy storage in phase-change materials. Chemical Engineering Journal 393, 124711 org/10.1016/j.cej.2020.124711

  5. Rivière, GNS, Korpi, A., Sipponen*, MH, Kostiainen, MA and Österberg M*, (2020) “Agglomeration of viruses by cationic lignin particles for large-scale water purification” ACS Sustainable Chemistry and Engineering 8 (10) 4167-4177.

  6. Zhang, Xue; Morits, Maria; Jonkergouw, Christopher ; Ora, Ari; Valle-Delgado, Juan José; Farooq, Muhammad; Ajdary , Rubina; Huan,Siqi ; Linder, Markus; Rojas, Orlando; Sipponen, Mika; Österberg, Monika* (2020) “Three-dimensional Printed Cell Culture Model Based on Spherical Colloidal Lignin Particles and Cellulose Nanofibril-alginate Hydrogel” Biomacromolecules

June 7th  11.00

Lignin for electrochemical energy storage

Xavier Crispin

Professor, Linköping University | WWSC

June 10th  11.00

Lignin Heterogeneity: Effects on lignin valorization

Martin Lawoko

Professor, KTH | WWSC

Lignin is the most abundant source of renewable aromatics and therefore attractive as a replacement for petroleum-based equivalents for material applications. However, lignin heterogeneity has been pointed out as one of the issues affecting the progress in lignin valorization to valuable materials. This is especially true for the synthesis of materials where precise control is required during the synthesis in order to control the material properties. Prompted by the fast growing research in the area of lignin applications, recent years have seen some progress in efforts to decipher the structure of native- and technical lignin.

Accordingly, lignin research at WWSC KTH, has been devoted to both fundamental aspects of lignin structure, as well as developing deeper understanding of lignin valorization, with major focus on the synthesis and properties of lignin-based thermosets. In this seminar, these two parts will be connected to emphasize the effects of molecular scale heterogeneity at different levels, on lignin valorization. Specific examples from the research group will be discussed in these context.

Tunable thermosetting epoxies based on fractionated and well-characterized lignins
C Gioia*, G Lo Re,  M Lawoko*, L Berglund. J.
Am. Chem. Soc., 2018, 140 (11), 4054-4061

A critical review on the analysis of lignin carbohydrate bonds
N Giummarella, Y Pu, AJ Ragauskas*,
M Lawoko*. Green Chem., 2019, 21 (7), 1573-1595.

New Structures in EucalyptusKraft Lignin with Complex Mechanistic Implications
N Giummarella, IV Pylypchuk, O Sevastyanova, M Lawoko
ACS Sustainable Chem. & Eng. 2020, 8 (29), 10983-10994

Fractional profiling of kraft lignin structure: Unravelling insights on lignin reaction mechanisms
N Giummarella, PA Lindén, D Areskogh, M Lawoko*
ACS Sustainable Chem. & Eng., 2020 (8) 2, 1112-1120.

Lignin-based Epoxiresins: Unravelling the relationship between Structure and Material PropertiesC Gioia*, M. Colonna, A Tagami, L. Medina, O. Sevastyanova, L.A.Berglund, M. LawokoBiomacromolecules 2020, 21, 5, 1920–1928

Toward a Consolidated Lignin Biorefinery: Preserving the Lignin Structure through Additive-Free Protection Strategies.
M Karlsson, N Giummarella, PA Lindén, M Lawoko*.
ChemSusChem 2020, 13(17):4666-4677

Deciphering lignin heterogeneity in ball milled softwood: unravelling the synergy between the supramolecular cell wall structure and molecular events
I Sapouna, M Lawoko*. Green Chemistry, 2021 23 (9), 3348-3364

Recent Strategies for Lignin-Based Thermosets
M Lawoko*, C Gioia
In Lignin Utilization Strategies: From Processing to Applications Chapter 8, pp 175-206
ACS Symposium SeriesVol. 1377 ISBN13: 9780841298453eISBN: 9780841298460
Copyright © 2021 American Chemical Society

June 16th 9.00 – 12.00

Lignin Workshop hosted by Lund University

Full program Lignin workshop June 16 (pdf) >>

note: separate registration

Organisers and contact

Wallenberg Wood Science Center is a research center with a focus on new materials from trees. 
Visit >>

Contact for the series: Martin Lawoko, WWSC 

Lund University. The activities at the Department of Chemical Engineering are environment-related, aimed at a sustainable society. Visit

Contact for the workshop: Gunnar Lidén

Do you have technical questions about the online seminars or registration? Please contact