Change search
Link to record
Permanent link

Direct link
Christakopoulos, PaulORCID iD iconorcid.org/0000-0003-0079-5950
Alternative names
Publications (10 of 353) Show all publications
Wang, D., Zhao, J., Claesson, P., Christakopoulos, P., Rova, U., Matsakas, L., . . . Shi, Y. (2024). A strong enhancement of corrosion and wear resistance of polyurethane-based coating by chemically grafting of organosolv lignin. Materials Today Chemistry, 35, Article ID 101833.
Open this publication in new window or tab >>A strong enhancement of corrosion and wear resistance of polyurethane-based coating by chemically grafting of organosolv lignin
Show others...
2024 (English)In: Materials Today Chemistry, E-ISSN 2468-5194, Vol. 35, article id 101833Article in journal (Refereed) Published
Abstract [en]

Corrosion and wear pose significant challenges to equipment operating in harsh environments. Thus, protective coatings are needed. Anti-corrosion and anti-wear coatings are traditionally fossil-based and often contain environmentally harmful additives. Achieving anti-corrosion and anti-wear coatings based on environmentally benign and sustainable materials is important and a significant challenge. This work focused on the development of organosolv lignin-based polyurethane (OS_lignin-PU) coatings. The coatings were synthesised and evaluated for corrosion protection using electrochemical impedance spectroscopy (EIS) and for wear properties using nanoindentation and nano scratch measurements. EIS revealed that the optimal lignin content for corrosion protection purposes in the OS_lignin-PU coatings was 15 wt%. Moreover, addition of 15 wt% lignin to the OS_lignin-PU coatings also enhanced their wear resistance, as evidenced by reduced thickness loss during tribometer tests. The nano scratch measurements revealed that OS_lignin-PU coatings containing 15 wt% lignin exhibited the lowest scratch depth and friction coefficient. It is found that the developed lignin-containing coating exhibits remarkable corrosion and wear resistance, making it a promising sustainable material in various applications for pursuing sustainable development.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Organosolv lignin, Polyurethane, Coating, Anti-corrosion, Wear resistance
National Category
Corrosion Engineering
Research subject
Machine Elements; Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-103257 (URN)10.1016/j.mtchem.2023.101833 (DOI)
Funder
Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, (Formas, Project No. 2022- 01047, 2021-00728, 2020-01258)
Note

Validerad;2023;Nivå 2;2023-12-08 (joosat);

Full text: CC BY License;

Funder: Engineering and Physical Sciences Research Council (EPSRC), (EP/Y022009/1);

Available from: 2023-12-08 Created: 2023-12-08 Last updated: 2024-02-12Bibliographically approved
Mariam, I., Bettiga, M., Rova, U., Christakopoulos, P., Matsakas, L. & Patel, A. (2024). Ameliorating microalgal OMEGA production using omics platforms. Trends in Plant Science
Open this publication in new window or tab >>Ameliorating microalgal OMEGA production using omics platforms
Show others...
2024 (English)In: Trends in Plant Science, ISSN 1360-1385, E-ISSN 1878-4372Article, review/survey (Refereed) In press
Abstract [en]

Over the past decade, the focus on omega (ω)-3 fatty acids from microalgae has intensified due to their diverse health benefits. Bioprocess optimization has notably increased ω-3 fatty acid yields, yet understanding of the genetic architecture and metabolic pathways of high-yielding strains remains limited. Leveraging genomics, transcriptomics, proteomics, and metabolomics tools can provide vital system-level insights into native ω-3 fatty acid-producing microalgae, further boosting production. In this review, we explore ‘omics’ studies uncovering alternative pathways for ω-3 fatty acid synthesis and genome-wide regulation in response to cultivation parameters. We also emphasize potential targets to fine-tune in order to enhance yield. Despite progress, an integrated omics platform is essential to overcome current bottlenecks in optimizing the process for ω-3 fatty acid production from microalgae, advancing this crucial field.

Place, publisher, year, edition, pages
Elsevier Ltd, 2024
Keywords
bioprocess, genomics, metabolomics, synthetic biology, transcriptomics
National Category
Biochemistry and Molecular Biology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-104361 (URN)10.1016/j.tplants.2024.01.002 (DOI)2-s2.0-85184801441 (Scopus ID)
Note

Funder: Kempestiftelserna (2020-01028, JCK-2115);

Full text license: CC BY

Available from: 2024-02-22 Created: 2024-02-22 Last updated: 2024-02-22
Singh, A., Vidakovic, A., Hjertner, B., Krikigianni, E., Karnaouri, A., Christakopoulos, P., . . . Lundh, T. (2024). Effects of dietary supplementation of lignocellulose-derived cello-oligosaccharides on growth performance, antioxidant capacity, immune response, and intestinal microbiota in rainbow trout (Oncorhynchus mykiss). Aquaculture, 578, Article ID 740002.
Open this publication in new window or tab >>Effects of dietary supplementation of lignocellulose-derived cello-oligosaccharides on growth performance, antioxidant capacity, immune response, and intestinal microbiota in rainbow trout (Oncorhynchus mykiss)
Show others...
2024 (English)In: Aquaculture, ISSN 0044-8486, E-ISSN 1873-5622, Vol. 578, article id 740002Article in journal (Refereed) Published
Abstract [en]

This study evaluated the prebiotic potential of cello-oligosaccharides (COS) produced from birch (Betula pendula), an under-utilised lignocellulosic source from the forestry industry, on growth performance, mucosal immunity, gut microbiota composition, and antioxidant capacity of juvenile rainbow trout (Oncorhynchus mykiss). In a 45-day trial, the fish were fed with diets containing 0%, 0.1%, 0.5% and 1.5% COS, while a diet containing fructo-oligosaccharides (0.5% FOS) was used as a positive control. Fish fed with the 0.5% and 1.5% COS diets showed significantly (P < 0.05) higher abundance of Ruminococcaceae, Bacillaceae and Lactobacillaceae, in the faecal microbiota. The COS diets also induced higher antioxidant capacity in the gut and serum, but there were no treatment effects (P > 0.05) on growth of rainbow trout. Gene expression analysis of the intestine showed significant elevation (P < 0.05) in expression of complement (c3 and c-type lectin) and receptor (tlr2) genes of the innate immune system in COS-fed fish. However, for cytokine and adaptive immune genes, no significant differences (P > 0.05) in gene transcripts were observed between the COS/FOS diets with the control diet. These results suggest that dietary cello-oligosaccharides can be a useful feed supplement for rainbow trout, which can modulate intestinal microbial communities, innate immune response and antioxidant capacity of the host.

Place, publisher, year, edition, pages
Elsevier B.V., 2024
Keywords
Cello-oligosaccharides, Forest waste, Gut immunity, Microbiota, Oxidative stress, Rainbow trout
National Category
Zoology Other Biological Topics
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-101629 (URN)10.1016/j.aquaculture.2023.740002 (DOI)2-s2.0-85171568240 (Scopus ID)
Funder
Vinnova, 2017-02691Swedish Research Council FormasSwedish Energy Agency
Note

Validerad;2023;Nivå 2;2023-10-11 (joosat);

CC BY 4.0 License

Available from: 2023-10-11 Created: 2023-10-11 Last updated: 2023-10-11Bibliographically approved
Thoresen, P. P., Delgado Vellosillo, I., Lange, H., Rova, U., Christakopoulos, P. & Matsakas, L. (2024). Furan Distribution as a Severity Indicator upon Organosolv Fractionation of Hardwood Sawdust through a Novel Ternary Solvent System. ACS Sustainable Chemistry and Engineering, 12(4), 1666-1680
Open this publication in new window or tab >>Furan Distribution as a Severity Indicator upon Organosolv Fractionation of Hardwood Sawdust through a Novel Ternary Solvent System
Show others...
2024 (English)In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 12, no 4, p. 1666-1680Article in journal (Refereed) Published
Abstract [en]

Beech sawdust was treated with a ternary solvent system based on binary aqueous ethanol with partial substitution of ethanol by acetone at four different water contents (60, 50, 40, and 30%v/v). In addition to standard, i.e., noncatalyzed treatments, the application of inorganic acid in the form of 20 mm H2SO4 was evaluated. The various solvent systems were applied at 180 °C for 60 min. The obtained biomass fractions were characterized by standard biomass compositional methods, i.e., sugar monomer and oligomer contents, dehydration product contents of the aqueous product, and lignin, cellulose, and hemicellulose contents in isolated solid fractions. More advanced analyses were performed on the lignin fractions, including quantitative 13C NMR analyses, 1H–13C HSQC analysis, size exclusion chromatography, and pyrolysis-GC/MS, and the aqueous product, in the form of size exclusion chromatography and determination of total phenol contents. The picture emerging from the thorough analytical investigation performed on the lignin fractions is consistent with that resulting from the characterization of the other fractions: results point toward greater deconstruction of the lignocellulosic recalcitrance upon higher organic solvent content, replacing ethanol with acetone during the extraction, and upon addition of mineral acid. A pulp with cellulose content of 94.23 wt % and 95% delignification was obtained for the treatment employing a 55/30/15 EtOH/water/acetone mixture alongside 20 mm H2SO4. Furthermore, the results indicate the formation of two types of organosolv furan families during treatment, which differ in the substitution of their C1 and C5. While the traditional lignin aryl–ether linkages present themselves as indicators for process severity for the nonacid catalyzed systems, the distribution of these furan types can be applied as a severity indicator upon employment of H2SO4, including their presence in the isolated lignin fractions.

Place, publisher, year, edition, pages
American Chemical Society, 2024
Keywords
fractionation, lignin, lignocellulose, organosolv, ternary solvent
National Category
Bioprocess Technology Analytical Chemistry
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-103975 (URN)10.1021/acssuschemeng.3c07236 (DOI)2-s2.0-85182564522 (Scopus ID)
Funder
EU, Horizon 2020, 101007130
Note

Validerad;2024;Nivå 2;2024-01-29 (joosat);

Full text license: CC BY

Available from: 2024-01-29 Created: 2024-01-29 Last updated: 2024-01-29Bibliographically approved
Moncao, M., Paulsen Thoresen, P., Wretborn, T., Lange, H., Rova, U., Christakopoulos, P. & Matsakas, L. (2023). A novel biorefinery concept based on marginally used halophyte biomass. Sustainable Energy & Fuels, 7(16), 3902-3918
Open this publication in new window or tab >>A novel biorefinery concept based on marginally used halophyte biomass
Show others...
2023 (English)In: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 7, no 16, p. 3902-3918Article in journal (Refereed) Published
Abstract [en]

Halophytes have major potential in biorefinery as these salt tolerant crops have prospects as an alternative biomass to meet energy demands and provide value-added products with reduced effects in terms of food security and environmental damage when compared to other crops. In this study, we investigated the effects of organosolv pretreatment process parameters on the fractionation of residual fibers from pressed Salicornia ramosissima and how it affects the fractions of cellulose, lignin, and hemicelluloses. Pretreated pulps contained as high as 48.95% w/w cellulose, a 2.9-fold increase from the untreated fibers. The delignification of pulp was as high as 75.01% and hemicellulose removal reached 96.38%. The hemicellulose fractions contained as high as 78.49% oligomers and we identified up to 30.4% linear xylooligosaccharides in the composition. The majority of the fragments of hemicelluloses had molecular weights lower than 1000 Da. Isolated lignin samples had in most cases very low sugar and ash contamination with a reduced molecular weight. The typical G-, S-, and H-type aromatic units were detected in the lignin, together with & beta;-O-4 & PRIME;, & beta;-5 & PRIME;, & beta;-& beta;& PRIME;, and dibenzodioxocine links. The results suggest a novel applicability of S. ramosissima in a biorefinery context with fractionation deriving building blocks for value added products.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2023
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-99275 (URN)10.1039/d3se00458a (DOI)001029749000001 ()2-s2.0-85166210013 (Scopus ID)
Funder
EU, Horizon 2020, 862834
Note

Validerad;2023;Nivå 2;2023-08-16 (joosat);

Licens fulltext: CC BY License

Available from: 2023-08-07 Created: 2023-08-07 Last updated: 2023-09-05Bibliographically approved
Karageorgou, D., Rova, U., Christakopoulos, P., Katapodis, P., Matsakas, L. & Patel, A. (2023). Benefits of supplementation with microbial omega-3 fatty acids on human health and the current market scenario for fish-free omega-3 fatty acid. Trends in Food Science & Technology, 136, 169-180
Open this publication in new window or tab >>Benefits of supplementation with microbial omega-3 fatty acids on human health and the current market scenario for fish-free omega-3 fatty acid
Show others...
2023 (English)In: Trends in Food Science & Technology, ISSN 0924-2244, E-ISSN 1879-3053, Vol. 136, p. 169-180Article, review/survey (Refereed) Published
Abstract [en]

BackgroundGrowing evidence points to a link between specific fatty acids ingested through the diet and human health. Chain length, saturation degree, and position of double bonds in fatty acids determine their effect in humans. Omega-3 and omega-6 fatty acids have been recognized for their contribution to the prevention and/or treatment of diabetes, cancer, visual impairment, cardiovascular diseases, as well as neurological and musculoskeletal disorders.

Scope and approachHumans cannot synthesize these fatty acids in sufficient amounts and need to absorb them through the diet. Oleaginous microalgae constitute a promising, sustainable source of such fatty acids, as they can accumulate up to 85% of lipids on a cell dry weight basis.

Key findings and conclusionsThe present review summarizes the potential of oleaginous microalgae as a convenient, economical, and sustainable source of polyunsaturated fatty acids, and explores their beneficial role in human health. The growing prevalence of cardiovascular diseases and changing dietary preferences are driving the increasing demand for microbial omega-3 fatty acids. Following the COVID-19 pandemic, the importance of a healthy immune system has further strengthened the market for omega-3 fatty acids.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Human health, Nutraceutical fatty acids, oleaginous microalgae, Omega-3, Omega-6, PUFAs
National Category
Nutrition and Dietetics Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-97073 (URN)10.1016/j.tifs.2023.04.018 (DOI)2-s2.0-85154542373 (Scopus ID)
Projects
Green and sustainable approach to valorise high saline and oily fish processing effluents for production of nutraceuticalsBoosting the squalene content in thraustochytrids by genetic engineering using CRISPR–Cas9 System to replace shark-based squalene as an adjuvant for COVID 2019 vaccine
Funder
The Kempe FoundationsSwedish Research Council Formas, JCK-2115 L3, 2020-01028
Note

Validerad;2023;Nivå 2;2023-05-12 (hanlid);

Funder: Hellenic Foundation for Research and Innovation (HFRI) and the General Secretariat for Research and Technology (GSRT) (1137)

Available from: 2023-05-12 Created: 2023-05-12 Last updated: 2023-09-05Bibliographically approved
Hruzova, K., Kolman, K., Matsakas, L., Nordberg, H., Christakopoulos, P. & Rova, U. (2023). Characterization of Organosolv Lignin Particles and Their Affinity to Sulfide Mineral Surfaces. ACS Applied Nano Materials, 6(19), 17349-18631
Open this publication in new window or tab >>Characterization of Organosolv Lignin Particles and Their Affinity to Sulfide Mineral Surfaces
Show others...
2023 (English)In: ACS Applied Nano Materials, E-ISSN 2574-0970, Vol. 6, no 19, p. 17349-18631Article in journal (Refereed) Published
Abstract [en]

Organosolv lignin nanoparticles have been recently evaluated for their use in mineral froth flotation as a flotation reagent, and as a result, the recovery of the target minerals was improved and the selectivity of the process was increased. However, the mechanism of lignin activity in mineral froth flotation is not known. Therefore, this study is the first step in understanding the interaction of organosolv lignin with the mineral surface. As such, the organosolv lignin was characterized by GPC and 31P NMR, where the structural differences between the birch and spruce lignins were determined. The molecular size and lignol unit composition were evaluated. Subsequently, the morphology and size of the organosolv lignin particles were examined for all 4 produced types: BN, BM, SN, and SM. The ? potential was measured in the pH range of 2-11. All particles had a high negative charge, which indicated good stability of the dispersion in the alkali range. The stability of their colloidal dispersion was observed under increasing concentrations of mono- and divalent cations, and electrostatic repulsion was identified as the main stabilization mechanism. Finally, QCM-D was used to study the interaction of the lignin particles with the mineral surfaces of chalcopyrite, pyrite, and galena, which gave insight into the possible mechanism during the flotation process.

Place, publisher, year, edition, pages
Amer Chemical Soc, 2023
Keywords
organosolv lignin, nanoparticles, microparticles, surface chemistry, mineral surfaces, QCM-D
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-101664 (URN)10.1021/acsanm.3c02069 (DOI)001068455100001 ()
Funder
Vinnova, LIGNOFLOT project (2017-05456)
Note

Validerad;2023;Nivå 2;2023-10-16 (joosat);

CC BY 4.0 License

Available from: 2023-10-16 Created: 2023-10-16 Last updated: 2023-10-16Bibliographically approved
Paulsen Thoresen, P., Lange, H., Rova, U., Christakopoulos, P. & Matsakas, L. (2023). Covalently bound humin-lignin hybrids as important novel substructures in organosolv spruce lignins. International Journal of Biological Macromolecules, 233, Article ID 123471.
Open this publication in new window or tab >>Covalently bound humin-lignin hybrids as important novel substructures in organosolv spruce lignins
Show others...
2023 (English)In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 233, article id 123471Article in journal (Refereed) Published
Abstract [en]

Organosolv lignins (OSLs) are important byproducts of the cellulose-centred biorefinery that need to be converted in high value-added products for economic viability. Yet, OSLs occasionally display characteristics that are unexpected looking at the lignin motifs present. Applying advanced NMR, GPC, and thermal analyses, isolated spruce lignins were analysed to correlate organosolv process severity to the structural details for delineating potential valorisations. Very mild conditions were found to not fractionate the biomass, causing a mix of sugars, lignin-carbohydrate complexes (LCCs), and corresponding dehydration/degradation products and including pseudo-lignins. Employing only slightly harsher conditions promote fractionation, but also formation of sugar degradation structures that covalently incorporate into the oligomeric and polymeric lignin structures, causing the isolated organosolv lignins to contain lignin-humin hybrid (HLH) structures not yet evidenced as such in organosolv lignins. These structures effortlessly explain observed unexpected solubility issues and unusual thermal responses, and their presence might have to be acknowledged in downstream lignin valorisation.

Place, publisher, year, edition, pages
Elsevier B.V., 2023
Keywords
Humins, Organosolv lignin, Structure elucidation
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-95765 (URN)10.1016/j.ijbiomac.2023.123471 (DOI)36736515 (PubMedID)2-s2.0-85148062762 (Scopus ID)
Funder
Swedish Research Council Formas, 2016-20022Bio4Energy
Note

Validerad;2023;Nivå 2;2023-03-06 (joosat);

Funder: COST (European Cooperation in Science and Technology), (CA17128); University of Milano-Bicocca; University of Naples ‘Federico II’

Available from: 2023-03-06 Created: 2023-03-06 Last updated: 2023-09-05Bibliographically approved
Wu, Z., Paulsen Thoresen, P., Matsakas, L., Rova, U., Christakopoulos, P. & Shi, Y. (2023). Facile Synthesis of Lignin-Castor Oil-Based Oleogels as Green Lubricating Greases with Excellent Lubricating and Antioxidation Properties. ACS Sustainable Chemistry and Engineering, 11(34), 12478-12858
Open this publication in new window or tab >>Facile Synthesis of Lignin-Castor Oil-Based Oleogels as Green Lubricating Greases with Excellent Lubricating and Antioxidation Properties
Show others...
2023 (English)In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 11, no 34, p. 12478-12858Article in journal (Refereed) Published
Abstract [en]

In this study, a facile synthesis method was employed to create lignin-castor oil-based oleogels by modifying organic lignin with two silane coupling agents. The resulting oleogels demonstrated outstanding lubricating and antioxidation properties, establishing them as promising green lubricating greases. Compared with the pure castor oil, the oxidation induction time (OIT) value of the synthesized oleogels was significantly increased from 20 s (pure castor oil) to 1959 s (oleogel with 20 wt % lignin), indicating an effective improvement of the oxidation resistance. The steel contacts lubricated by the synthesized oleogel also had lower wear than those lubricated by pure castor oil, signifying the better lubricating properties of oleogels. The oleogel with 20 wt % lignin showed the lowest wear, which was around 64% lower than that of pure castor oil. The exceptional performance and environmentally sustainable composition of these oleogels, with the biomass content exceeding 80%, allow them to be used as green lubricating greases for industrial applications. Overall, this study provides valuable insights into the development of high-performance, eco-friendly lubricants.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
Keywords
lignin, castor oil, antioxidant, antiwear, oleogel
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Biochemical Process Engineering; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-101255 (URN)10.1021/acssuschemeng.3c01801 (DOI)001048112300001 ()
Funder
Swedish Research Council Formas, 2019-00904, 2022-01047Swedish Research Council, 2019-04941
Note

Validerad;2023;Nivå 2;2023-09-06 (joosat);

CC BY 4.0 License

 

Available from: 2023-09-06 Created: 2023-09-06 Last updated: 2023-09-06Bibliographically approved
Vyas, S. R., Matsakas, L., Rova, U., Christakopoulos, P. & Patel, A. (2023). Insights into hydrophobic waste valorization for the production of value-added oleochemicals. Microbial Biotechnology, 16(2), 177-183
Open this publication in new window or tab >>Insights into hydrophobic waste valorization for the production of value-added oleochemicals
Show others...
2023 (English)In: Microbial Biotechnology, ISSN 1751-7907, E-ISSN 1751-7915, Vol. 16, no 2, p. 177-183Article in journal, Editorial material (Other academic) Published
Place, publisher, year, edition, pages
John Wiley & Sons, 2023
National Category
Chemical Process Engineering
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-92558 (URN)10.1111/1751-7915.14122 (DOI)000836948600001 ()35932161 (PubMedID)2-s2.0-85135480800 (Scopus ID)
Projects
Green and sustainable approach to valorise high saline and oily fish processing effluents for the production of nu-traceuticals (INVENTION; 2020-01028)
Funder
The Kempe Foundations, JCK‐2115Swedish Research Council Formas, 2020‐01028
Note

Godkänd;2023;Nivå 0;2023-04-21 (hanlid);

Available from: 2022-08-23 Created: 2022-08-23 Last updated: 2023-09-05Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0079-5950

Search in DiVA

Show all publications