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Publications (10 of 11) Show all publications
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
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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
Witecki, K., Szkurat, M. & Hruzova, K. (2023). Organosolv lignin particles as an ecological reagent in the Kupfershiefer copper ore flotation. Physicochemical Problems of Mineral Processing, 59(6), Article ID 174363.
Open this publication in new window or tab >>Organosolv lignin particles as an ecological reagent in the Kupfershiefer copper ore flotation
2023 (English)In: Physicochemical Problems of Mineral Processing, ISSN 1643-1049, Vol. 59, no 6, article id 174363Article in journal (Refereed) Published
Abstract [en]

Mineral separation relies heavily on the process of flotation. This study explored the feasibility of using organosolv lignin nanoparticles and microparticles (OLP) as a greener alternative to xanthates in the flotation process for mineral separation. Xanthates are widely used but pose environmental and health risks. The efficiency of OLP as collectors was compared to collectorless flotation, resulting in approximately 50% copper recovery, indicating that OLP may not be a suitable replacement for xanthates. Further tests were conducted using a mixture of xanthates and OLP (birch nano and spruce micro) with varying substitution levels (20%, 30%, and 40%). The results demonstrated that increasing the dosage of OLP led to a decrease in flotation efficiency for copper. TOC analysis of the products revealed that high dosages (160 g/t) of birch nano and spruce micro as sole collectors showed beneficiation and selective recovery against copper. While OLPs did not prove effective as collectors, the study highlights their potential as substitutes for maltodextrin in selective flotation of the final concentrate. Two out of four tested OLPs were recommended for pilot scale testing.

Place, publisher, year, edition, pages
Oficyna Wydawnicza Politechniki Wroclawskiej, 2023
Keywords
collector, particles, total organic carbon, organosolv, lignin
National Category
Metallurgy and Metallic Materials Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-102423 (URN)10.37190/ppmp/174363 (DOI)001089303700002 ()
Note

Validerad;2023;NIvå 2;2023-11-14 (marisr);

Funder: EIT RawMaterials GmbH;

License fulltext: CC BY

Available from: 2023-11-13 Created: 2023-11-13 Last updated: 2023-11-14Bibliographically approved
Monção, M., Hrůzová, K., Rova, U., Matsakas, L. & Christakopoulos, P. (2021). Organosolv Fractionation of Birch Sawdust: Establishing a Lignin-First Biorefinery. Molecules, 26(21), 6754-6754
Open this publication in new window or tab >>Organosolv Fractionation of Birch Sawdust: Establishing a Lignin-First Biorefinery
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2021 (English)In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 26, no 21, p. 6754-6754Article in journal (Refereed) Published
Abstract [en]

The use of residual biomass for bioconversions makes it possible to decrease the output of fossil-based chemicals and pursue a greener economy. While the use of lignocellulosic material as sustainable feedstock has been tried at pilot scale, industrial production is not yet economically feasible, requiring further technology and feedstock optimization. The aim of this study was to examine the feasibility of replacing woodchips with residual sawdust in biorefinery applications. Woodchips can be used in value-added processes such as paper pulp production, whereas sawdust is currently used mainly for combustion. The main advantages of sawdust are its large supply and a particle size sufficiently small for the pretreatment process. Whereas, the main challenge is the higher complexity of the lignocellulosic biomass, as it can contain small amounts of bark and cambium. Here, we studied the fractionation of birch sawdust by organosolv pretreatment at two different temperatures and for two different durations. We evaluated the efficiency of fractionation into the three main fractions: lignin, cellulose, and hemicellulose. The cellulose content in pretreated biomass was as high as 69.2%, which was nearly double the amount in untreated biomass. The obtained lignin was of high purity, with a maximum 4.5% of contaminating sugars. Subsequent evaluation of the susceptibility of pretreated solids to enzymatic saccharification revealed glucose yields ranging from 75% to 90% after 48 h but reaching 100.0% under the best conditions. In summary, birch sawdust can be successfully utilized as a feedstock for organosolv fractionation and replace woodchips to simplify and lower the costs of biorefinery processes.

Place, publisher, year, edition, pages
MDPI, 2021
Keywords
organosolv pretreatment, birch, sawdust, fractionation
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-87907 (URN)10.3390/molecules26216754 (DOI)000723145300001 ()34771161 (PubMedID)2-s2.0-85119587466 (Scopus ID)
Funder
Swedish Energy Agency, 2019-005832
Note

Validerad;2021;Nivå 2;2021-11-15 (johcin)

Available from: 2021-11-15 Created: 2021-11-15 Last updated: 2023-09-05Bibliographically approved
Hrůzová, K., Matsakas, L., Rova, U. & Christakopoulos, P. (2021). Organosolv fractionation of spruce bark using ethanol-water mixtures: towards a novel bio-refinery concept. Bioresource Technology, 341, Article ID 125855.
Open this publication in new window or tab >>Organosolv fractionation of spruce bark using ethanol-water mixtures: towards a novel bio-refinery concept
2021 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 341, article id 125855Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to assess the effect of hot water extraction followed by organosolv pretreatment on the enzymatic hydrolysability of spruce bark biomass. To this end, samples were pretreated at five different temperatures in the presence or not of acid catalyst. The cellulose content of pre-treated biomass reached 49.6% w/w. During the enzymatic hydrolysis trials with 3% w/w dry solids, the final hydrolysis yield reached up to 70.1%, which corresponded to the release of 7.8 g/L of glucose. Whereas, the final hydrolysis yield obtained during the high-gravity enzymatic hydrolysis reached up to 43.5%. The concentration of released glucose was in range of 33.3 – 40.0 g/L with a hemicellulose sugars in a range of 5.5 – 6.6 g/L. These values are suitable for downstream bioconversion processes and represent a significant improvement over existing steam pretreatment methods.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Spruce bark, Organosolv fractionation, biorefinery, lignin, Tannin
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-86930 (URN)10.1016/j.biortech.2021.125855 (DOI)000696991200014 ()34523546 (PubMedID)2-s2.0-85114137990 (Scopus ID)
Funder
Swedish Energy Agency, 2018-017714
Note

Validerad;2021;Nivå 2;2021-09-13 (alebob)

Available from: 2021-08-31 Created: 2021-08-31 Last updated: 2023-09-05Bibliographically approved
Hrůzová, K., Matsakas, L., Karnaouri, A., Norén, F., Rova, U. & Christakopoulos, P. (2021). Valorization of outer tunic of the marine filter feeder Ciona intestinalis towards the production of second-generation biofuel and prebiotic oligosaccharides. Biotechnology for Biofuels, 14, Article ID 32.
Open this publication in new window or tab >>Valorization of outer tunic of the marine filter feeder Ciona intestinalis towards the production of second-generation biofuel and prebiotic oligosaccharides
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2021 (English)In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 14, article id 32Article in journal (Refereed) Published
Abstract [en]

Background

One of the sustainable development goals focuses on the biomass-based production as a replacement for fossil-based commodities. A novel feedstock with vast potentials is tunicate biomass, which can be pretreated and fermented in a similar way to lignocellulose. Ciona intestinalis is a marine filter feeder that is cultivated to produce fish feed. While the inner tissue body is used for feed production, the surrounding tunic remains as a cellulose-rich by-product, which can be further separated into outer and inner tunic. Ethanol production from organosolv-pretreated whole-tunic biomass was recently validated. The aim of the present study was to evaluate the potential of organosolv pretreated outer-tunic biomass for the production of biofuels and cellobiose that is a disaccharide with prebiotic potential.

Results

As a result, 41.4 g/L of ethanol by Saccharomyces cerevisiae, corresponding to a 90.2% theoretical yield, was achieved under the optimal conditions when the tunicate biomass was pretreated at 195 °C for 60 min at a liquid-to-solid ratio of 50. In addition, cellobiose production by enzymatic hydrolysis of the pretreated tunicate biomass was demonstrated with a maximum conversion yield of 49.7 wt. %.

Conclusions

The utilisation of tunicate biomass offers an eco-friendly and sustainable alternative for value-added biofuels and chemicals. The cultivation of tunicate biomass in shallow coastal sea improves the quality of the water and ensures sustainable production of fish feed. Moreover, there is no competition for arable land, which leaves the latter available for food and feed production.

Place, publisher, year, edition, pages
Springer Nature, 2021
Keywords
Ciona intestinalis, Tunicate, Bioethanol, Cellobiose, Prebiotics
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-82749 (URN)10.1186/s13068-021-01875-4 (DOI)000616376000001 ()33509271 (PubMedID)2-s2.0-85100202933 (Scopus ID)
Funder
Swedish Energy Agency, 2016–011208Vinnova, 2017–02691
Note

Validerad;2021;Nivå 2;2021-02-02 (alebob)

Available from: 2021-02-02 Created: 2021-02-02 Last updated: 2023-09-05Bibliographically approved
Hruzova, K., Patel, A., Masák, J., Maťátková, O., Rova, U., Christakopoulos, P. & Matsakas, L. (2020). A novel approach for the production of green biosurfactant from Pseudomonas aeruginosa using renewable forest biomass. Science of the Total Environment, 711, Article ID 135099.
Open this publication in new window or tab >>A novel approach for the production of green biosurfactant from Pseudomonas aeruginosa using renewable forest biomass
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2020 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 711, article id 135099Article in journal (Refereed) Published
Abstract [en]

The rising demand for surfactants by the pharmaceuticals and cosmetic industries has generated vast amounts of petroleum-based synthetic surfactants, which are often toxic and non-degradable. Owing to their low toxicity, stability in extreme conditions, and biodegradability, biosurfactants could represent a sustainable alternative. The present study aimed to maximize the production of rhamnolipids (RL) from Pseudomonas aeruginosa by optimizing glucose concentration, temperature, and C/N and C/P ratios. After 96 h of cultivation at 37 °C, the final RL concentration was 4.18 ± 0.19 g/L with a final yield of 0.214 ± 0.010 g/gglucose when pure glucose was used as a carbon source. At present, the main obstacle towards commercialization of RL production is economic sustainability, due to the high cost of downstream processes and media components. For this reason, a renewable source such as wood hydrolysates (from birch and spruce woodchips) was examined here as a possible source of glucose for RL production. Both hydrolysates proved to be adequate, resulting in 2.34 ± 0.17 and 2.31 ± 0.10 g/L of RL, respectively, and corresponding yields of 0.081 ± 0.006 and 0.089 ± 0.004 g/gsugar after 96 h. These results demonstrate the potential of using renewable biomass for the production of biosurfactants and, to the best of our knowledge, they constitute the first report on the use of wood hydrolysates for RL production.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Rhamnolipid, Biosurfactants, Pseudomonas, Wood hydrolysate, Organosolv fractionation
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-76888 (URN)10.1016/j.scitotenv.2019.135099 (DOI)000509344700013 ()32000342 (PubMedID)2-s2.0-85076241604 (Scopus ID)
Note

Validerad;2020;Nivå 2;2020-02-25 (johcin)

Available from: 2019-11-27 Created: 2019-11-27 Last updated: 2023-09-05Bibliographically approved
Hruzova, K., Matsakas, L., Sand, A., Rova, U. & Christakopoulos, P. (2020). Organosolv lignin hydrophobic micro- and nanoparticles as a low-carbon footprint biodegradable flotation collector in mineral flotation. Bioresource Technology, 306, Article ID 123235.
Open this publication in new window or tab >>Organosolv lignin hydrophobic micro- and nanoparticles as a low-carbon footprint biodegradable flotation collector in mineral flotation
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2020 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 306, article id 123235Article in journal (Refereed) Published
Abstract [en]

Flotation is a key step during mineral separation. Xanthates are the most commonly used collectors for recovering Cu, Ni, and Zn from sulphide ores. However, xanthates are fossil-based and toxic for the environment. The aim of this study was to evaluate the use of lignin nanoparticles and microparticles as sustainable and environmentally friendly collectors. Lignin particles demonstrated good selectivity toward Cu (chalcopyrite), with total recoveries exceeding 80% and grades of up to 8.6% w/w from a Cu-Ni ore in rougher flotation tests. When floating Zn-Pb-Cu ore, lignin nanoparticles could reduce the use of xanthates by 50%. Moreover, they outperformed xanthates alone, achieving total recoveries of up to 91%, 85%, and 98% for Cu, Pb, and Zn, respectively. These results prove the potential of lignin as a flotation collector.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Lignin, Nanoparticles, Flotation, Collector, Organosolv
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-78359 (URN)10.1016/j.biortech.2020.123235 (DOI)000532714500003 ()32229063 (PubMedID)2-s2.0-85082530221 (Scopus ID)
Note

Validerad;2020;Nivå 2;2020-05-04 (alebob)

Available from: 2020-04-06 Created: 2020-04-06 Last updated: 2023-09-05Bibliographically approved
Hrůzová, K., Matsakas, L., Karnaouri, A., Norén, F., Rova, U. & Christakopoulos, P. (2020). Second-Generation Biofuel Production from the Marine Filter Feeder Ciona intestinalis. ACS Sustainable Chemistry and Engineering, 8(22), 8373-8380
Open this publication in new window or tab >>Second-Generation Biofuel Production from the Marine Filter Feeder Ciona intestinalis
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2020 (English)In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 8, no 22, p. 8373-8380Article in journal (Refereed) Published
Abstract [en]

Biofuels are essential for transitioning to a sustainable society. This switch can be achieved by introducing novel feedstocks and technologies for efficient and economically feasible biofuel production. Second-generation biofuels are particularly advantageous, as they are produced from nonedible lignocellulosic biomass derived primarily from agricultural byproducts. Ciona intestinalis, a marine filter feeder, is cultivated to produce fish feed from the invertebrate’s inner tissue body. This process generates also vast amounts of a renewable side stream, namely the tunicate’s external cellulose-rich tunic. The aim of the present study was to evaluate the potential of the C. intestinalis tunic as a novel feedstock for bioethanol production. For this purpose, organosolv fractionation of the tunic was optimized to increase cellulose content. Enzymatic saccharification of the pretreated biomass was assessed to identify the most promising materials, which were subsequently utilized as carbon source in fermentation trials. Under optimal conditions, a titer of 38.7 g/L of ethanol, with a yield of 78.3% of the maximum theoretical, was achieved. To the best of our knowledge, this is the first report whereby organosolv pretreated tunic biomass is valorized toward bioethanol production; the current work paves the way for incorporating tunicates in bioconversion processes for the generation of biofuels and other biobased chemicals.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2020
Keywords
Tunicate, Bioethanol, Biofuels, Organosolv, Ciona intestinalis
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-80069 (URN)10.1021/acssuschemeng.0c02417 (DOI)000541445800030 ()2-s2.0-85086631652 (Scopus ID)
Note

Validerad;2020;Nivå 2;2020-07-21 (cisjan)

Available from: 2020-06-29 Created: 2020-06-29 Last updated: 2023-09-05Bibliographically approved
Patel, A., Matsakas, L., Hruzova, K., Rova, U. & Christakopoulos, P. (2019). Biosynthesis of Nutraceutical Fatty Acids by the Oleaginous Marine Microalgae Phaeodactylum tricornutum Utilizing Hydrolysates from Organosolv-Pretreated Birch and Spruce Biomass. Marine Drugs, 17(12), Article ID 119.
Open this publication in new window or tab >>Biosynthesis of Nutraceutical Fatty Acids by the Oleaginous Marine Microalgae Phaeodactylum tricornutum Utilizing Hydrolysates from Organosolv-Pretreated Birch and Spruce Biomass
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2019 (English)In: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 17, no 12, article id 119Article in journal (Refereed) Published
Abstract [en]

Polyunsaturated fatty acids (PUFAs) are essential for human function, however they have to be provided through the diet. As their production from fish oil is environmentally unsustainable, there is demand for new sources of PUFAs. The aim of the present work was to establish the microalgal platform to produce nutraceutical-value PUFAs from forest biomass. To this end, the growth of Phaeodactylum tricornutum on birch and spruce hydrolysates was compared to autotrophic cultivation and glucose synthetic media. Total lipid generated by P. tricornutum grown mixotrophically on glucose, birch, and spruce hydrolysates was 1.21, 1.26, and 1.29 g/L, respectively. The highest eicosapentaenoic acid (EPA) production (256 mg/L) and productivity (19.69 mg/L/d) were observed on spruce hydrolysates. These values were considerably higher than those obtained from the cultivation without glucose (79.80 mg/L and 6.14 mg/L/d, respectively) and also from the photoautotrophic cultivation (26.86 mg/L and 2.44 mg/L/d, respectively). To the best of our knowledge, this is the first report describing the use of forest biomass as raw material for EPA and docosapentaenoic acid (DHA) production.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
polyunsaturated fatty acids, EPA, DHA, marine algae, Phaeodactylum tricornutum, forest biomass
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-73136 (URN)10.3390/md17020119 (DOI)000460795500047 ()30781416 (PubMedID)2-s2.0-85061857091 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-07 (johcin)

Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2023-09-05Bibliographically approved
Patel, A., Hruzova, K., Rova, U., Christakopoulos, P. & Matsakas, L. (2019). Sustainable biorefinery concept for biofuel production through holistic volarization of food waste. Bioresource Technology, 294, Article ID 122247.
Open this publication in new window or tab >>Sustainable biorefinery concept for biofuel production through holistic volarization of food waste
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2019 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 294, article id 122247Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to utilize the whole food waste in two stages. In the first stage, the carbohydrate and protein fractions of food waste recovered after enzymatic hydrolysis was used to cultivate heterotrophic microalgae, resulting in biomass yield of 0.346 ± 0.09 g/gsugars and lipid yield of 0.216 ± 0.06 g/gsugars. In the second stage, oil (14.15% w/w) was extracted from food waste after hydrolysis and converted to biodiesel by a two-step transesterification reaction that generated 135.8 g/kgfood waste of fatty acid methyl esters and 13.8 g/kgfood waste of crude glycerol. Finally, crude glycerol obtained from both processes was used at 20 g/L to cultivate heterotrophic microalgae, resulting in a cell dry weight and total lipid concentration of 6.23 g/L and 2.91 g/L, respectively. A total 248.21 g of fatty acid methyl esters were obtained from the 1 kg of food waste through this integrated process.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Food waste, Enzymatic hydrolysis, Microalgae, Heterotrophic cultivation, Lipids, Fatty acid methyl esters
National Category
Bioprocess Technology
Research subject
Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-76458 (URN)10.1016/j.biortech.2019.122247 (DOI)000492696100060 ()31683456 (PubMedID)2-s2.0-85073202083 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-10-21 (johcin)

Available from: 2019-10-21 Created: 2019-10-21 Last updated: 2023-09-05Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-1132-8947

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