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Christakopoulos, PaulORCID iD iconorcid.org/0000-0003-0079-5950
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Publikasjoner (10 av 371) Visa alla publikasjoner
Upadhyayula, V. K. .., Yacout, D. M. .., Latham, K. G., Jansson, S., Rova, U., Christakopoulos, P. & Matsakas, L. (2025). Organosolv lignin carbon fibers and their prospective application in wind turbine blades: An environmental performance assessment. Journal of Cleaner Production, 491, Article ID 144825.
Åpne denne publikasjonen i ny fane eller vindu >>Organosolv lignin carbon fibers and their prospective application in wind turbine blades: An environmental performance assessment
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2025 (engelsk)Inngår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 491, artikkel-id 144825Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Lignin is a potential sustainable alternative to polyacrylonitrile (PAN) precursor for the production of carbon fibers. The high purity lignin extracted from residual forest biomass via organosolv process undergoes stabilization and carbonization treatment to produce carbon fibers. Recent developments suggest the potential of producing organosolv lignin carbon fibers (OLCF) with competing mechanical properties similar to PAN carbon fibers. This is likely to enable the use of OLCF in structurally demanding applications such as wind turbine blades. In this work, a life cycle assessment (LCA) is performed with a threefold objective. First, the environmental footprint of OLCF is quantified and results are compared with PAN-CF produced in Sweden and elsewhere in Europe i.e., electricity demands met by European average electrical grid (RER). Second, the environmental performance of OLCF reinforced wind turbine blades (referred as BIOMAT) to be installed in 0.8 MW capacity is evaluated against incumbent variants: glass fiber turbine blade (GFTB), PAN-CF based turbine blades manufactured in Sweden (CFTB-SE), and other parts of Europe (CFTB-RER). Finally, the total environmental externality costs (EEC) of these blades and corresponding lifetime electricity generation when they are installed in 0.8 MW capacity wind turbine blade are calculated. Our results indicate that the environmental impacts of OLCF are lower by 71–94% than PAN-CF-RER in nine, and lower by 43–90% than PAN-CF-SE in six out of ten impact categories quantified respectively. BIOMAT blades also have better overall environmental performance than existing blade variants and particularly lucrative because of their negative total climate change impact. The total EEC of BIOMAT blades is 74%, 83% and 88% lower than GFTB, CFTB-SE and CFTB-RER respectively. Correspondingly, the total EEC of lifetime electricity generated by wind turbine equipped with BIOMAT blades is 11%, 17% and 23% lower than the respective blade variants.

sted, utgiver, år, opplag, sider
Elsevier Ltd, 2025
Emneord
Organosolv lignin, Carbon fibers, Wind turbine blades, Environmental impact, Environmental externality costs, Environmental benefits to investment ratio
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-111539 (URN)10.1016/j.jclepro.2025.144825 (DOI)2-s2.0-85215856768 (Scopus ID)
Forskningsfinansiär
Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 2016-20022Bio4Energy
Merknad

Validerad;2025;Nivå 2;2025-02-05 (u2);

Full text: CC BY license;

Tilgjengelig fra: 2025-02-05 Laget: 2025-02-05 Sist oppdatert: 2025-02-05bibliografisk kontrollert
Krikigianni, E., Antoniadis, K., Christakopoulos, P., Rova, U., Matsakas, L. & Patel, A. (2025). Strategic bioprocessing of A. protothecoides and C. sorokiniana using renewable feedstocks for targeted bioproduct and biodiesel generation. Energy Conversion and Management: X, 26, Article ID 100896.
Åpne denne publikasjonen i ny fane eller vindu >>Strategic bioprocessing of A. protothecoides and C. sorokiniana using renewable feedstocks for targeted bioproduct and biodiesel generation
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2025 (engelsk)Inngår i: Energy Conversion and Management: X, E-ISSN 2590-1745, Vol. 26, artikkel-id 100896Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The focus on sustainability and circular economy renders the microalgal biorefinery concept highly attractive. Although the diversity of microalgal composition makes them ideal feedstocks, their metabolic versatility challenges bioprocess optimization. To address this, an integrated, strain-specific approach was used to evaluate key cultivation parameters (nitrogen source, C/N ratio, and light intensity) as their interactions affect growth performance and biochemical composition. Heterotrophic cultivation of A. protothecoides (AP) and C. sorokiniana (CS) in glucose showed enhanced cell growth with organic N-sources. Biomass was consistently elevated across C/N ratios from 5 to 60 with corn steep liquor (CSL) (8.1 g L-1) and yeast extract (YE) (7.0 g L-1), while with urea it maximized at C/N 5 (6.2 g L-1). Protein synthesis increased at C/N 5, whereas lipid accumulation at C/N 60. Beechwood hydrolysate, a renewable glucose alternative, produced an average of 4.1 g L-1 protein (C/N 5) and 3.5 g L-1 lipids (C/N 60) between YE and CSL. Mixotrophic cultivation indicated better photosynthetic adaptation of AP at C/N 5, yielding 13.2 g L-1 biomass at 400 μmol m-2 s-1, whereas at C/N 60 growth was favored at 50 μmol m-2 s-1. The fatty acid profile of microalgal oil revealed de novo biosynthesis of odd-chain fatty acids at C/N 5 in both cultivation modes, while biodiesel-grade lipids produced in heterotrophic condition. These findings advance microalgal bioprocessing by emphasizing the importance of fine-tuning cultivation strategies and utilizing renewable nutrients to maximize resource efficiency and optimize the biosynthesis of valuable bioproducts, such as proteins, pigments, carbohydrates, and high-quality lipids.

sted, utgiver, år, opplag, sider
Elsevier Ltd, 2025
Emneord
Microalgal biorefinery, Auxenochlorella protothecoides, Chlorella sorokiniana, Biodiesel, Odd-chain fatty acids, Protein, Lignocellulosic hydrolysate
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-111554 (URN)10.1016/j.ecmx.2025.100896 (DOI)2-s2.0-85215940542 (Scopus ID)
Forskningsfinansiär
EU, Horizon 2020, 101007130
Merknad

Validerad;2025;Nivå 1;2025-02-06 (u8);

Full text license: CC BY 4.0

Tilgjengelig fra: 2025-02-06 Laget: 2025-02-06 Sist oppdatert: 2025-02-06bibliografisk kontrollert
Patel, A., Rantzos, C., Krikigianni, E., Rova, U., Christakopoulos, P. & Matsakas, L. (2024). A bioprocess engineering approach for the production of hydrocarbons and fatty acids from green microalga under high cobalt concentration as the feedstock of high-grade biofuels. Biotechnology for Biofuels and Bioproducts, 17, Article ID 64.
Åpne denne publikasjonen i ny fane eller vindu >>A bioprocess engineering approach for the production of hydrocarbons and fatty acids from green microalga under high cobalt concentration as the feedstock of high-grade biofuels
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2024 (engelsk)Inngår i: Biotechnology for Biofuels and Bioproducts, E-ISSN 2731-3654, Vol. 17, artikkel-id 64Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Botryococcus braunii, a colonial green microalga which is well-known for its capacity to synthesize hydrocarbons, has significant promise as a long-term source of feedstock for the generation of biofuels. However, cultivating and scaling up B. braunii using conventional aqua-suspended cultivation systems remains a challenge. In this study, we optimized medium components and light intensity to enhance lipid and hydrocarbon production in a multi-cultivator airlift photobioreactor. BBM 3N medium with 200 μmol/m2/s light intensity and a 16 h light–8 h dark regimen yielded the highest biomass productivity (110.00 ± 2.88 mg/L/day), as well as the highest lipid and hydrocarbon content. Cultivation in a flat-panel bioreactor resulted in significantly higher biomass productivity (129.11 ± 2.74 mg/L/day), lipid productivity (32.21 ± 1.31 mg/L/day), and hydrocarbon productivity (28.98 ± 2.08 mg/L/day) compared to cultivation in Erlenmeyer flasks and open 20-L raceway pond. It also exhibited 20.15 ± 1.03% of protein content including elevated levels of chlorophyll a, chlorophyll b, and carotenoids. This work is noteworthy since it is the first to describe fatty acid and hydrocarbon profiles of B. braunii during cobalt treatment. The study demonstrated that high cobalt concentrations (up to 5 mg/L of cobalt nitrate) during Botryococcus culture affected hydrocarbon synthesis, resulting in high amounts of n-alkadienes and trienes as well as lipids with elevated monounsaturated fatty acids concentration. Furthermore, pyrolysis experiments on microalgal green biomass and de-oiled biomass revealed the lipid and hydrocarbon compounds generated by the thermal degradation of B. braunii that facilitate extra economical value to this system.

sted, utgiver, år, opplag, sider
Springer Nature, 2024
Emneord
Biofuels, Botryococcus braunii, Fatty acids, Hydrocarbons, Open raceway pond, Pyrolysis
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-105619 (URN)10.1186/s13068-024-02512-6 (DOI)001218454600002 ()38730294 (PubMedID)2-s2.0-85192981459 (Scopus ID)
Merknad

Validerad;2024;Nivå 2;2024-07-10 (joosat);

Funder: European Union’s Horizon 2020 (101007130); 

Full text license: CC BY 4.0;

Tilgjengelig fra: 2024-06-04 Laget: 2024-06-04 Sist oppdatert: 2024-07-10bibliografisk kontrollert
Monção, M., Anukam, A. I., Hrůzová, K., Rova, U., Christakopoulos, P. & Matsakas, L. (2024). A Parametric Study of the Organosolv Fractionation of Norway Spruce Sawdust. Energies, 17(13), Article ID 3276.
Åpne denne publikasjonen i ny fane eller vindu >>A Parametric Study of the Organosolv Fractionation of Norway Spruce Sawdust
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2024 (engelsk)Inngår i: Energies, E-ISSN 1996-1073, Vol. 17, nr 13, artikkel-id 3276Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Lignocellulosic biomass represents an excellent alternative to fossil fuels in terms of both energy production and raw material usage for a plethora of daily-use products. Organosolv pretreatment is a fractionation technique able to separate lignocellulosic biomass into individual streams of cellulose, hemicellulose, and lignin under controlled conditions. Sawdust, the by-product of sawmill processing of Picea abies wood, was the subject of our investigation in this work. The aim was to evaluate the effects of different parameters of the organosolv process of spruce sawdust on the yield of components and how this affects the enzymatic saccharification of cellulose. Sixteen distinct pretreatments were performed with ethanol concentrations of 50 and 60% v/v at 180 and 200 °C for 15 and 30 min. Half of the pretreatments contained 1% sulfuric acid as a catalyst, while the other half were acid-free. Thereafter, the effects of different variables on the yield of products were assessed and compared to determine the ideal pretreatment condition. The results showed that cellulose-rich pulps, with cellulose content as high as 55% were generated from an initial mass of 37.7% spruce sawdust with the reactor operating at 180 °C for 30 min using 60% ethanol and 1% sulfuric acid. With the pretreatments performed with the catalyst at 200 °C, hemicellulose was almost entirely removed from the pulps obtained. The recovered hemicellulose fraction was composed mainly of monomers achieving up to 10 g/100 g of biomass. Delignification values of up to 65.7% were achieved with this pretreatment technique. Fractionated lignin presented low levels of sugar and ashes contamination, with values as low as 1.29% w/w. Enzymatic saccharification of the pretreated pulps yielded 78% cellulose hydrolysis, with glucose release higher than 0.54 g/g of biomass, indicating the potential of the pulps to be applied in a fermentation process.

sted, utgiver, år, opplag, sider
MDPI, 2024
Emneord
biorefinery, organosolv, pretreatment, saccharification, sawdust
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-108408 (URN)10.3390/en17133276 (DOI)001269263400001 ()2-s2.0-85198221327 (Scopus ID)
Forskningsfinansiär
Swedish Energy Agency, 2022-201046
Merknad

Validerad;2024;Nivå 2;2024-07-29 (signyg);

Full text license: CC BY

Tilgjengelig fra: 2024-07-29 Laget: 2024-07-29 Sist oppdatert: 2024-07-29bibliografisk kontrollert
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.
Åpne denne publikasjonen i ny fane eller vindu >>A strong enhancement of corrosion and wear resistance of polyurethane-based coating by chemically grafting of organosolv lignin
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2024 (engelsk)Inngår i: Materials Today Chemistry, E-ISSN 2468-5194, Vol. 35, artikkel-id 101833Artikkel i tidsskrift (Fagfellevurdert) 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.

sted, utgiver, år, opplag, sider
Elsevier, 2024
Emneord
Organosolv lignin, Polyurethane, Coating, Anti-corrosion, Wear resistance
HSV kategori
Forskningsprogram
Maskinelement; Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-103257 (URN)10.1016/j.mtchem.2023.101833 (DOI)001135558500001 ()2-s2.0-85179131576 (Scopus ID)
Forskningsfinansiär
Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, (Formas, Project No. 2022- 01047, 2021-00728, 2020-01258)
Merknad

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

Full text: CC BY License;

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

Tilgjengelig fra: 2023-12-08 Laget: 2023-12-08 Sist oppdatert: 2025-02-09bibliografisk kontrollert
Mariam, I., Bettiga, M., Rova, U., Christakopoulos, P., Matsakas, L. & Patel, A. (2024). Ameliorating microalgal OMEGA production using omics platforms. Trends in Plant Science, 29(7), 799-813
Åpne denne publikasjonen i ny fane eller vindu >>Ameliorating microalgal OMEGA production using omics platforms
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2024 (engelsk)Inngår i: Trends in Plant Science, ISSN 1360-1385, E-ISSN 1878-4372, Vol. 29, nr 7, s. 799-813Artikkel, forskningsoversikt (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
Elsevier, 2024
Emneord
bioprocess, genomics, metabolomics, synthetic biology, transcriptomics
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-104361 (URN)10.1016/j.tplants.2024.01.002 (DOI)001265637800001 ()38350829 (PubMedID)2-s2.0-85184801441 (Scopus ID)
Merknad

Validerad;2024;Nivå 2;2024-08-16 (marisr);

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

Full text license: CC BY

Tilgjengelig fra: 2024-02-22 Laget: 2024-02-22 Sist oppdatert: 2024-08-16bibliografisk kontrollert
Jampala, A. M., Bajracharya, S., Matsakas, L., Rova, U. & Christakopoulos, P. (2024). Bioelectrochemical treatment of acid mine drainage: Microbiome synergy influences sulfidogenesis and acetogenesis. Sustainable Chemistry for the Environment, 6, Article ID 100106.
Åpne denne publikasjonen i ny fane eller vindu >>Bioelectrochemical treatment of acid mine drainage: Microbiome synergy influences sulfidogenesis and acetogenesis
Vise andre…
2024 (engelsk)Inngår i: Sustainable Chemistry for the Environment, E-ISSN 2949-8392, Vol. 6, artikkel-id 100106Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Bioelectrochemical systems (BES) are emerging as potential technologies that can remediate acid mine drainage (AMD) by cathodic reduction of sulfates to metal sulfides. This study evaluated bioelectrochemical remediation of sulfate rich AMD at two applied cathode potentials; BES-1: −1.0 V and BES-2: −0.8 V. Sulfate reducing bacteria were selectively enriched to be used as biocatalyst in BES. Initially, lactate was fed as carbon source and switched to chemolithoautotrophy with only CO2-fed conditions. Both BESs were operated at 3±0.2 g/l of sulfate with synthetic AMD (SAMD) fed first, and gradually changed to 50% AMD from mining site with 50% SAMD. Sulfate reduction was relatively higher with BES-1: 82% than BES-2: 76% coupled with sulfidogenesis. Interestingly, acetogenesis (BES-1: 2.12±0.2 g/l, BES-2: 1.9±0.2 g/l) was also noticed with high reduction currents (BES-1&2: >-70 mA). Microbiome community analysis revealed the dominant presence of sulfate reducers, acetogens, syntrophic bacteria and Methanobacterium, probing microbial synergy aiding sulfate reduction. An added advantage was the iron-sulfide (FeS) particles formation on cathode, which might have contributed to increased reduction currents. This study reveals insights into microbial synergy for autotrophic sulfate reduction within mixed microbiome communities along with the impact of FeS particles as conducive facilitator for electron transfer in BES, thereby enhancing electrosynthetic acetate production.

sted, utgiver, år, opplag, sider
Elsevier, 2024
Emneord
Acid mine drainage, Autotrophic sulfate reduction, Bioremediation, Metal sulfides, Microbial synergy
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-105442 (URN)10.1016/j.scenv.2024.100106 (DOI)2-s2.0-85192149058 (Scopus ID)
Prosjekter
Novel BIOelectrochemical systems for integrated Energy harvesting and bioremediation of acid MINe Drainage (BIOeMIND)Recovery and co-GeneratIon of metals and energy by sustainable acid mine drainage treatment (REGAIN)
Forskningsfinansiär
Swedish Research Council Formas, 2021-01084Luleå University of Technology, SUN
Merknad

Godkänd;2024;Nivå 0;2024-05-13 (hanlid);

Full text license: CC BY-NC

Tilgjengelig fra: 2024-05-13 Laget: 2024-05-13 Sist oppdatert: 2024-05-13bibliografisk kontrollert
Sarkar, O., Rova, U., Christakopoulos, P. & Matsakas, L. (2024). Biogas potential of organosolv pretreated wheat straw as mono and co-substrate: substrate synergy and microbial dynamics. Scientific Reports, 14, Article ID 18442.
Åpne denne publikasjonen i ny fane eller vindu >>Biogas potential of organosolv pretreated wheat straw as mono and co-substrate: substrate synergy and microbial dynamics
2024 (engelsk)Inngår i: Scientific Reports, E-ISSN 2045-2322, Vol. 14, artikkel-id 18442Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Anaerobic digestion (AD) technology can potentially address the gap between energy demand and supply playing a crucial role in the production of sustainable energy from utilization of biogenic waste materials as feedstock. The biogas production from anaerobic digestion is primarily influenced by the chemical compositions and biodegradability of the feedstock. Organosolv-steam explosion offers a constructive approach as a promising pretreatment method for the fractionation of lignocellulosic biomasses delivering high cellulose content.This study showed how synergetic co-digestion serves to overcome the challenges of mono-digestion's low efficiency. Particularly, the study evaluated the digestibility of organosolv-steam pretreated wheat straw (WSOSOL) in mono as well as co-digesting substrate with cheese whey (CW) and brewery spent grains (BSG). The highest methane yield was attained with co-digestion of WSOSOL + CW (338 mL/gVS) representing an enhanced biogas output of 1–1.15 times greater than its mono digestion. An ammonium production was favored under co-digestion strategy accounting for 921 mg/L from WSOSOL + BSG. Metagenomic study was conducted to determine the predominant bacteria and archaea, as well as its variations in their populations and their functional contributions during the AD process. The Firmicutes have been identified as playing a significant role in the hydrolysis process and the initial stages of AD. An enrichment of the most prevalent archaea genera enriched were Methanobacterium, Methanothrix, and Methanosarsina. Reactors digesting simpler substrate CW followed the acetoclastic, while digesting more complex substrates like BSG and WSOSOL followed the hydrogenotrophic pathway for biomethane production. To regulate the process for an enhanced AD process to maximize CH4, a comprehensive understanding of microbial communities is beneficial.

sted, utgiver, år, opplag, sider
Springer Nature, 2024
Emneord
Anaerobic digestion, Bio-fertilizer, Bioammonium, Co-fermentation, Organosolv pretreatment, Wheat straw
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-108611 (URN)10.1038/s41598-024-68904-8 (DOI)001294094100021 ()39117660 (PubMedID)2-s2.0-85200849237 (Scopus ID)
Forskningsfinansiär
Bio4Energy, B4E3-FM-1-10
Merknad

Validerad;2024;Nivå 2;2024-11-14 (sarsun);

Full text license: CC BY 4.0; 

Tilgjengelig fra: 2024-08-19 Laget: 2024-08-19 Sist oppdatert: 2024-11-14bibliografisk kontrollert
Sarkar, O., Antonopoulou, I., Xiros, C., Bruce, Y., Souadkia, S., Rova, U., . . . Matsakas, L. (2024). Carbonic anhydrase assisted acidogenic fermentation of forest residues for low carbon hydrogen and volatile fatty acid production: enhanced in situ CO2 reduction and microbiological analysis. Green Chemistry, 26(9), 5564-5582
Åpne denne publikasjonen i ny fane eller vindu >>Carbonic anhydrase assisted acidogenic fermentation of forest residues for low carbon hydrogen and volatile fatty acid production: enhanced in situ CO2 reduction and microbiological analysis
Vise andre…
2024 (engelsk)Inngår i: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 26, nr 9, s. 5564-5582Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Carbonic anhydrase (CA) is considered an efficient enzyme for fermentation systems exhibiting a wide range of applications, enhancing both the efficacy and output of the fermentation process. The present study aimed to evaluate the production of acidogenic biohydrogen (bioH2) and volatile fatty acids (VFA) using forest residues as a renewable feedstock. Specifically, the study examined the integration of CA derived from Desulfovibrio vulgaris into the acidogenic fermentation (AF) process. The experimental procedure involved a cascade design conducted in two distinct phases. In phase I, the concentration of CA in the AF was systematically optimized, with glucose serving as the substrate. In phase II, three influential parameters (pH, pressurization with in situ generated gas and organic load) were evaluated on AF in association with optimized CA concentration from phase I. In phase II, glucose was replaced with renewable sugars obtained from forest residues after steam explosion pretreatment followed by enzymatic saccharification. The incorporation of CA in AF was found to be beneficial in steering acidogenic metabolites. Alkaline conditions (pH 8) promoted bioH2, yielding 210.9 mLH2 gCOD−1, while introducing CA further increased output to 266.6 mLH2 gCOD−1. This enzymatic intervention improved the production of bioH2 conversion efficiency (HCE) from 45.3% to 57.2%. Pressurizing the system accelerated VFA production with complete utilization of in situ produced H2 + CO2 compared to non-pressurized systems. Particularly, caproic acid production was improved under pressurized conditions which was accomplished by the targeted enrichment of chain-elongating bacteria in the mixed culture. The microbial diversity analysis showed the dominance of Firmicutes suggesting a significant degree of adaptation to the experimental contexts, leading to an enhanced production of acidogenic metabolites.

sted, utgiver, år, opplag, sider
Royal Society of Chemistry, 2024
HSV kategori
Forskningsprogram
Biokemisk processteknik; Centrumbildning - Bio4Energy
Identifikatorer
urn:nbn:se:ltu:diva-105210 (URN)10.1039/d4gc00044g (DOI)001199919900001 ()2-s2.0-85190449731 (Scopus ID)
Merknad

Validerad;2024;Nivå 2;2024-06-28 (hanlid);

Funder: Bio4Energy (B4E3-FM-1-10);

Full text license: CC BY

Tilgjengelig fra: 2024-04-23 Laget: 2024-04-23 Sist oppdatert: 2024-06-28bibliografisk kontrollert
Sarkar, O., Rova, U., Christakopoulos, P. & Matsakas, L. (2024). Continuous biohydrogen and volatile fatty acids production from cheese whey in a tubular biofilm reactor: Substrate flow rate variations and microbial dynamics. International journal of hydrogen energy, 59, 1305-1316
Åpne denne publikasjonen i ny fane eller vindu >>Continuous biohydrogen and volatile fatty acids production from cheese whey in a tubular biofilm reactor: Substrate flow rate variations and microbial dynamics
2024 (engelsk)Inngår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 59, s. 1305-1316Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Three tubular bioreactors with a varied substrate flow rate of (2 mL/min, 5 mL/min, and 8 mL/min) were examined for 75 days. At 8 mL/min flow rate, the biohydrogen evolution was higher (3.88 mL H2/h), while its conversion efficiency was lower compared to 5 and 2 mL/min flow rate. The formation of volatile fatty acids and ammonium was also influenced by substrate flow rates. The volatile fatty acids production was slightly higher at 2 mL/min (12.74 ± 2.42 gCOD/L) and 5 mL/min (18.09 ± 2.01 gCOD/L) while, decreasing at 8 mL/min (11.85 ± 0.78 gCOD/L). Substrate flow rate significantly affected the pattern and composition of volatile fatty acids showing higher acetic acid, butyric and propionic acid production of 4.72 ± 1.46 gCOD/L (2 mL/min) 10.41 ± 0.91 gCOD/L (5 mL/min) and 1.78 ± 0.13 gCOD/L (5 mL/min). Continuous substrate input maintained the pH in the reactor due to replacement with fresh substrate, thereby controlling feedback inhibition and boosting metabolite production. Hydrogen-producing Firmicutes on the biofilm confirmed the pivotal role of the microbial community's significant contribution to converting waste to bioenergy. Overall, the present results support the use of a continuous operation mode for large-scale biohydrogen production. However, to ensure the efficacy of the system using waste or wastewater, low substrate flow rates are recommended.

sted, utgiver, år, opplag, sider
Elsevier Ltd, 2024
Emneord
Biofilm reactor, Biohydrogen, Cheese whey, Continuous mode operation, Volatile fatty acids
HSV kategori
Forskningsprogram
Biokemisk processteknik
Identifikatorer
urn:nbn:se:ltu:diva-104881 (URN)10.1016/j.ijhydene.2024.02.041 (DOI)001188002700001 ()2-s2.0-85187269273 (Scopus ID)
Merknad

Validerad;2024;Nivå 2;2024-04-05 (marisr);

Full text license: CC BY

Tilgjengelig fra: 2024-03-26 Laget: 2024-03-26 Sist oppdatert: 2024-04-05bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-0079-5950