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Winestrand, Sandra
Publikasjoner (10 av 13) Visa alla publikasjoner
Wang, Z., Winestrand, S., Gillgren, T. & Jönsson, L. J. (2018). Chemical and structural factors influencing enzymatic saccharification of wood from aspen, birch and spruce. Biomass and Bioenergy, 109, 125-134
Åpne denne publikasjonen i ny fane eller vindu >>Chemical and structural factors influencing enzymatic saccharification of wood from aspen, birch and spruce
2018 (engelsk)Inngår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 109, s. 125-134Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The susceptibility of untreated and sulfuric-acid-pretreated aspen, birch, and spruce to analytical enzymatic saccharification was studied in relation to their chemical composition and physical-structural features. The analytical data collected covered the mass fractions of lignin, carbohydrates, and extractives, the release of acetic acid, formic acid, and uronic acids by acid and alkaline hydrolysis, crystallinity and crystallite size, syringyl: guaiacyl (S:G) ratio of lignin, cellulose accessibility, FTIR spectra, images from SEM and fluorescence microscopy, and susceptibility to enzymatic saccharification using enzyme mixtures with and without supplementary xylanase.In the absence of pretreatment the mass fraction yield of Glc on the original dry wood in the analytical enzymatic saccharification increased in the order birch (16 g kg−1) < spruce (35 g kg−1) < aspen (150 g kg−1). After acid pretreatment, the order changed to spruce (170 g kg−1) < aspen (290 g kg−1), birch (290 g kg−1). The relatively high recalcitrance of untreated birch was not possible to relate to mass fraction of lignin, S:G ratio, cellulose crystallinity, or mass fraction of acetyl, but rather to structural features, such as a more compact surface structure with high density and low cellulose accessibility. The relatively high sugar yields from both untreated and pretreated aspen suggest that aspen wood is well suited as feedstock for production of liquid biofuels and green chemicals in forest-based biorefineries.

sted, utgiver, år, opplag, sider
Elsevier, 2018
Emneord
Hardwood, Softwood, Chemical composition, Dilute-acid pretreatment, Enzymatic saccharification, Physical structure
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-143889 (URN)10.1016/j.biombioe.2017.12.020 (DOI)000424939200015 ()
Prosjekter
Bio4Energy
Tilgjengelig fra: 2018-01-12 Laget: 2018-01-12 Sist oppdatert: 2019-08-30bibliografisk kontrollert
Ratke, C., Terebieniec, B. K., Winestrand, S., Derba-Maceluch, M., Grahn, T., Schiffthaler, B., . . . Mellerowicz, E. J. (2018). Downregulating aspen xylan biosynthetic GT43 genes in developing wood stimulates growth via reprograming of the transcriptome. New Phytologist, 219(1), 230-245
Åpne denne publikasjonen i ny fane eller vindu >>Downregulating aspen xylan biosynthetic GT43 genes in developing wood stimulates growth via reprograming of the transcriptome
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2018 (engelsk)Inngår i: New Phytologist, ISSN 0028-646X, Vol. 219, nr 1, s. 230-245Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Xylan is one of the main compounds determining wood properties in hardwood species. The xylan backbone is thought to be synthesized by a synthase complex comprising two members of the GT43 family. We downregulated all GT43 genes in hybrid aspen (Populus tremulaxtremuloides) to understand their involvement in xylan biosynthesis.

All three clades of the GT43 family were targeted for downregulation using RNA interference individually or in different combinations, either constitutively or specifically in developing wood.

Simultaneous downregulation in developing wood of the B (IRX9) and C (IRX14) clades resulted in reduced xylan Xyl content relative to reducing end sequence, supporting their role in xylan backbone biosynthesis. This was accompanied by a higher lignocellulose saccharification efficiency. Unexpectedly, GT43 suppression in developing wood led to an overall growth stimulation, xylem cell wall thinning and a shift in cellulose orientation. Transcriptome profiling of these transgenic lines indicated that cell cycling was stimulated and secondary wall biosynthesis was repressed. We suggest that the reduced xylan elongation is sensed by the cell wall integrity surveying mechanism in developing wood.

Our results show that wood-specific suppression of xylan-biosynthetic GT43 genes activates signaling responses, leading to increased growth and improved lignocellulose saccharification.

Emneord
cellulose microfibril angle, GT43, Populus, saccharification, secondary wall, wood development, xylan biosynthesis
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-150384 (URN)10.1111/nph.15160 (DOI)000434153200026 ()29708593 (PubMedID)2-s2.0-85046148362 (Scopus ID)
Prosjekter
Bio4Energy
Tilgjengelig fra: 2018-08-06 Laget: 2018-08-06 Sist oppdatert: 2019-08-30bibliografisk kontrollert
Wang, Z., Gräsvik, J., Jönsson, L. J. & Winestrand, S. (2017). Comparison of [HSO4](-), [Cl](-) and [MeCO2](-) as anions in pretreatment of aspen and spruce with imidazolium-based ionic liquids. BMC Biotechnology, 17, Article ID 82.
Åpne denne publikasjonen i ny fane eller vindu >>Comparison of [HSO4](-), [Cl](-) and [MeCO2](-) as anions in pretreatment of aspen and spruce with imidazolium-based ionic liquids
2017 (engelsk)Inngår i: BMC Biotechnology, ISSN 1472-6750, E-ISSN 1472-6750, Vol. 17, artikkel-id 82Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background: Ionic liquids (ILs) draw attention as green solvents for pretreatment of lignocellulose before enzymatic saccharification. Imidazolium-based ILs with different anionic constituents ([HSO4], [Cl], [MeCO2]) were compared with regard to pretreatment of wood from aspen and spruce. The objective was to elucidate how the choice of anionic constituent affected the suitability of using the IL for pretreatment of hardwood, such as aspen, and softwood, such as spruce. The investigation covered a thorough analysis of the mass balance of the IL pretreatments, the effects of pretreatment on the cell wall structure as assessed by fluorescence microscopy, and the effects of pretreatment on the susceptibility to enzymatic saccharification. Torrefied aspen and spruce were included in the comparison for assessing how shifting contents of hemicelluloses and Klason lignin affected the susceptibility of the wood to IL pretreatment and enzymatic saccharification.

Results: The glucose yield after IL pretreatment increased in the order [Cl] < [HSO4] < [MeCO2] for aspen, but in the order [HSO4] < [Cl] < [MeCO2] for spruce. For both aspen and spruce, removal of hemicelluloses and lignin increased in the order [Cl] < [MeCO2] < [HSO4]. Fluorescence microscopy indicated increasingly disordered cell wall structure following the order [HSO4] < [Cl] < [MeCO2]. Torrefaction of aspen converted xylan to pseudo-lignin and changed the glucose yield order to [HSO4] < [Cl] < [MeCO2].

Conclusions: The acidity of [HSO4] caused extensive hydrolysis of xylan, which facilitated pretreatment of xylan-rich hardwood. Apart from that, the degree of removal of hemicelluloses and lignin did not correspond well with the improvement of the enzymatic saccharification. Taken together, the saccharification results were found to mainly reflect (i) the different capacities of the ILs to disorder the cell wall structure, (ii) the recalcitrance caused by high xylan content, and (iii) the capacity of the [HSO4]-based IL to hydrolyze xylan.

sted, utgiver, år, opplag, sider
BioMed Central, 2017
Emneord
Hardwood, Softwood, Pretreatment, Ionic liquid, Enzymatic saccharification, Torrefaction, Xylan, ason lignin, Pseudo-lignin
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-142457 (URN)10.1186/s12896-017-0403-0 (DOI)000415149600001 ()29141617 (PubMedID)
Prosjekter
Bio4Energy
Tilgjengelig fra: 2017-12-04 Laget: 2017-12-04 Sist oppdatert: 2019-08-30bibliografisk kontrollert
Normark, M., Pommer, L., Gräsvik, J., Hedenström, M., Gorzsas, A., Winestrand, S. & Jönsson, L. J. (2016). Biochemical Conversion of Torrefied Norway Spruce After Pretreatment with Acid or Ionic Liquid. Bioenergy Research, 9(1), 355-368
Åpne denne publikasjonen i ny fane eller vindu >>Biochemical Conversion of Torrefied Norway Spruce After Pretreatment with Acid or Ionic Liquid
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2016 (engelsk)Inngår i: Bioenergy Research, ISSN 1939-1234, E-ISSN 1939-1242, Vol. 9, nr 1, s. 355-368Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The chemical effects of torrefaction and the possibility to combine torrefaction with biochemical conversion were explored in experiments with five preparations of wood of Norway spruce that had been torrefied using different degrees of severity. Compositional analysis and analyses using solid-state CP/MAS C-13 NMR, Fourier-transform infrared (FTIR) spectroscopy, and Py-GC/MS showed small gradual changes, such as decreased hemicellulosic content and increased Klason lignin value, for torrefaction conditions in the range from 260 A degrees C and 8 min up to 310 A degrees C and 8 min. The most severe torrefaction conditions (310 A degrees C, 25 min) resulted in substantial loss of glucan and further increase of the Klason lignin value, which was attributed to conversion of carbohydrate to pseudo-lignin. Even mild torrefaction conditions led to decreased susceptibility to enzymatic hydrolysis of cellulose, a state which was not changed by pretreatment with sulfuric acid. Pretreatment with the ionic liquid (IL) 1-butyl-3-methylimidazolium acetate overcame the additional recalcitrance caused by torrefaction, and the glucose yields after 72 h of enzymatic hydrolysis of wood torrefied at 260 A degrees C for 8 min and at 285 A degrees C for 16.5 min were as high as that of IL-pretreated non-torrefied spruce wood. Compared to IL-pretreated non-torrefied reference wood, the glucose production rates after 2 h of enzymatic hydrolysis of IL-pretreated wood torrefied at 260 A degrees C for 8 min and at 285 A degrees C for 16.5 min were 63 and 40 % higher, respectively. The findings offer increased understanding of the effects of torrefaction and indicate that mild torrefaction is compatible with biochemical conversion after pretreatment with alternative solvents that disrupt pseudo-lignin-containing lignocellulose.

Emneord
Torrefaction, Wood, Acid pretreatment, Ionic liquid, Enzymatic hydrolysis
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-118386 (URN)10.1007/s12155-015-9698-7 (DOI)000370816300032 ()
Prosjekter
Bio4Energy
Tilgjengelig fra: 2016-04-22 Laget: 2016-03-18 Sist oppdatert: 2019-08-30bibliografisk kontrollert
Normark, M., Winestrand, S., Lestander, T. A. & Jönsson, L. J. (2014). Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine. BMC Biotechnology, 14, Article ID 20.
Åpne denne publikasjonen i ny fane eller vindu >>Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine
2014 (engelsk)Inngår i: BMC Biotechnology, ISSN 1472-6750, E-ISSN 1472-6750, Vol. 14, artikkel-id 20Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background: Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification. Results: All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification. Conclusions: Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass.

sted, utgiver, år, opplag, sider
BioMed Central, 2014
Emneord
Scots pine, Chemical composition, Dilute-acid pretreatment, Enzymatic saccharification
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-89235 (URN)10.1186/1472-6750-14-20 (DOI)000334881900001 ()
Tilgjengelig fra: 2014-05-26 Laget: 2014-05-26 Sist oppdatert: 2018-06-07bibliografisk kontrollert
Johansson, K., Gillgren, T., Winestrand, S., Jarnstrom, L. & Jönsson, L. (2014). Comparison of lignin derivatives as substrates for laccase-catalyzed scavenging of oxygen in coatings and films. Journal of Biological Engineering, 8(1)
Åpne denne publikasjonen i ny fane eller vindu >>Comparison of lignin derivatives as substrates for laccase-catalyzed scavenging of oxygen in coatings and films
Vise andre…
2014 (engelsk)Inngår i: Journal of Biological Engineering, ISSN 1754-1611, E-ISSN 1754-1611, Vol. 8, nr 1Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background:

Lignin derivatives are phenylpropanoid biopolymers derived from pulping and biorefinery processes. The possibility to utilize lignin derivatives from different types of processes in advanced enzyme-catalyzed oxygen-scavenging systems intended for active packaging was explored. Laccase-catalyzed oxidation of alkali lignin (LA), hydrolytic lignin (LH), organosolv lignin (LO), and lignosulfonates (LS) was compared using oxygen-scavenging coatings and films in liquid and gas phase systems.

Results:

When coatings containing lignin derivatives and laccase were immersed in a buffered aqueous solution, the oxygen-scavenging capability increased in the order LO < LH < LA < LS. Experiments with coatings containing laccase and LO, LH or LA incubated in oxygen-containing gas in air-tight chambers and at a relative humidity (RH) of 100% showed that paperboard coated with LO and laccase reduced the oxygen content from 1.0% to 0.4% during a four-day period, which was far better than the results obtained with LA or LH. LO-containing coatings incubated at 92% RH also displayed activity, with a decrease in oxygen from 1.0% to 0.7% during a four-day period. The oxygen scavenging was not related to the content of free phenolic hydroxyl groups, which increased in the order LO < LS < LH < LA. LO and LS were selected for further studies and films containing starch, clay, glycerol, laccase and LO or LS were characterized using gel permeation chromatograpy, dynamic mechanical analysis, and wet stability.

Conclusions:

The investigation shows that different lignin derivatives exhibit widely different properties as a part of active coatings and films. Results indicate that LS and LO were most suitable for the application studied and differences between them were attributed to a higher degree of laccase-catalyzed cross-linking of LS than of LO. Inclusion in active-packaging systems offers a new way to utilize some types of lignin derivatives from biorefining processes.

Emneord
Lignin derivatives, Laccase, Coating, Film, Oxygen scavenger
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-90798 (URN)10.1186/1754-1611-8-1 (DOI)000335792000001 ()
Tilgjengelig fra: 2014-10-09 Laget: 2014-07-01 Sist oppdatert: 2018-06-07bibliografisk kontrollert
Zhang, S., Winestrand, S., Guo, X., Chen, L., Hong, F. & Jönsson, L. (2014). Effects of aromatic compounds on the production of bacterial nanocellulose by Gluconacetobacter xylinus. Microbial Cell Factories, 13, 62
Åpne denne publikasjonen i ny fane eller vindu >>Effects of aromatic compounds on the production of bacterial nanocellulose by Gluconacetobacter xylinus
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2014 (engelsk)Inngår i: Microbial Cell Factories, ISSN 1475-2859, E-ISSN 1475-2859, Vol. 13, s. 62-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background:

Bacterial cellulose (BC) is a polymeric nanostructured fibrillar network produced by certain microorganisms, principally Gluconacetobacter xylinus. BC has a great potential of application in many fields. Lignocellulosic biomass has been investigated as a cost-effective feedstock for BC production through pretreatment and hydrolysis. It is well known that detoxification of lignocellulosic hydrolysates may be required to achieve efficient production of BC. Recent results suggest that phenolic compounds contribute to the inhibition of G. xylinus. However, very little is known about the effect on G. xylinus of specific lignocellulose-derived inhibitors. In this study, the inhibitory effects of four phenolic model compounds (coniferyl aldehyde, ferulic acid, vanillin and 4-hydroxybenzoic acid) on the growth of G. xylinus, the pH of the culture medium, and the production of BC were investigated in detail. The stability of the phenolics in the bacterial cultures was investigated and the main bioconversion products were identified and quantified.

Results:

Coniferyl aldehyde was the most potent inhibitor, followed by vanillin, ferulic acid, and 4-hydroxybenzoic acid. There was no BC produced even with coniferyl aldehyde concentrations as low as 2 mM. Vanillin displayed a negative effect on the bacteria and when the vanillin concentration was raised to 2.5 mM the volumetric yield of BC decreased to similar to 40% of that obtained in control medium without inhibitors. The phenolic acids, ferulic acid and 4-hydroxybenzoic acid, showed almost no toxic effects when less than 2.5 mM. The bacterial cultures oxidized coniferyl aldehyde to ferulic acid with a yield of up to 81%. Vanillin was reduced to vanillyl alcohol with a yield of up to 80%.

Conclusions:

This is the first investigation of the effect of specific phenolics on the production of BC by G. xylinus, and is also the first demonstration of the ability of G. xylinus to convert phenolic compounds. This study gives a better understanding of how phenolic compounds and G. xylinus cultures are affected by each other. Investigations in this area are useful for elucidating the mechanism behind inhibition of G. xylinus in lignocellulosic hydrolysates and for understanding how production of BC using lignocellulosic feedstocks can be performed in an efficient way.

Emneord
Gluconacetobacter xylinus, Phenolic compound, Bacterial cellulose, Inhibitor
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-90789 (URN)10.1186/1475-2859-13-62 (DOI)000335997200001 ()
Tilgjengelig fra: 2014-10-09 Laget: 2014-07-01 Sist oppdatert: 2018-06-07bibliografisk kontrollert
Gräsvik, J., Winestrand, S., Normark, M., Jönsson, L. & Mikkola, J.-P. (2014). Evaluation of four ionic liquids for pretreatment of lignocellulosic biomass.. BMC Biotechnology, 14(1), 34-45
Åpne denne publikasjonen i ny fane eller vindu >>Evaluation of four ionic liquids for pretreatment of lignocellulosic biomass.
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2014 (engelsk)Inngår i: BMC Biotechnology, ISSN 1472-6750, E-ISSN 1472-6750, Vol. 14, nr 1, s. 34-45Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

BACKGROUND: Lignocellulosic biomass is highly recalcitrant and various pretreatment techniques are needed to facilitate its effective enzymatic hydrolysis to produce sugars for further conversion to bio-based chemicals. Ionic liquids (ILs) are of interest in pretreatment because of their potential to dissolve lignocellulosic materials including crystalline cellulose.

RESULTS: Four imidazolium-based ionic liquids (ILs) ([C=C2C1im][MeCO2], [C4C1im][MeCO2], [C4C1im][Cl], and [C4C1im][HSO4]) well known for their capability to dissolve lignocellulosic species were synthesized and then used for pretreatment of substrates prior to enzymatic hydrolysis. In order to achieve a broad evaluation, seven cellulosic, hemicellulosic and lignocellulosic substrates, crystalline as well as amorphous, were selected. The lignocellulosic substrates included hybrid aspen and Norway spruce. The monosaccharides in the enzymatic hydrolysate were determined using high-performance anion-exchange chromatography. The best results, as judged by the saccharification efficiency, were achieved with [C4C1im][Cl] for cellulosic substrates and with the acetate-based ILs for hybrid aspen and Norway spruce. After pretreatment with acetate-based ILs, the conversion to glucose of glucan in recalcitrant softwood lignocellulose reached similar levels as obtained with pure crystalline and amorphous cellulosic substrates. IL pretreatment of lignocellulose resulted in sugar yields comparable with that obtained with acidic pretreatment. Heterogeneous dissolution with [C4C1im][HSO4] gave promising results with aspen, the less recalcitrant of the two types of lignocellulose included in the investigation.

CONCLUSIONS: The ability of ILs to dissolve lignocellulosic biomass under gentle conditions and with little or no by-product formation contributes to making them highly interesting alternatives for pretreatment in processes where high product yields are of critical importance.

sted, utgiver, år, opplag, sider
Springer, 2014
Emneord
Ionic liquid, Pretreatment, Lignocellulose, Enzymatic saccharification
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-90622 (URN)10.1186/1472-6750-14-34 (DOI)000335990000001 ()24779378 (PubMedID)
Tilgjengelig fra: 2014-06-26 Laget: 2014-06-25 Sist oppdatert: 2018-06-07bibliografisk kontrollert
Zhang, S., Winestrand, S., Chen, L., Li, D., Jönsson, L. & Hong, F. (2014). Tolerance of the Nanocellulose-Producing Bacterium Gluconacetobacter xylinus to Lignocellulose-Derived Acids and Aldehydes. Journal of Agricultural and Food Chemistry, 62(40), 9792-9799
Åpne denne publikasjonen i ny fane eller vindu >>Tolerance of the Nanocellulose-Producing Bacterium Gluconacetobacter xylinus to Lignocellulose-Derived Acids and Aldehydes
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2014 (engelsk)Inngår i: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, E-ISSN 1520-5118, Vol. 62, nr 40, s. 9792-9799Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Lignocellulosic biomass serves as a potential alternative feedstock for production of bacterial nanocellulose (BNC), a high-value added product of bacteria such as Gluconacetobacter xylinus. The tolerance of G. xylinus to lignocellulose derived inhibitors (formic acid, acetic acid, levulinic acid, furfural, and S-hydroxymethylfurfural) was investigated. Whereas 100 mM formic acid completely suppressed the metabolism of G xylinus, 250 mM of either acetic acid or levulinic acid still allowed glucose metabolism and BNC production to occur. Complete suppression of glucose utilization and BNC production was observed after inclusion of 20 and 30 mM furfural and 5-hydroxymethylfurfural, respectively. The highest yields observed were 88% for furoic acid/furfural and 76% for 5-hydroxymethyl-2-furoic acid/5-hydroxymethylfurfural. These results are the first demonstration of the capability of G. xylinus to tolerate lignocellulose derived inhibitors and to convert furan aldehydes.

Emneord
Gluconacetobacter xylinus, bacterial nanocellulose, lignocellulose, aliphatic acids, furan aldehydes, otransformation
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-96610 (URN)10.1021/jf502623s (DOI)000343016200021 ()
Tilgjengelig fra: 2014-11-28 Laget: 2014-11-24 Sist oppdatert: 2018-06-07bibliografisk kontrollert
Winestrand, S., Johansson, K., Järnström, L. & Jönsson, L. J. (2013). Co-immobilization of oxalate oxidase and catalase in films for scavenging of oxygen or oxalic acid. Biochemical engineering journal, 72, 96-101
Åpne denne publikasjonen i ny fane eller vindu >>Co-immobilization of oxalate oxidase and catalase in films for scavenging of oxygen or oxalic acid
2013 (engelsk)Inngår i: Biochemical engineering journal, ISSN 1369-703X, E-ISSN 1873-295X, Vol. 72, s. 96-101Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Oxalate oxidase has potential to act as an oxygen scavenger in active packaging to increase the shelf-life of food and beverages, while simultaneously producing the protective packaging gas carbon dioxide. This study shows that oxalate oxidase from barley can be immobilized with retained catalytic activity through entrapment in a latex polymer matrix. Conditions for formation of film containing oxalate oxidase have been evaluated as well as effects of storage and latex on enzyme activity, migration of enzyme in films, and the ability of the latex films to resist higher temperatures. Drying of enzyme-containing latex films at 75 °C prior to conditioning at 30 °C resulted in higher activity than drying solely at 30 °C, or drying at 95 °C or 105 °C followed by conditioning at 30 °C. Storage of films in air at 4 °C for 14 days did not negatively affect the enzymatic activity. Inclusion of catalase in films with oxalate oxidase effectively prevented release of hydrogen peroxide. The results suggest that the immobilized enzyme can successfully be used both as an oxygen scavenger and as an oxalic-acid scavenger.

sted, utgiver, år, opplag, sider
Elsevier, 2013
Emneord
Oxalate oxidase, Active packaging, Oxygen scavenger, Oxalic acid, Latex, Entrapment
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-67827 (URN)10.1016/j.bej.2013.01.006 (DOI)000319373200014 ()
Tilgjengelig fra: 2013-04-03 Laget: 2013-04-03 Sist oppdatert: 2018-06-08bibliografisk kontrollert
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