Recombinant manganese peroxidase (rMnP) from Pichia pastoris. Part 1: Kraft pulp delignification

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Haowen Xu ◽  
Gary M. Scott ◽  
Fei Jiang ◽  
Christine Kelly
Keyword(s):  
Pichia Pastoris ◽  
Manganese Peroxidase ◽  
Lignin Content ◽  
Kappa Number ◽  
White Rot ◽  
Enzyme Treatment ◽  
High Yield ◽  
Kraft Pulps ◽  
Simultaneous Application ◽  
Peroxide Bleaching

AbstractManganese peroxidase (MnP) is the main enzyme implicated in the biobleaching of kraft pulps by white-rot fungi. However, potential commercial applications of this enzyme have been limited by its availability in large quantities. Advances have been made to produce high-yield concentrated recombinant MnP (rMnP). The objective of this study was to evaluate the ability of rMnP to delignify and brighten kraft pulps. The rMnP, produced from the yeastPichia pastoris– in high-cell density and in fed-batch fermentations – was found to be effective in lignin removal in both hardwood and softwood unbleached kraft pulps. The rMnP applied at 30 U g-1pulp for 24 h followed by alkali extraction caused significant kappa number reductions for all the pulps tested with different initial lignin contents and structures. Softwood and hardwood pulps showed similar delignification rates during rMnP treatments. Highly delignified pulps with kappa number less than 10 are less susceptible to delignification by rMnP compared with the pulps with higher lignin content. The rMnP-treated pulp was also shown to be more susceptible to subsequent peroxide bleaching compared with the control pulp. More than 60% of the kappa number reduction was achieved by sequential rMnP treatments combined with alkaline extraction. Sequential treatment with xylanase and rMnP also resulted in more extensive delignification than in each enzyme treatment alone or in the case of simultaneous application of the enzymes.

scholarly journals Pretreatment of Marasmius sp. on Biopulping of Oil Palm Empty Fruit Bunches

2015 ◽  
Vol 9 (7) ◽  
pp. 1 ◽  
Author(s):  
Hendro Risdianto ◽  
Susi Sugesty
Keyword(s):  
Oil Palm ◽  
Lignin Peroxidase ◽  
Manganese Peroxidase ◽  
Lignin Content ◽  
White Rot Fungi ◽  
Kappa Number ◽  
White Rot ◽  
Empty Fruit Bunches ◽  
Degrading Enzymes

White rot fungi have an ability to degrade lignin by employing lignin-degrading enzymes i.e Lignin Peroxidase, Manganese Peroxidase and Laccase. Therefore, the fungi can be utilized on the pretreatment of biomass in pulp making (biopulping) and biobleaching. In this study, the pretreatment using White Rot Fungi of Marasmius sp. has been conducted on the the Oil Palm Empty Fruit Bunches (EFBs). Marasmius sp. has been grown on EFBs for 30 days. The results showed that the lignin content could be removed by 35.94%. However, cellulose and hemicelluloses relatively did not show any changes in the EFBs. From the pulping process, the pretreatment exhibited the Kappa Number of 31.10. Compared to no pretreatment of white rot fungi, the Kappa Number obtained was 38.63. This result demonstrated a promising process for a green pulp making.

Deep eutectic solvent delignification: Impact of initial lignin

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 7301-7310
Author(s):  
Veronika Majová ◽  
Silvia Horanová ◽  
Andrea Škulcová ◽  
Jozef Šima ◽  
Michal Jablonský
Keyword(s):  
Lactic Acid ◽  
Oxalic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Detailed Understanding

This study aimed to resolve the issue of the lack of detailed understanding of the effect of initial lignin content in hardwood kraft pulps on pulp delignification by deep eutectic solvents. The authors used Kappa number of the concerned pulp, intrinsic viscosity, and selectivity and efficiency of delignification as the parameters of the effect. The pulp (50 g oven dry pulp) was treated with four different DESs systems based on choline chloride with lactic acid (1:9), oxalic acid (1:1), malic acid (1:1), and system alanine:lactic acid (1:9); the results were compared to those reached by oxygen delignification. The results showed that the pulp with a higher initial lignin content had a greater fraction of easily removed lignin fragments.

Fluorescence spectroscopy for chromophore studies on bleached kraft pulps

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 509-515 ◽  
Author(s):  
Sirje Liukko ◽  
Ville Tasapuro ◽  
Tiina Liitiä
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Lignin Content ◽  
Excitation Wavelength ◽  
Kraft Pulps ◽  
Carbonyl Groups ◽  
Residual Lignin ◽  
Pulp Bleaching ◽  
Peroxide Bleaching ◽  
Brightness Reversion

Abstract Fluorescence techniques are highly sensitive and, since aromatic lignin is the most likely source of natural pulp fluorescence, they are suitable for detailed investigation of residual lignin in bleached pulps. Such investigations are important to our understanding of the bleachability and brightness reversion of pulps. In this study, the effect of bleaching on pulps was evaluated using fluorescence spectra of two softwood kraft pulps bleached in six elemental chlorine-free and totally chlorine-free sequences. Fluorescence spectra were recorded in each bleaching stage using four different instrument settings. In general, pulp fluorescence at excitation wavelengths of 270 and 350 nm increased as bleaching proceeded. Below a certain lignin content, however, pulp fluorescence measured at an excitation wavelength of 430 nm decreased with the residual lignin content. Carbonyl groups have a quenching effect on fluorescence, and the formation of carbonyl groups after oxygen and ozone delignification induced a decrease in pulp fluorescence. The increase in pulp fluorescence after peroxide bleaching stages was due to the removal of carbonyl groups. Reactions of chromophores during brightness reversion also had an effect on pulp fluorescence. These findings demonstrate that fluorescence spectroscopy provides an interesting tool for pulp bleaching studies.

Effects of White-Rot Fungus Trametes Sp.lg-9 Treatment on Properties of Chlorine-Containing Bleaching Wastewater

2012 ◽  
Vol 550-553 ◽  
pp. 2241-2245
Author(s):  
Zhi Qiang Pang ◽  
Chao Yang ◽  
Jia Chuan Chen ◽  
Gui Hua Yang
Keyword(s):  
Ph Value ◽  
Lignin Content ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Crude Enzyme ◽  
White Rot ◽  
Enzyme Treatment ◽  
White Rot Fungus ◽  
Short Time ◽  
Low Dosage

Effects of white-rot fungus Trametes sp.lg-9 treatment on properties of chlorine-containing bleaching wastewater were investigated. Trametes sp.lg-9 was cultured in chlorine-containing bleaching wastewater under optimal growth conditions, COD sharply decreased from 10740mg/l to 7811mg/l after 5 days; chroma firstly increased from 6212 degree to 7272 degree at 5 days and then declined to 5303 degree; lignin content firstly increased to 0.33 g/l and then decreased to 0.323 g/l. Separating the crude enzyme solution to treat chlorine-containing bleaching wastewater, demonstrating the suitable temperature of the crude enzyme treatment is 40 °C and the optimum pH value is 5.6. COD, chroma and lignin content of chlorine-containing bleaching wastewater can be significantly reduced by crude enzyme treatment on conditions of low dosage and short time.

Recombinant manganese peroxidase (rMnP) from Pichia pastoris. Part 2: Application in TCF and ECF bleaching

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Haowen Xu ◽  
Gary M. Scott ◽  
Fei Jiang ◽  
Christine Kelly
Keyword(s):  
Pichia Pastoris ◽  
Manganese Peroxidase ◽  
Kraft Pulp ◽  
Energy Savings ◽  
Strength Properties ◽  
Enzymatic Treatment ◽  
Peroxide Bleaching ◽  
Alkaline Peroxide ◽  
Elemental Chlorine ◽  
Ecf Bleaching

AbstractThe recombinant manganese peroxidase (rMnP) produced from the yeastPichia pastorishas been investigated in totally chlorine free (TCF) and elemental chlorine free (ECF) bleaching sequences for improving the bleachability of kraft pulps. In TCF bleaching, oxygen delignified hardwood kraft pulp was treated with rMnP, followed by a sequence combining a chelating and alkaline peroxide bleaching stage. The inclusion of the enzymatic treatment significantly improved the pulp brightness to a level that is difficult to obtain by chemical bleaching alone. Furthermore, the treatment with rMnP resulted in energy savings during pulp refining with PFI mill with a slight improvement in pulp strength properties such as tensile index and burst index. In ECF bleaching, a significant reduction in chlorine dioxide consumption was obtained. A three-stage rMnP treatment combined with alkaline extraction, followed by DED bleaching sequence for hardwood kraft pulp (HWKP) or DEDED bleaching sequence for softwood kraft pulp (SWKP), reduced the total effective chlorine by 41% and 32% for HWKP and SWKP, respectively, compared with the conventional bleaching sequences without enzymatic treatment. The strength properties of the enzyme-treated pulp were also slightly better than that of the control pulp. Further reductions in the consumption of total effective chlorine were obtained when a xylanase pretreatment was incorporated into the bleaching sequence before the repeated rMnP treatment.

Improving paper wet strength via increased lignin content and hot-pressing temperature

TAPPI Journal ◽  
2020 ◽  
Vol 19 (10) ◽  
pp. 487-497
Author(s):  
TOVE JOELSSON ◽  
GUNILLA PETTERSSON ◽  
SVEN NORGREN ◽  
ANNA SVEDBERG ◽  
HANS HOGLUND ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Lignin Content ◽  
Pilot Scale ◽  
Strength Properties ◽  
High Yield ◽  
Kraft Pulps ◽  
Pressing Temperature ◽  
Wet Strength ◽  
Tensile Index ◽  
Reference Samples

It is known that the strength properties of wood-based paper materials can be enhanced via hot-pressing techniques. Today, there is a desire not only for a change from fossil-based packaging materials to new sustainable bio-based materials, but also for more effective and eco-friendly solutions for improving the dry and wet strength of paper and board. Against this background, hot pressing of paper made from high yield pulp (HYP), rich in lignin, becomes highly interesting. This study investigated the influence of pressing temperature and native lignin content on the properties of paper produced by means of hot pressing. Kraft pulps of varied lignin content (kappa numbers: 25, 50, 80) were produced at pilot scale from the same batch by varying the cooking time. We then studied the effect of lignin content by evaluating the physical properties of Rapid Köthen sheets after hot pressing in the temperature range of 20°C–200°C with a constant nip pressure of 7 MPa. The pilot-scale cooked pulps were compared with reference samples of mill-produced northern bleached soft-wood kraft (NBSK) pulp and mill-produced chemithermomechanical pulp (CTMP). Generally, the results demonstrated that lignin content had a significant effect on both dry and wet tensile index. All of the pilot cooked pulps with increased lignin content had a higher tensile index than the reference NBSK pulp. To obtain high tensile index, both dry and wet, the pressing temperature should be set high, preferably at least 200°C; that is, well above the glass transition temperature (Tg) for lignin. Moreover, the lignin content should preferably also be high. All kraft pulps investigated in this study showed a linear relationship between wet strength and lignin content.

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 49-53 ◽  
Author(s):  
CHRISTINE CHIRAT ◽  
LUCIE BOIRON ◽  
DOMINIQUE LACHENAL
Keyword(s):  
Carbon Content ◽  
Acid Hydrolysis ◽  
13C Nmr ◽  
Kraft Lignin ◽  
Kappa Number ◽  
Hydroxyl Groups ◽  
Kraft Pulps ◽  
Quaternary Carbon ◽  
Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

Does the kappa number method accurately reflect lignin content in nonwood pulps?

TAPPI Journal ◽  
2018 ◽  
Vol 17 (11) ◽  
pp. 611-617
Author(s):  
Sabrina Burkhardt
Keyword(s):  
Lignin Content ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Original Data ◽  
Kappa Number ◽  
Klason Lignin ◽  
Organic Functional Groups ◽  
Pulp Properties ◽  
Wood Pulps ◽  
Hexenuronic Acid

The traditional kappa number method was developed in 1960 as a way to more quickly determine the level of lignin remaining in a completed or in-progress pulp. A significantly faster approach than the Klason lignin procedure, the kappa number method is based on the reaction of a strong oxidizing agent (KMnO4) with lignin and small amounts of other organic functional groups present in the pulp, such as hexenuronic acid. While the usefulness of the kappa number for providing information about bleaching requirements and pulp properties has arguably transformed the pulp and paper industry, it has been mostly developed for kraft, sulfite, and soda wood pulps. Nonwood species have a different chemical makeup than hardwood or softwood sources. These chemical differ-ences can influence kappa and Klason measurements on the pulp and lead to wide ranges of error. Both original data from Sustainable Fiber Technologies’ sulfur and chlorine-free pulping process and kappa and Klason data from various nonwood pulp literature sources will be presented to challenge the assumption that the kappa number accurately represents lignin content in nonwood pulps.

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