Biobleaching chemistry of laccase-mediator systems on high-lignin-content kraft pulps

Chakar, Fadi S.; Ragauskas, Arthur J.
February 2004
Canadian Journal of Chemistry;Feb2004, Vol. 82 Issue 2, p344
Academic Journal
A high-lignin-content softwood kraft pulp was reacted with laccase in the presence of 1-hydroxybenzotriazole (HBT), N-acetyl-N-phenylhydroxylamine (NHA), and violuric acid (VA). The biodelignification response with violuric acid was superior to both 1-hydroxybenzotriazole and N-acetyl-N-phenylhydroxylamine. NMR analysis of residual lignins isolated before and after the biobleaching treatments revealed that the latter material was highly oxidized and that the magnitude of structural changes was most pronounced with the laccase – violuric acid biobleaching system. An increase in the content of carboxylic acid groups and a decrease in methoxyl groups were noted with all three laccase-mediator systems. The oxidation biobleaching pathway is directed primarily towards noncondensed C5 phenolic lignin functional structures for all three laccase-mediated systems. The laccase – violuric acid system was also reactive towards C5-condensed phenolic lignin structures.


Related Articles

  • Synthesis of esters ofm-C(7)-iso-propylcarboran-C(1)-carboxylic acid, natural terpene alcohols, and plant phenols. Dikusar, E.A.; Kozlov, N.G.; Zvereva, T.D.; Yuvchenko, A.P.; Mel'nichuk, L.A. // Chemistry of Natural Compounds;Sep2004, Vol. 40 Issue 5, p472 

    Previously undescribed esters1b-21bwere prepared by reaction of cetyl alcohol1a, terpene alcohols2a-16a, plant phenols17a-19a, and alcohols20aand21awith m-C(7)-iso-propylcarboran-C(1)-carboxylic acid.

  • Enzymatic modification of kraft lignin through oxidative coupling with water-soluble phenols. Lund, M.; Ragauskas, A. J. // Applied Microbiology & Biotechnology;Jun2001, Vol. 55 Issue 6, p699 

    The aromatic polymer lignin can be modified through promotion of oxidative coupling between phenolic groups on lignin and various phenols. The reaction is initiated by an oxidation of both components, e.g., by using the oxidoreductases laccase or peroxidase. Coupling between phenolic monomers...

  • One-Pot Synthesis of Aromatic Hydroxyketones under Microwave Irradiation and Solvent-Free Conditions. Yuqing Cao; Fangrui Song; Liya Xu; Dingxiang Du; Xiaojun Yang; Xiangtao Xu // International Journal of Chemistry;Feb2011, Vol. 3 Issue 1, p123 

    An efficient one-pot synthesis of aromatic hydroxyketones with carboxylic acids as acylating agents without solvent under microwave irradiation was reported. The reaction time was only 1-5 mm. Besides, this method has a feature of high yields, low cost, easy manipulation and less pollution.

  • Role of carboxylic and phenolic groups in NOM adsorption on minerals: a review. Guan, X. H.; Li, D. L.; Shang, C.; Chen, G. H. // Water Science & Technology: Water Supply;2006, Vol. 6 Issue 6, p155 

    This paper presented the current state of our understanding of the roles of carboxylic and phenolic groups in NOM adsorption and reviewed the contradictory opinions in the literatures. Previous studies carried out by other researchers indicated that aromatic carboxylates were adsorbed onto metal...

  • Benzoic Acid March 21, 2005.  // Chemical Market Reporter;3/21/2005, Vol. 267 Issue 12, p23 

    The article presents information on production of benzoic acid. Benzoic acid, crystalline white solid, is produced commercially by partial oxidation of toluene. Most benzoic acid is consumed captively in the production of a variety of industrial chemicals. It is estimated that 105 million pounds...

  • Potential inhibitors from wet oxidation of wheat straw and their effect on growth and ethanol production by Thermoanaerobacter mathranii. Klinke, H. B.; Thomsen, A. B.; Ahring, B. K. // Applied Microbiology & Biotechnology;Dec2001, Vol. 57 Issue 5/6, p631 

    Alkaline wet oxidation (WO) (using water, 6.5 g/l sodium carbonate, and 12 bar oxygen at 195 °C) was used for pre-treating wheat straw (60 g/l), resulting in a hemicellulose-rich hydrolysate and a cellulose-rich solid fraction. The hydrolysate consisted of soluble hemicellulose (9 g/l),...

  • Acid Activated Indian Bentonite, an Efficient Catalyst for Esterification of Carboxylic Acids. Vijayakumar, B.; Nagendrappa, Gopalpur; Jai Prakash, B. // Catalysis Letters;Mar2009, Vol. 128 Issue 1/2, p183 

    The preparation, characterization, and catalytic properties of acid activated Indian bentonite (AAIB) are reported. AAIB has been characterized by XRD (basal spacing, 15.05 Ã…), specific surface area (273 m2/g), pore volume and pore diameter using BET method, TGA, SEM, and surface acidity by...

  • Enhanced stability of laccase in the presence of phenolic compounds. Mai, C.; Schormann, W.; Milstein, O.; Hüttermann, A. // Applied Microbiology & Biotechnology;Oct2000, Vol. 54 Issue 4, p510 

    The storage stability of laccase (EC from the white-rot basidomycete Trametes versicolor in potassium-citrate buffer was enhanced by various phenolic compounds as well as by lignin sulfonate. The highest storage stability was obtained with phenolics, e.g. phloroglucin and...

  • Wet oxidation of lignin model compounds and acetic acid production. Suzuki, H.; Cao, J.; Jin, F.; Kishita, A.; Enomoto, H.; Moriya, T. // Journal of Materials Science;Mar2006, Vol. 41 Issue 5, p1591 

    To investigate the wet oxidation (WO) pathways of acetic acid production from lignin, 2-methoxyphenol, 2,6-dimethoxyphenol, and phenol, as lignin model compounds were oxidized in a batch reactor at a temperature of 300°C, residence times of 10–60 seconds and oxygen supplies of...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics