• Title/Summary/Keyword: 과산화 리그닌

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Use and Evaluation of Lignin as Ion Exchangers (이온교환체로서 리그닌의 이용과 평가)

  • Ads, Essam.N.;Nada, A.M.A.;El-Masry, A.M.
    • Journal of the Korean Chemical Society
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    • v.55 no.1
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    • pp.86-91
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    • 2011
  • Modified lignins were prepared. Soda and peroxy lignins were precipitated from black liquor produced from bagasse pulping with soda and peroxyacid pulping process. The precipitated lignins were hydrolyzed using 10% HCl. Different functional groups were also incorporated into lignin by carboxylation and phosphorylation reactions. Moreover crosslinking of these lignins were carried out using epichlorohydrin. Characterization of the modified lignins and lignins derivative were carried out using Infrared spectroscopy. Thermal analysis of these compounds were also carried out using TGA and DTA techniques. Efficiency of sorption of metal ions by the modified lignin was also investigated. It was found that, the peroxylignin and its derivatives show higher efficiency toward metal ions uptake than the soda lignin.

Effect of Hydrogen Peroxide on Pretreatment of Oakwood in a Percolation Process (Percolation 공정에서 참나무의 전처리에 과산화수소가 미치는 영향)

  • 하석중;김성배;박순철
    • KSBB Journal
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    • v.14 no.3
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    • pp.358-364
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    • 1999
  • The effect of hydrogen peroxide on pretreatment of oakwood was investigated. Reaction temperature was $170^{\circ}C$ and reaction solutions used in pretreatment were aqueous ammonia, sulfuric acid and pure water. When 10% ammonia solution was used, the extents of delignification and hemicellulose recovery were 55% and 26%, respectively. These values were significantly higher as delinigfication and lower as hemicellulose recovery than those of acid hydrolysis. To overcome this problem, hydrogen peroxide was added into ammonia solution stream to increase hemicellulose recovery. But delignification and hemicellulose recovery were not increased as much as hydrogen peroxide loading was increased. And as hydrogen peroxide loading was increased, the decomposition of sugars solubilized from hemicellulose and cellulose were increased. So there were significant differences between the total amount in solid residue and liquid hydrolyzate, and the total amount in the original biomass. It was found that hydrogen peroxide added was reacted with substrate packed mostly in the front part of reactor. In order to increase hemicellulose recovery, it was necessary to treat with acidic solution than with alkali solution. Effect of hydrogen peroxide was higher in water than acid solution.

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Purification and characterization of versatile peroxidase from Pleurotus ostreatus produced in a rotary draft tube bioreactor (회전식 통풍관 생물반응기로부터 생산된 느타리균의 다목적 과산화효소(VP) 정제 및 특성)

  • Hyo-Cheol Ha
    • Journal of Mushroom
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    • v.21 no.4
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    • pp.209-214
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    • 2023
  • In this study, Pleurotus ostreatus No.42 was cultured in glucose-peptone-yeast-wheat bran medium using a previously reported novel rotary draft tube bioreactor. Versatile peroxidase (VP), a lignin-degrading enzyme, was isolated from a pellet-type mycelium culture grown in the medium for seven days. The VP was purified by sequentially applying ultra-filtration, DEAE-Sepharose CL-6B column, and Mono Q column. SDS-PAGE analysis revealed the molecular weight of VP to be 36.4 KDa with an isoelectric point of 3.65. The amino acid sequence was confirmed as VTCATGQTT. The purified VP was observed to possess the property of not only oxidizing Mn ions but also decomposing veratryl alcohol, a non-phenolic compound. The catalytic ability of VP is a subject for future research.

The Effects of Hydrogen Peroxide Pretreatment on Rice Straw Fermentation for Feed (볏짚 발효사료 제조시 과산화수소 전처리 효과)

  • Choi, Yoon-Hee;Lee, Sang-Bok;Kim, Myeong-Sook;Hong, Jai-Sik
    • Applied Biological Chemistry
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    • v.37 no.5
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    • pp.326-333
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    • 1994
  • Pleurotus florida with high cellulase activity as well as lignin degradability was selected out among strains for fermentation of the rice straw to improve the nutritive value. When the rice straw was fermented by P. florida, the contents of hemicellulose, cellulose and lignin were decreased to 22.5%, 11.4% and 28.1%, respectively, whereas the contents of rice straw fermented after pretreatment with $H_2O_2$ or alkaline hydrogen peroxide were decreased much in the lower concentration. The content of T-N (total-nitrogen) and crude fat was increased with the longer fermentation period. The amino acid content of rice straw fermented by P. florida in 30 days was increased to 28.9% and 35.1% as the rice straw was fermented after pretreatment without and with 4% $H_2O_2$, respectively. The crystalline intensity of rice straw was decreased by pretreatment with 4% $H_2O_2$ and fermentation by P. florida. However, the crystall intensity was increased by treatment with alkaline hydrogen peroxide and the more when the straw was washed after the treatment. When the rice straw was fermented by P. florida for 30 days, the in vitro organic matter digestibility was increased up to 6% of $H_2O_2$ pretreatment.

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Studies on Photoprotection of Walnut Veneer Exposed to UV Light (자외선 노출에 의한 Walnut 베니어의 광 변색 방지 연구)

  • Park, Se-Yeong;Hong, Chang-Young;Kim, Seon-Hong;Choi, June-Ho;Lee, Hyo-Jin;Choi, In-Gyu
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.3
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    • pp.221-230
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    • 2018
  • The purpose of this study was to evaluate the effect of several chemical treatments to prevent photodegradation of wood veneer by external UV (Ultraviolet) light. Of woods, walnut veneer is selected as a raw material for this study since it is known as a luxurious wood with dark color giving an esthetic effect. Alcohol-benzene, hydrogen peroxide ($H_2O_2$) and sodium hypochlorite (NaClO) solution were used for investigate the effect on color stabilization. Despite the removal of the extractive compounds, which is known as a discoloration component, a significant color change of walnut wood veneer was observed. Meanwhile, the veneers treated by 20 and 30% $H_2O_2$ solution at $75^{\circ}C$ for 1 h also showed the no positive effect of color stability exposed to UV light although they have a bleaching effect on wood veneer. Besides, it was difficult to maintain the original color of walnut veneer due to the elution of the extractive compounds. On the other hands, the veneer treated by NaClO solution indicated the good performance on color stability despite of the intensive UV light test. However, when the concentration exceeds 3%, surface roughness and fiber damage occurred simultaneously. Therefore, the walnut species should be treated with proper concentration when sodium hypochlorite is applied to the veneer.