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1.
Katsunobu Ehara Yuka Iiyoshi Yuji Tsutsumi Tomoaki Nishida 《Journal of Wood Science》2000,46(2):180-183
A possible role of Tween 80 in the polyethylene degradation by manganese peroxidase (MnP) and the basis of the MnP action in the absence of hydrogen peroxide were investigated. The MnP activity in the system was retained its maximum level for 6 days in the presence of Tween 80. Tween 20 and CHAPSO stabilized MnP in the system similarly to Tween 80, and these surfactants also promote the polyethylene degradation. The system containing malonate buffer, Mn(II), and MnP produced Mn(III) in the absence of hydrogen peroxide, but the effect of Tween 80 addition on Mn(III) production in the absence of hydrogen peroxide was small. The results show that Mn(III) is generated by the MnP action initiated and amplified by the decomposition of malonate by Mn(III) and that a surfactant such as Tween 80 is required to stabilize MnP in the system.This study was presented in part at the 42nd lignin symposium, Sapporo, October 1997 and the 43rd lignin symposium, Fuchu, Tokyo, October 1998 相似文献
2.
Takeshi Iimori Shoichi Miyawaki Makoto Machida Kunichika Murakami 《Journal of Wood Science》1998,44(6):451-456
Unbleached and oxygen-bleached hardwood kraft pulp (UKP and OKP), respectively, were bleached with a culture filtrate containing manganese peroxidase (MnP) and lignin peroxidase (LiP) fromPhanerochaete chrysosporium Burds. The brightness increases of UKP upon biobleaching with the culture filtrate with and without MnSO4 were the same. The brightness increase of OKP with MnSO4 decreased to about half that seen without MnSO4. Changes in the brightness of UKP and OKP by treatment with the culture filtrate were determined. The brightness increased sharply by about eight points during the first 3h. The 3-h treatment was repeated seven times. The brightness increased linearly with the bleaching of UKP. On bleaching of OKP, the brightness increased slowly and stopped at about 78%.Part of this report was presented at the 62nd Pulp and Paper Research Conference of the Japan Tappi, Tokyo, June 1995 相似文献
3.
Structural changes of residual lignin in unbleached softwood kraft pulp (SWKP) during manganese peroxidase (MnP) treatment were investigated to obtain some understanding of the biobleaching action of SWKP with MnP treatment. Alkaline-extracted lignin from darkened SWKP by MnP showed more intense color and contained moreo-quinone than that from control SWKP. However, no difference in the conjugated-carbonyl was observed between the lignins from MnP-treated and control SWKP. The nitrobenzene oxidation analysis revealed that oxidative condensation of non-condensed lignin in SWKP occurs during an early stage of MnP treatment. These observations were supported by the model experiment in which the lignin prepared from control SWKP was subjected to MnP treatments three times, and the changes of color and functional groups in the lignin were determined after each treatment. These results suggested that an increase ino-quinone and the condensation reaction of non-condensed lignin in SWKP are responsible for the characteristic darkening of SWKP during MnP treatment. It was also ascertained that darkened lignin was degraded and brightened by repeated MnP treatments. 相似文献
4.
A marine white rot isolate, Phlebia sp. MG-60, secreted lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase under different sea salt incubation conditions.
Its MnP production was strongly enhanced by adding 3% sea salts, and the MnP showed high tolerance to sea salts and NaCl.
The crude enzyme secreted at 3% sea salt concentration by Phlebia sp. MG-60, in which the main component was MnP (cMnP), was then used to bleach unbleached hardwood kraft pulp (UKP) in vitro.
The pulp was brightened 11 points by 4 U of cMnP, and the kappa number was decreased 6 points when only 0.5 mM H2O2 was added continuously. When 0.5 mM H2O2 (1.22 mg H2O2 /g pulp) was added at the initial bleaching, the pulp brightness increased 6 points with a dosage of 4 U of cMnP. When crude
MnPs were employed to bleach UKP with organic-free model white-water instead of the Milli Q water usually used, the pulp was
brightened 10 and 13 points by 4 and 20 U of cMnP, respectively, and 5 and 6 points by 4 and 20 U of MnP, respectively, of
Phanerochaete chrysosporium.
Received: September 28, 2001 / Accepted: March 15, 2002
Correspondence to:R. Kondo 相似文献
5.
6.
Degradation of high-molecular-weight polyethylene membrane by lignin-degrading fungi, IZU-154, Phanerochaete chrysosporium, and Trametes versicolor, was investigated under various nutritional conditions. IZU-154 showed the most significant polyethylene degradation among the three lignin-degrading fungi under nitrogen- or carbon-limited culture conditions. Furthermore, for T. versicolor and P. chrysosporium, the addition of Mn(II) into nitrogen- or carbon-limited culture medium enhanced polyethylene degradation. These results suggest that polyethylene degradation is related to ligninolytic activity of lignin-degrading fungi. Treatment of polyethylene membrane with partially purified manganese peroxidase (MnP) caused significant degradation in the presence of Tween 80, Mn(II), and Mn(III) chelator. This result demonstrates that MnP is the key enzyme in polyethylene degradation by lignin-degrading fungi.This study was presented in part at the 9th International Symposium on Wood and Pulping Chemistry, Montreal, Canada, June 9–12, 1997 相似文献
7.
From among 419 wood-rotting fungi 10 were selected by the Poly R decolorization test, and their ability to bleach hardwood kraft pulp was assayed. Of the 10 selected, 6 fungi (i.e.,Phanerochaete crassa WD1694 and F150;Pleurotus pulmonarius PSC-H, PSC-M, and PSC-T;and Pleurotus species A119) showed much higher bleaching ability thanPhanerochaete chrysosponum BKMF1767 orTrametes versicolor WD1670, both of which are well-known high ligninolytic fungi.P. crassa WD1694 had the highest bleaching ability among the selected strains, and it increased the pulp brightness from 28 to 54, with a corresponding decrease in kappa number from 16 to 6 after 10 days of cultivation and alkali extraction. MnP was a predominant ligninolytic enzyme ofP. crassa WD1694 during the biobleaching.This research was presented in part at the 46th Annual Meeting of the Japan Wood Research Society, Kumamoto, April 1996 相似文献
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9.
竹浆GIF仿酶漂白木质素降解产物气相色谱-质谱解析 总被引：1，自引：0，他引：1
利用气相色谱-质谱联用(GC-MS)方法对GIF仿酶漂白中的木质素降解产物进行了分析,进一步探讨这种仿酶系统对木质素的降解机制.结果显示GIF仿酶处理使竹浆残余木质素进一步氧化降解,降解的主要方式有脱甲基作用、醌型结构的产生和开环、烷基-芳基醚键的开裂、侧链碳-碳连接的氧化断裂等.GC-MS检测所得的降解产物中,含羰基的化合物较多,这是GIF仿酶系统催化氧化的结果.一些醌式结构、共轭羰基和酚类的脱除,也使纸浆因发色基团减少而白度提高.此外,检测出一些糖类降解产物,说明GIF仿酶系统对纸浆碳水化合物有一定的降解作用. 相似文献
10.
世界木材制浆技术新进展 总被引：1，自引：0，他引：1
文章论述了木材制浆技术的新进展，在硫酸盐法制浆技术的革新方面，推荐了间歇蒸煮的快速置换加热（ＲＤＨ）技术与连续蒸煮的改良连续蒸煮（ＭＣＣ）和深度脱木素改良连续蒸煮（ＥＭＣＣ）技术。还介绍了超高得率制浆方法，特别是碱性过氧化氢机械制浆（ＡＰＭＰ）法和爆破制浆（ＥＰ）法，用这两种方法生产的纸浆得率高、白度高、强度高、能耗较低。 相似文献
11.
生物技术在制浆造纸工业中的应用前景 总被引：4，自引：0，他引：4
在制浆造纸工业中应用生物技术，在提高纸浆得率、降低纤维原料消耗量、消除污染、节约能源等方面具有较大潜力。作者从几个方面论述了生物技术的应用前景：生物改良树种、原木肃皮和木片贮存、生物制浆和漂白、高质量溶解浆的生产、废纸脱墨、利用造纸废液和废料制取副产品、废水处理。 相似文献
12.
Our previous paper showed tobacco stalks to posses the characteristics of a raw material for pulp and paper application. It contains the major biomass constituents and cell components common to wood species. In this study, preparation and characterization of tobacco stalk pulp by steam explosion (SE) pulping at two chemical pretreatments were attempted. Chemical pretreatment prior to SE pulping improved the brightness, yield, and strength properties of the resulting tobacco SE pulps in the order: 6% Na2SO3 + 1% NaOH > 6% Na2SO3 > control (untreated). The 6% Na2SO3 + 1% NaOH-impregnated tobacco stalks produced SE pulps of good fiber length distribution and considerable properties that compare well with pulps from other raw materials obtained from previous studies, and the nonimpregnated ones showed strength properties superior to those of their poplar counterpart. Prior to bleaching, pretreating the tobacco stalk SE pulps with two stages, 2% NaOH at 90°C, improved the initial pulp brightness by about 5 points. Two-stage 6% H2O2 bleaching gave a comparable effect with hypochlorite bleaching for both tobacco and poplar, giving a 29–34 brightness point increase for tobacco SE pulp and 61 for the poplar samples. The differences in the bleaching responses for untreated tobacco and poplar SE pulps were attributed to the differences in their lignin structure, as shown in the total yield of their respective nitrobenzene oxidation products and FT-IR spectra. Tobacco SE pulps contain more of the guaiacyl-type lignin and poplar the syringyl-type lignin.This paper was presented in part during the 1998 CORESTA (Cooperation Centre for Scientific Research Relative to Tobacco) Congress, Brighton, UK, October 1998 相似文献
13.
Crude Manganese Peroxidase (MnP) preparations from the fungus Bjerkandera sp. BOS55 were tested for their abilities to bleach and delignify oxygen delignified Eucalyptus Kraft pulp in a sequence combining a chelating and a peroxide stage. The inclusion of the enzymatic treatment in the bleaching sequence helped considerably to improve the final brightness. Other interesting results included moderate Kappa reduction, slight yield loss and paper sheets with an acceptable breaking length and burst index. 相似文献
14.
Katsuhiro Tokugawa Dan Aoki Ryutaro Asai Yasuyuki Matsushita Masao Ishiguro Yasufumi Noda Kazuhiko Fukushima 《Journal of Wood Science》2017,63(3):281-287
In order to understand the kraft pulp decolouring mechanism on using a nonionic detergent, the pulp washing process and the resulting pulp handsheets were investigated by examining the brightness, kappa number, thioacidolysis product yield, and dewatering efficiency in the pressing sheet making process. The pulp decolouring could be attributed to a decrease in the lignin content and an improvement in the dewatering efficiency. Furthermore, the detergent distribution in the aqueous pulp suspension obtained during the pulp washing process was visualised using cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM). The detergent was clearly observed at the transverse surface of the pulp fibre cell wall and was also detected in the lumen of the fibres, suggesting the permeation of the detergent into the pulp fibre cell wall. Based on these results, the pulp decolouring mechanism can be proposed as follows: the detergent permeates into the pulp fibre cell wall and promotes the solution-exchange between the inside and the outside parts of the fibre cell wall, finally washing away the chromophoric substances such as lignin and its degradation products owing to the enhanced dewatering efficiency. 相似文献
15.
对麦草在低温(85℃)下氧碱蒸煮,所得草浆在较低温度(80℃)下进行压力过氧化氢漂白。漂白后浆料卡伯值从17.9降至9.4～11.9;黏度比漂白前浆料黏度稍有增加,从1 042 mL/g增加到1 158～1 192 mL/g;纸浆白度(ISO)从37.1%升高至45.6%～60.6%,且与卡伯值之间具有一定的线性关系:白度增加=卡伯值降低×1.57;浆料得率在86.6%～89.5%之间,同时得率降低与卡伯值减少之间具有较为标准的线性关系:浆料得率降低=卡伯值降低×0.19。 相似文献
16.
Keiichi Koda Hitoshi Goto Hiroyuki Shintani Yuji Matsumoto Gyosuke Meshitsuka 《Journal of Wood Science》2001,47(5):362-367
Methanol liberation and methoxyl loss during chlorine bleaching of softwood kraft pulp were quantitatively investigated to estimate the degree of structural modification of lignin aromatics. An increase in the chlorine multiple led to enhanced methoxyl loss from lignin. Our result, using pH-adjusted chlorine water (pH 5.7), by which chlorination under oxidation-favorable conditions was achieved, strongly supported the importance of the oxidation reaction by chlorine during delignification and lignin degradation. It was also suggested that methanol can be produced not only via catalytic hydrolysis by chlorine but via oxidative cleavage of the ether bond as well. The infrared spectrum of chlorolignins suggested that chlorine oxidation can open aromatic rings to muconic acid derivatives without cleaving ether bonding of the methoxyl group. No straight relation between the methoxyl content and the kappa number of chlorinated pulps was shown. The methoxyl content of bleached kraft pulps subjected to successive chlorination and alkali extraction showed a good relation with the kappa number. This means that almost all the portions of the oxidatively modified lignin structure were successfully removed during these treatments, and the aromatic structures of residual lignin in chlorinated and alkali-extracted pulps were thought to remain intact.Part of this paper was presented at the 46th Annual Meeting of the Japan Wood Research Society, Kumamoto, April 1996; the 10th International Symposium on Wood and Pulping Chemistry, Yokohama, June 1999; and the 67th Pulp and Paper Research Conference, Tokyo, June 2000 相似文献
17.
Shinichi Yoshida Akinobu Chatani Yoichi Honda Takashi Watanabe Masaaki Kuwahara 《Journal of Wood Science》1998,44(6):486-490
The reaction of manganese peroxidase (MnP) of the white-rot fungusBjerkandera adusta with synthetic lignin dehydrogenation polymer, DHP) in acetone medium was investigated. Gel-permeation chromatography of the DHP treated by MnP demonstrated depolymerization of syringyl DHP in the reaction mixture containing 70% acetone; moreover, concomitant repolymerization occurred to give highly polymerized products. Guaiacyl DHP was only repolymerized by MnP in the same acetone solution without giving degradation products. Addition of ascorbic acid to reaction mixtures containing acetone resulted in preferential depolymerization of syringyl DHP.Part of this report was presented at the meeting of Kansai Branch, Japan Society for Bioscience, Biotechnology, and Agrochemistry in Kagawa, October 1996 相似文献
18.
Acetic acid pulping of wheat straw under atmospheric pressure 总被引：4，自引：0，他引：4
Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw was made of the chemical composition, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and fractionated into pulp (cellulose), acetic acid lignin, and sugars (monosaccharides from hemicellulose), making it easy to utilize them. It was found that among the pulping conditions the dosage of H2SO4 as catalyst was the most notable, and the extent and rate of delignification could be controlled by varying the amount of the catalyst. The results also showed that acetic acid pulp was quite different from soda-AQ pulp. About 70% of the ash or 90% of the silica in wheat straw were kept in AcOH pulp. The ash might function as filler and be beneficial to the printability of paper. It was known that many epidermal cells existed in AcOH pulp in bundles or in single cells. These ash-rich nonfiber cells seemed to hinder the bonding between fibers. AcOH pulp had lower strength than soda-AQ pulp, which might result mainly from the chemical damage of fibers caused by acid, not from the depolymerization of cellulose.Part of this paper was presented at the 65th Pulp and Paper Research Conference of Japan TAPPI, Tokyo, June 1998 相似文献
19.
In this investigation, the sorption of kraft lignin (KL) from spent liquors, membrane filtrated and model KL liquors on fully
bleached softwood kraft pulp fibres, was studied. The time, temperature and alkalinity during the sorption experiments were
chosen to reflect the conditions of black liquor impregnation of chips before the cooking operation. The amount of sorbed
KL was estimated by brightness and kappa number measurements. A linear correlation between the k value and the kappa number was found. Among the parameters investigated, the concentration of metal non-process elements
was found the most crucial for the sorption of KL on pulp fibres under black liquor impregnation. The influences of KL concentration,
metal ion profile and KL molecular weight distribution on the KL sorption behaviour under black liquor impregnation are discussed. 相似文献
20.
用绿色糖单孢菌复合胞外酶和纯木聚糖酶分别对三倍体毛白杨KP浆进行单段酶预处理及后续ECF、TCF漂白,结果发现,绿色糖单孢菌复合胞外酶助漂效果明显,接后续漂白可制得白度均高于85%ISO,粘度保持在1000mL/g左右的高白度、高强度、低氯和无氯全漂浆.相对传统纯木聚糖酶助漂,复合胞外酶在提高纸浆白度方面表现更佳,在保持纸浆粘度方面效果稍差.此外,三倍体毛白杨制浆漂白性能良好,ECF碱抽提段加入0.5%的H2O2可强化碱抽提效果,氧脱木素作用明显,是TCF漂白必不可少的组成部分. 相似文献