Microbial degradation of ether bonds between carbohydrates and residual lignin from kraft pulp

硫酸盐纸浆中碳水化合物和残留木质素之间醚键的微生物降解

基本信息

批准号：
05660189
负责人：
WATANABE Takashi
金额：
$ 1.34万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05660189/
关键词：
Kraft Pulp Biobleaching LCC White-rot fungi Lignin

项目摘要

A water-soluble xylanase-resitant chromophoric xylan fraction (LF-D) was separated from a hard wood unbleached kraft pulp (UKP) by a cellulase/xylanase bioreactor and silica gel column chromatography. Chemical and spectroscopic analyzes revealed that LF-D contained a large amount of unremovable inorganic atoms including Si, Na and S,together with non-branched beta-1,4-linked xylan chain. In a nitrobenzen oxidation of LF-D,existence of a large amount of qunoid structure was suggested. In adittion, it was found that lignin in LF-D had been demethylated during the course of kraft pulping. On the other hand, a higher molecular weight residual fraction (HF-P) was found to contain much diphenylmethane (DPM) structure. LF-D was more effectively decolorized by bacterial microflora from soil rather than selected white rot fung. However, C.versocolor was found to decolorize both the chromophric xylan fraction and intact UKP itself among the white-rot fungi tested. In both cases, activities of lignin peroxidase, Mn-peroxidase, laccase and xylanase were not detected during the hole time of cultivation.Although a purified LiP (H8) from P.chrysosporium wa oxidized a p-ethylated beta-O-4LCC model, carbohydrate moiety was not detected in the reaction mixture. Therefore, screening of microorganisms which quantitatively cleave p-etherified benzyl ether bonds was carried out using a fluorescence-sensitive benzyl ether model compound. As a result, several bacterial single colonies which emit fluorescence were isolated. Further study on the characterization of these microorgansims would lead to an environmentally safe biobleaching system of pulps.

水溶性木聚糖酶耐染色的木聚糖馏分（LF-D）通过纤维素酶/二甲那酶生物反应器和硅胶柱色谱从硬木未漂白的牛皮纸（UKP）分离。化学和光谱分析表明，LF-D包含大量无机的无机原子，包括Si，Na和S，以及非支柱的β-1,4-链接的Xylan链。在LF-D的硝基苯氧化中，建议存在大量的Qunoid结构。在Adittion中，发现LF-D中的木质素在牛皮纸制浆过程中已被脱甲基。另一方面，发现较高的分子量残留分数（HF-P）含有大量的二苯基甲烷（DPM）结构。 LF-D通过细菌菌群从土壤中更有效地脱色，而不是选定的白色腐烂。然而，C。crocolor被发现在被测试的白rot真菌中脱色化的Xylan馏分和完整的UKP本身。在这两种情况下，木质素过氧化物酶，Mn-过氧化物酶，漆酶和木聚糖酶的活性均未在培养时间内检测到。尽管未在氧化的含有P. chrysosporium wA的纯化唇（H8）中氧化了P-乙基化的Beta-O-4LCC模型，在该反应中未检测到P-乙基化的β-O-4LCC模型，碳水化合物模型，碳水化合物模型，碳水化合物模型。因此，使用荧光敏感的苄基醚模型化合物对微生物进行定量裂解的二醚二醚键进行筛选。结果，分离了几个细菌单菌群，它们发出荧光。进一步研究这些微角质的表征将导致环境安全的牙髓生化系统。