Isolation, characterization and enzymatic modification of water soluble xylans from Eucalyptus grandis wood and sugarcane bagasse
Isolation, characterization and enzymatic modification of water soluble xylans from Eucalyptus grandis wood and sugarcane bagasse
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DOI：
10.1002/jctb.3761
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发表时间：
2012-10-01
影响因子：
3.4
通讯作者：
Goergens, Johann F.
中科院分区：
文献类型：
--
作者：
Chimphango, Annie F. A.;van Zyl, Willem H.;Goergens, Johann F.
背景技术背景：利用木聚糖作为可生物降解的聚合物来替代合成添加剂、涂层和封装基质的兴趣越来越大。然而，对于这种应用，需要技术来降低木聚糖的水溶性。研究目的是从巨桉木材和甘蔗渣中分离和表征水溶性木聚糖，用于随后的酶改性水沉淀。结果：从大肠杆菌中提取出水溶性木聚糖。使用两种温和的碱-低温提取方法，其中木聚糖通过超纯化（Hoije）或乙醇沉淀（洛佩斯）回收。从甘蔗渣和E.用Hoije法和洛佩斯法分别测定了28%和12%。通过分别用α-L-阿拉伯呋喃糖苷酶和α-D-葡萄糖醛酸糖苷酶处理选择性去除阿拉伯糖和4-O-甲基葡萄糖醛酸（4-O-MeGlcA）侧链来水解木聚糖。α-L-阿拉伯呋喃糖苷酶去除了使用Hoije方法从甘蔗渣提取的木聚糖中约14%的可用阿拉伯糖，这导致在水中沉淀。然而，α-D-葡萄糖醛酸酶仅从甘蔗渣和E.使用Hoije和洛佩斯方法对grandis进行了测定，并且未能显示木聚糖在水中的可见沉淀。结论：从甘蔗渣中提取的木聚糖适合α-L-阿拉伯呋喃糖苷酶的底物特异性，用于侧链去除和在水中沉淀。然而，用于沉淀木聚糖的α-D-葡糖醛酸酶的剂量将需要增加。版权所有（c）2012化学工业协会
BACKGROUND: There is growing interest in utilizing xylans as biodegradable polymers to replace synthetic additives, coatings and encapsulation matrices. However, techniques are required to reduce the water solubility of the xylan for such applications. The study objective was to isolate and characterize water soluble xylans from Eucalyptus grandis wood and sugarcane (Saccharum officinarum L) bagasse for subsequent precipitation in water by enzymatic modification. RESULTS: The water soluble xylans were extracted from E. grandis and bagasse using two mild alkali-low-temperature extraction methods in which the xylan was recovered either by ultra-purification (Hoije) or ethanol precipitation (Lopez). Yields of 66 and 35% were obtained for the xylan extracted from bagasse and E. grandis, respectively, using the Hoije method and 28 and 12%, respectively, using the Lopez method. The xylans were hydrolysed by selective removal of arabinose and 4-O-methylglucuronic acid (4-O-MeGlcA) side chains by treatment with alpha-L-arabinofuranosidase and alpha-D-glucuronidase, respectively. The alpha-L-arabinofuranosidase removed about 14% of the available arabinose in the xylans extracted from bagasse using the Hoije method, which led to precipitation in water. However, the alpha-D-glucuronidase removed only 2% 4-O-MeGlcA of the available 4-O-MeGlcA from the xylans extracted from bagasse and E. grandis using both the Hoije and Lopez methods, and failed to show visible precipitation of the xylan in water. CONCLUSION: The xylans extracted from bagasse suited the substrate specificities of the alpha-L-arabinofuranosidase for side chain removal and precipitation in water. However, the dosage of alpha-D-glucuronidase for precipitating the xylan would need to be increased. Copyright (c) 2012 Society of Chemical Industry