LIQUEFACTION OF DULSE (PALMARIA-PALMATA (L) KUNTZE) BY A COMMERCIAL ENZYME PREPARATION AND A PURIFIED ENDO-BETA-1,4-D-XYLANASE
LIQUEFACTION OF DULSE (PALMARIA-PALMATA (L) KUNTZE) BY A COMMERCIAL ENZYME PREPARATION AND A PURIFIED ENDO-BETA-1,4-D-XYLANASE
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DOI：
10.1007/bf02185790
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发表时间：
1992-12-01
影响因子：
3.3
通讯作者：
VIGOUROUX, J
中科院分区：
文献类型：
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作者：
LAHAYE, M;VIGOUROUX, J
用食品级酶制剂和纯化的内切-β-1，4-D-木聚糖酶对棕榈树的干、鲜棕榈进行液化，从商品食品级黑曲霉制备的酶中提纯内切-β-1，4-D-木聚糖酶(EC 3.2.1.8)。其相对分子质量为22 500，等电点为3.5，对阿拉伯木聚糖、对硝基苯基-β-D-木糖、羧甲基纤维素无活性，对微晶纤维素活性较弱。它在海水和去离子水中同样能很好地将燕麦和木聚糖水解成木糖和木二糖。该酶在pH 5.5~9.0和0~30℃范围内稳定，在pH 4.5~5.5和40~60℃时活性最高。燕麦和木聚糖酶的K(M)分别为2.2和2.8mgml-1，V(Max)分别为3600nkat和3900nkat mg-1，醋酸盐缓冲液、去离子水和海水单独提取干重的62.6~64.5%，而使用食品级酶制剂或纯化的木聚糖酶可使液化提高到81.2~87.1%。木糖和半乳糖是可溶性提取物中仅有的两种糖。去离子和海水分别提取了秋季和夏季采集的新鲜藻类干重的58.8-52.7%和39.1-42.2%。新鲜秋藻海水提取物中只有半乳糖存在，而去离子水提取物中有木糖和半乳糖的存在。纯化的木聚糖酶和粗木聚糖酶可使新鲜藻类在去离子和海水中的液化分别达到新鲜干重(秋季和夏季)的79.8~81.4%和71.9~77.9%，并提高了可溶性组分的木糖含量。可溶性残渣中的多糖主要由1，3/1，4-连接的木糖、1-连接的半乳糖(氟烷糖苷)和1，4-连接的葡萄糖(纤维素)组成，酶处理后得到的不溶部分主要含有1，4-连接的木糖和1，4-连接的葡萄糖。这项研究表明，干燥等处理可以显著改变棕榈藻细胞壁多糖的溶解度，这可能意味着新鲜细胞壁中存在降低木聚糖在海水中溶解度的某些组织和/或其他成分。
Liquefaction of dry and fresh Palmaria palmata by food grade enzyme preparations and a purified endo-beta-1,4-D-xylanase was studied.The endo-beta-1,4-D-xylanase (EC 3.2.1.8) was purified to homogeneity from a commercial food grade enzyme prepared from Aspergillus niger. It has a molecular weight of 22 500, a pI of 3.5, is inactive toward com arabinoxylan, p-nitrophenyl-beta-D-xylose, carboxymethyl cellulose but shows a weak activity toward microcrystalline cellulose. It hydrolyzes oat and dulse xylan equally well in seawater and deionized water essentially into xylose and xylobiose. It is stable between pH 5.5 to 9.0 and 0 to 30-degrees-C and its activity is optimal at pH 4.5-5.5 and 40-60-degrees-C. It has a K(m) of 2.2 and 2.8 mg ml-1 and V(max) of 3600 and 3900 nkat mg-1 of protein on oat and dulse xylan, respectively.Acetate buffer, deionized water and seawater alone extracted 62.6 to 64.5% of the dry weight of dry dulse, but the use of commercial food grade enzyme preparations or the purified xylanase improved liquefaction to 81.2-87.1%. Xylose and galactose were the only sugars present in the soluble extracts. Deionized and seawater extracted 58.8-52.7 and 39.1-42.2% of the dry weight of the fresh algae collected in fall and summer, respectively. Only galactose was found in the seawater extract, while some xylose with galactose were measured in the deionized water extract of the fresh autumn algal sample. Purified and crude xylanase improved liquefaction of fresh algae to 79.8-81.4 and 71.9-77.9% of the fresh dry weight (fall and summer, respectively) in deionized and seawater, respectively, and increased the xylose content of the soluble fractions. Polysaccharides in the soluble residues were composed of 1,3/1,4-linked xylose, 1-linked galactose (floridoside) and 1,4-linked glucose (cellulose) and contained essentially 1,4-linked xylose and 1,4-linked glucose in insoluble fractions obtained after enzymatic treatment.The use of xylanase-containing food grade enzyme preparations improves liquefaction of Palmaria palmata, particularly from fresh alga. This study indicates that processing such as drying may modify markedly the solubility of P. palmata cell wall polysaccharides, which would imply the existence of some organization and/or other components in the fresh cell wall that lower xylan solubility in seawater.