Haloferax sulfurifontis GUMFAZ2 producing xylanase‐free cellulase retrieved from Haliclona sp. inhabiting rocky shore of Anjuna,Goa‐India

Salt stable cellulases are implicated in detritic food webs of marine invertebrates for their role in the degradation of cellulosic material. A haloarchaeon, Haloferax sulfurifontis GUMFAZ2 producing cellulase was successfully isolated from marine Haliclona sp., a sponge inhabiting the rocky intertidal region of Anjuna, Goa. The culture produced extracellular xylanase‐free cellulase with a maximum activity of 11.7 U/ml, using carboxymethylcellulose‐Na (CMC‐Na), as a sole source of carbon in 3.5 M NaCl containing medium, pH 7 at 40°C and produced cellobiose and glucose, detectable by thin‐layer chromatography. Nondenaturing polyacrylamide gel electrophoresis of the crude enzyme, revealed a single protein band of 19.6 kDa which on zymographic analysis exhibited cellulase activity while corresponding sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a molecular weight of 46 kDa. Unlike conventional cellulases, this enzyme is active in presence of 5 M NaCl and does not have accompanying xylanase activity, hence can be considered as xylanase‐free cellulase. Such enzymes from haloarchaea offer great potential for biotechnological application because of their stability at high salinity and is therefore worth pursuing.     

还原糖测定方法的规范

探讨了３,５－二硝基水扬酸（ＤＮＳ）添加量、显色时间、氧的溶解量、离子强度以及ＤＮＳ显色后存放时间对纤维素酶酶活力测定的影响．氧的溶解量对测定结果影响显著;测定波长的变化对检测样品光吸收值的灵敏度和线性范围影响很大,一般选定５４０ ｎｍ 为进行纤维素酶酶活力测定的波长．另外,当以葡萄糖为标准来测定还原糖时,不同的测定方法会使得纤维二糖的测定值不同．因此,在测定纤维素酶酶解产物时,用ＤＮＳ方法来测定还原糖,使测定结果更加准确．     

酶法-超声提取黄精总黄酮及其抗氧化活性研究

目的 研究酶法-超声提取黄精中总黄酮（total flavonoids from Polygonatum sibirici,TFPS）的最佳工艺及总黄酮的体外抗氧化活性。方法 以总黄酮含量为指标,采用单因素和正交试验对纤维素酶用量、乙醇浓度、液料比和超声时间进行考察,优化工艺条件并考察总黄酮对DPPH自由基、ABTS⁺自由基的清除能力和亚铁离子螯合活性。结果 最佳提取条件：纤维素酶用量为0.75%,乙醇浓度为40%,液料比为20 mL·g^-1,超声时间30 min,总黄酮含量为1.595%。体外抗氧化试验表明,黄精总黄酮对DPPH自由基、ABTS⁺自由基有很强的清除能力,IC₅₀分别为27.55,11.47 μg·mL^-1,对亚铁离子的螯合活性较强,IC₅₀为32.26 μg·mL^-1。结论 酶法-超声提取工艺具有提取效率高、稳定性及重复性好等优点,可用于黄精中总黄酮的提取,在该工艺下提取的总黄酮具有较强的抗氧化活性。     

虎杖中挥发性成分的酶提取及GC-MS分析

采用纤维素酶提取法（CE）和水蒸气蒸馏提取法（DSE）对虎杖药材草挥发油成分进行比较研究。利用气相色谱-质谱联用技术对其化学成分进行分析,从中分别鉴定出15种和18种化学成分,用峰面积归一法通过数据处理系统得出各化学成分在挥发油中的百分含量,酶处理后及未处理所得成分分别占挥发油总成分的51.24%和76.61%,共同组分中含量最多的是3-甲基-二苯并噻吩。     

泰山赤灵芝复合降解酶提取白花丹参须根有效成分的研究

目的:研究泰山赤灵芝复合降解酶在白花丹参须根有效成分提取中的应用.方法:采用木质纤维素复合降解酶来提取丹参须根中的有效成分,通过正交试验法优化酶解参数.结果:利用优化酶解工艺所得到的丹参须根提取液中总丹参酮和总丹酚酸的提取率可达11.923％,12.465％,比常规非酶法提取提高了62.794％,56.086％.结论:采用木质纤维素复合降解酶酶解法可以充分提取出丹参须根中的有效成分,为中药废弃物的再次利用提供了一条新途径.     

芽胞杆菌C14菌株鉴定及其碱性纤维素酶性质

从碱性污泥中分离到一株产碱性纤维素酶活力较高的耐碱性芽胞杆菌,所产的酶为单一的羧甲基纤维素酶(CMC ase),其专一性底物为羧甲基纤维素钠(CMC—Na)。酶的最适反应pH为9.0,在pH7.0～10.0范围内较稳定,酶作用的最适温度为55℃,在50℃时较稳定,在60℃处理10、30、60和90分钟后,残余酶活分别为91.5%、72.0%、36.7%和10.3.Co~(2 )、EDTA对酶促反应有明显的促进作用,Hg~(2 )、Ag~ 、Mn~(2 )和Zn~(2 )则有显著的抑制作用。     

Cellulose degradation in Gastrophysa viridula (Coleoptera: Chrysomelidae): functional characterization of two CAZymes belonging to glycoside hydrolase family 45 reveals a novel enzymatic activity

Cellulose is a major component of the primary and secondary cell walls in plants. Cellulose is considered to be the most abundant biopolymer on Earth and represents a large potential source of metabolic energy. Yet, cellulose degradation is rare and mostly restricted to cellulolytic microorganisms. Recently, various metazoans, including leaf beetles, have been found to encode their own cellulases, giving them the ability to degrade cellulose independently of cellulolytic symbionts. Here, we analyzed the cellulosic capacity of the leaf beetle Gastrophysa viridula, which typically feeds on Rumex plants. We identified three putative cellulases member of two glycoside hydrolase (GH) families, namely GH45 and GH9. Using heterologous expression and functional assays, we demonstrated that both GH45 proteins are active enzymes, in contrast to the GH9 protein. One GH45 protein acted on amorphous cellulose as an endo‐β‐1,4‐glucanase, whereas the other evolved to become an endo‐β‐1,4‐xyloglucanase. We successfully knocked down the expression of both GH45 genes using RNAi, but no changes in weight gain or mortality were observed compared to control insects. Our data indicated that the breakdown of these polysaccharides in G. viridula may facilitate access to plant cell content, which is rich in nitrogen and simple sugars.     

酶法提取玉米须总黄酮工艺研究试验

玉米须是禾本科作物玉米的干燥花丝和柱头,是一种来源丰富、价格低廉、易于采集收集的药材。近年的临床应用表明,其对高血压、糖尿病等疾病具有很好的疗效。但是,迄今有关玉米须化学成分及药理作用研究还很不深入和系统,致使绝大多数玉米须丢弃未得到充分利用。有试验表明,黄酮类化合物在玉米须中不仅有较高的含量还有较高的生物活性:例如玉米须黄酮提取物对增加机体运动负荷的适应能力、抵抗疲劳产生和加速疲劳消除方面具有明显的作用。因此玉米须具有良好的药用和食用价值,是一种极具开发前景的植物资源。玉米须化学成分及其药理作用研究会促进玉米须药物资源的规模开发并将带来巨大的经济效益和社会效益。本篇文章采用酶解法,以芦丁为标准品,测定玉米须中的总黄酮含量。正交实验结果显示,酶法最佳工艺组合为加酶量240U/g,pH值5.4,酶解温度50℃,酶解时间210min。在此工艺条件下提取,所得玉米须总黄酮提取率为0.8843%,而同等条件下不加酶的玉米须总黄酮提取率为0H6486%,酶法比不加酶提取率提高36.34%。     

高产中性纤维素酶菌株的诱变选育和筛选方法

设计了一种根据水解透明圈与菌落直径之比(D／d)以初步判断菌株产酶活力大小的方法,发现菌株的液体发酵酶活的对数(lgE)和菌落透明圈直径与菌落直径之比(D／d)基本上呈线性关系.采用紫外线和γ射线对中性纤维素酶产生菌木霉ZC(39 U／mL)进行了反复诱变和大量筛选,得到了一株高产中性纤维素高产突变菌株BE40-39(99 U／mL),并对出发株ZC和突变株BE40-39的性状进行了比较.     

苦荞茎叶粉中总黄酮酶法提取工艺研究

目的研究苦荞茎叶粉中总黄酮酶法提取工艺。方法苦荞茎叶粉经纤维素酶处理后用水提取总黄酮,研究酶加酶量、解温度、酶解时间和pH值对总黄酮得率的影响。结果酶法提取的最佳工艺条件为酶解温度55℃,加酶量3.0μL,pH值6.5,酶解90min,再在90℃下提取3次,每次30min,总黄酮得率可达1.47%。结论纤维素酶适用于苦荞茎叶粉中总黄酮的辅助提取。