亚麻脱胶过程中常用酶类的动态变化

对亚麻快速生物脱胶和温水沤麻过程中的果胶酶、木聚糖酶、纤维素酶、微生物、pH值和还原糖等进行了动态变化研究。结果表明,2种脱胶过程中果胶酶和木聚糖酶的变化趋势基本相似,酶活性脱胶前期均增加缓慢,中后期迅速增加;纤维素酶活性的变化趋势有明显的区别,快速生物脱胶的纤维素酶酶活性增加幅度小,酶活性低(0.05 IU/mL左右),温水沤麻的纤维素酶在发酵72 h后迅速增加,脱胶完成后酶活性达0.337 9 IU/mL;微生物的变化趋势基本相似,在脱胶前期迅速增加、脱胶完成时开始下降;pH值和还原糖量的变化趋势分别呈“U”型和“M”型。     

Degumming of ramie bast fibers by Ca2+-activated composite enzyme

In recent years, special attention has been paid to the application of biotechnology in the textile industry. In this study, composite enzyme (contained pectatelyase/hemicellulase/laccase) was employed to degum the ramie bast successfully. Interestingly, the activities of enzymes were enhanced by promotion of Ca²⁺ activated remarkably. The test of degummed ramie fiber performance demonstrated that fiber fineness, breaking strength, whiteness, and residual gum of fibers have greatly improved. Further, the structure and morphous of the fibers before and after degumming was examined and analyzed. The results showed that the gum, hemicellulose, and lignin were removed effectively and treated fibers had the typical cellulose I structure suitable for direct textile and other applications. These outcomes suggested that Ca²⁺-activated composite enzyme could degum the gum of ramie bast effectively, which provided a method to improve the quality of ramie fibers and a theoretical basis for flax degumming technique on an environmentally-friendly basis.     

Biological Scouring of Flax Rove with Alkalophilic Strains

To achieve bio-scouring or biological degumming of the flax roving, a kind of eco-friendly techniques, an alkalophilic strain was screened from the rotten wrack around Zhoushan archipelago sea area. It was characterized as Cellulomonas sp and named Cellulomonas sp DA8 by measuring the strain morphology, physiology, biochemistry, and the 16s rDNA sequences. Determination of enzyme activity showed that the activities of petinase and xylanase were obtained, and enzyme activities are stable under 50°C and at pH values in the range of 6.5 to 9.0. It was utilized to scour the flax roving under alkaline conditions, and the result showed that the strain had a good characteristic of scouring, and less strength loss of flax fiber was 14.19%. Scanning electron microscopy (SEM) showed that the gum in the flax fiber was mostly degraded, and the most smooth fiber surface was displayed, compared with fiber untreated and scoured by caustic soda.     

Optimization of Enzyme Mixture Degumming of Ramie Fiber

An enzyme mixture was undertaken to improve degumming of ramie fiber. Optimum parameters of enzyme production were as follows: pH 8.45, temperature 40°C, inoculums size 5%, shaking speed 205 rpm, and degumming time 24 h. Using enzyme produced under the optimal conditions, the removal of residual gum of ramie fiber was 10.94% which fulfill the textile requirement. In addition, the fiber quality was measured to evaluate effective degumming and the gum in the ramie fiber was mostly degraded compared with chemical treated.     

基于射频处理的胡麻生物脱胶工艺

为缩短胡麻纤维的脱胶周期,降低生产成本,提升可纺性,对胡麻纤维的脱胶工艺进行了优化,并将射频热处理应用到脱胶过程中。通过场发射扫描电镜、白度测定仪和单纤维电子强力仪对胡麻纤维的表面形貌、白度、线密度和拉伸性能进行分析。结果表明,最佳的生物脱胶工艺为：处理温度为45 ℃,pH值为4.5,浴比为1：15,时间为25 h,加酶量为3 mL。射频处理显著的提升了胡麻纤维的分散性,改善了纤维表面形貌。此外,随着射频处理时间的增加,胡麻纤维的细度显著降低,但过长的处理时间会降低纤维的结晶度,影响纤维的拉伸性能,因此最佳的射频处理时间应为10~30 min。     

Application of enzyme in aqueous extraction of sesame oil

The oil recovery of the traditional process of extracting sesame oil by aqueous method could be improved by adding enzyme. Sesame oil was extracted under aqueous extraction conditions using three kinds of enzymes, which were papain, trypsin and cellulase. The optimal conditions were pH 7.0, 50 °C and extraction time 3 h with constant shaking at 80 rpm. The enzyme dosage and the enzyme proportion were researched by orthogonal experiment. The result indicated that the enzymes significantly improved the oil recovery. When the enzyme hydrolysis was performed with complex enzyme of papain 6,000 U, trypsin 400 U and cellulase 250 U/g oilseed, higher oil recovery (87.58 %) was achieved than the traditional aqueous extraction processing, and the oil was extremely fragrant. Moreover, the clear oil could fall directly from the centrifuge tube which greatly reduced the difficulty of separating oil.     

The effect of oxidation–reduction potential on the degumming of ramie fibers with hydrogen peroxide

Oxidation–reduction potential (ORP) was applied to monitor and control the oxidation reaction of peroxide hydrogen in the degumming process of ramie fibers. The effects of original pH, hydrogen peroxide dosage, oxidation temperature, and reaction time on ORP variations and fiber degumming efficiency were fully investigated. Central composite design method was used to optimize the degumming process. The optimum operating parameters were original pH 11.0, hydrogen peroxide dosage of 5.0 g/L, oxidation temperature of 85°C, and reaction time of 60 min, respectively. When the ORP value in the solution varied from +320 to +350 mV, it could achieve desired and reasonable degumming result. Under this range, the residual gum percentage of treated fibers was relatively lower and the mechanical property was better compared with other ORP values. This study could be instructive in online monitoring and control of ramie fiber preparation process using ORP as an indicating factor.     

Progress in Enzyme-Retting of Flax

Abstract

New methods for retting flax are sought to overcome problems in the current method of dew-retting of flax. Published data are reviewed and new data presented on the development and testing of a method to ret flax using pectinase-rich enzyme mixtures plus chelators based on cost and fiber yield and properties. In spray enzyme retting (SER), flax stems are crimped to physically disrupt the plant's protective barrier and then sprayed until soaked with, or briefly immersed in, an enzyme/chelator formulation. Flax is then incubated at temperatures optimal for enzyme activity, washed, and dried. Pilot scale tests, conducted with 10 kg samples of flax retted with a series of formulations, showed that this method effectively retted flax stems from a variety of sources, including fiber flax, mature fiber flax, and linseed straw. Fiber yield, strength, and fineness were significantly influenced by variations in enzyme-chelator amounts. Cellulases inpectinase mixtures appeared to preferentially attack dislocations in fibers and fiber bundles resulting in loss of fiber strength. Polygalacturonases alone effectively separated fiber from non-fiber components. The SER method proved to be an effective framework for further tests on enzyme-chelator formulations that now must be integrated with physical processing to optimize the extraction of flax fibers based on cost and fiber yield and properties.     

Production and characterization of milk-clotting enzyme from <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> JNU002 by submerged fermentation

Milk-clotting enzymes produced by microorganisms have been developed to replace calf rennet, yet the enzymatic level and the ratio of milk-clotting activity to proteolytic activity still need further improvement. This work described a strain Bacillus amyloliquefaciens JNU002 that screened from wheat bran that has a promising characterization. After optimization, B. amyloliquefaciens JNU002 showed a high milk-clotting activity (4969 SU/mL) and low proteolytic activity (4.02 U/mL) at 48 h with an inoculum size of 0.2% (v/v) at initial pH 6.0 in 15-L bioreactor. After purification, the purified enzyme gave a single protein band on SDS–PAGE, corresponding to 28 kDa. The purified enzyme showed a high ratio (2,575) of milk-clotting activity to proteolytic activity at 35 °C, and the ratio would be even higher (22,992) at 70 °C. The milk-clotting reaction and proteolytic reaction were prevented at 75 °C. This enzyme was stable at pH 4–6 and below 40 °C, and this was convenient for storage and transportation.     

Diversity and Characteristics of Kenaf Bast Degumming Microbial Resources

Kenaf is one of the most important natural fiber crops. Traditional degumming with water retting causes serious environmental pollution and reduces the quality of fiber products. The development of kenaf industry is hindered by high production cost. Microbial degumming is suitable for kenaf bast degumming because of its high efficiency, energy conservation, low pollution, and high quality, among others. Through enrichment and screening from water sample, soil sample, and humus sample, we concentrated and identified 92 bacterial strains that could degrade kenaf bast colloid. The strains belonged to 11 genera and 16 species. Five of these strains did not produce cellulase and the weight loss rate of the kenaf bast fiber raw material was more than 20%. These strains belonged to Bacillus subtilis, Paenibacillus polymyxa, Clostridium acetobutylicum, Bacillus alcalophilus, and Erwinia chrysanthemi and were assigned with serial numbers from K1–K5, respectively. This study is the first to report the function of Bacillus pumilus, B. alcalophilus, Clostridium tertium, Brevibacillus brevis, Pectobacterium carotovora, E. chrysanthemi, and Tyromyces subcaesius in kenaf bast degumming. Pectinase and mannanase were the key enzymes in the degumming of kenaf bast.     

复合重组磷脂酶用于大豆油脱胶的工艺优化

利用实验室前期构建的重组大肠杆菌所产磷脂酶A1（ p h o s p h o l i p a s e A 1, P L A 1）和磷脂酶C（phospholipase C,PLC）进行大豆油酶法脱胶研究,探讨自主开发重组酶进行酶法脱胶的可行性。以诺维信商品酶Lecitase Ultra™为对照,研究酶法脱胶反应温度、反应pH值、反应时间、搅拌速率、复合磷脂酶添加量工艺参数对大豆油脱胶的影响,并采用正交试验对脱胶工艺条件进行优化。研究结果表明,大豆油复合酶法脱胶的最佳工艺参数为：反应温度45 ℃、反应pH 6.5、反应时间3 h、搅拌速率300 r/min、PLA1和PLC添加量分别为7 940 U/kg和23 130 U/kg。复合磷脂酶对大豆油脱胶的效果与诺维信商品酶Lecitase Ultra™基本一致,大豆油磷含量可降至5 mg/kg以下,能够满足物理精炼的要求,为进一步开发具有知识产权的食品级油脂脱胶用酶制剂产品提供了理论依据。     

Survey and Recent Report on Enzymatic Processing of Bast Fibers

SUMMARY

In reference to previous presentations during meetings of Working Group 2 (WG2): “Bioprocessing of Bast Fibres,” acting within the COST Action 847 Project “Textile Quality and Biotechnology,” a further update of current world knowledge on biological processing of fiber plants and textiles was prepared. This survey covers the research on utilization of particular groups of enzymes in these processes. Main areas of enzyme application in bast fiber textile industry, according to literature from 2001-2004 are: degumming of bast fibers and scouring in textile industry (before and after bleaching).

The report also covers the results of studies on enzymatic processing of fiber plants carried out at the INF, in which the work is continued on application of enzymes in: degumming of flax straw, modifying of the short technical flax fibers, linen and hemp fabrics modification, and bonding of lignocellulosic composites.     

紫色红曲霉FBKL3.0018液态发酵产酯化酶的工艺优化

以分离自贵州某浓香型酒厂中温大曲的产酯化酶紫色红曲霉(Monascus purpureus)FBKL3.0018为研究对象,以发酵液中酯化酶活性为考察指标,通过单因素实验、Plackett-Burman实验和响应面试验对FBKL3.0018产酯化酶的发酵培养条件进行优化。由单因素实验得到FBKL3.0018产胞外酯化酶的条件为:2%牛肉膏、6%蔗糖、0.2%无水氯化钙和0.15%七水硫酸镁、初始pH4.5、发酵温度31 ℃、摇床转速160 r/min、装液量45 mL/250 mL、接种量9%和发酵时间96 h。PB结果表明,对酯化酶生产影响较显著的因素为发酵温度、发酵时间和蔗糖添加量。响应面优化实验得到的最优条件为:发酵温度31 ℃,发酵时间96 h,蔗糖浓度6%,在优化条件下,酯化酶活性为355.62 U/mL,比优化前(133.12 U/mL)提高了2.67倍,与预测值368.82 U/mL拟合率达96.4%,说明所建立的回归模型可靠。     

野生苎麻微生物脱胶优势菌的选育及其应用

为实现对野生苎麻的生物脱胶,采用平板稀释法从沤麻液中分离得到37株菌株,并采用平板透明圈法和DNS酶活测定法筛选野生苎麻生物脱胶用优势菌株。实验结果表明,TJ03菌株的透明圈与酶活值均为最大,其水解透明圈与菌落面积的比值为19.98,果胶酶酶活和甘露聚糖酶酶活分别为9.54、8.63 U/mL。最后对TJ03的脱胶条件进行了研究,得到其最佳脱胶条件为:初始pH值7.5,浴比1∶25,接种量15%,发酵时间4 d,发酵温度35℃。在上述条件下,野生苎麻生物脱胶后残胶率为14.09%,实现了纤维从韧皮中分离。     

生物酶前处理在稻秸秆纤维提取中的应用

分别用木聚糖酶和果胶酶对稻秸秆进行脱胶预处理,分析了生物酶作为前处理工艺对稻秸秆纤维性能的影响.以纤维残胶率、细度、强度及可挠度为指标,得出了这两种酶处理工艺的相对最优工艺参数.其中木聚糖酶前处理优化工艺为:木聚糖用量10％(owf),温度50℃,时间10 h,pH值为9,浴比1∶30;果胶酶前处理优化工艺为:果胶酶用...     

Azo dyes decolourization by the laccase from Trametes trogii

Dye decolourizing potential of laccase obtained from the white rot fungus Trametes trogii was studied for two reactive dyes; namely Reactive Black 5 (diazoic) and Reactive Violet 5 (monoazoic). The presence of a redox mediator as 1-hydroxybenzotriazole (HBT) was found to be essential for the decolourization of the said two dyes. The optimization of the decolourization process using experimental design was studied with three variables: dye (25, 50, 100 mg/L), enzyme (0.1; 0.5; 1 U/mL) and redox mediator (0.1; 0.5; 1 mM) concentrations. Results of this investigation revealed that the optimum concentrations of dye, enzyme and HBT for the degradation of the Reactive Black 5 (RB5) were 25 mg/L, 1U/mL and 1 mM, respectively, for a maximum decolourization about 93%. However, the optimum concentrations for Reactive Violet 5 (RV5) were found to be 25 mg/L, 0.5 U/mL and 0.5 mM, for a total removal of the dye. The apparent capacity of this laccase to decolourize azo dyes make it a suitable candidate for further applications in biobleaching and the treatment of textile effluents.     

A novel ionic liquid degumming process for Apocynum venetum

A novel degumming process for Apocynum venetum was presented using ionic liquid (IL)–water mixture in the paper. Optimum performance for the degumming of Apocynum venetum fiber was obtained in 80% (m/m) 1-butyl-3-methylimidazolium acetate ([BMIM][Ac]) at a temperature of 130 °C for 6 h, and the solution was maintained at the liquor ratio 1:20. The Apocynum venetum fibers before and after degumming were characterized by Scanning electron micrographs, Fourier transform infrared spectroscopy, and X-ray diffraction. The result showed that the Apocynum venetum fibers degummed with IL were longer than traditional chemical method, and the breaking strength of fiber with IL degumming process was significantly improved in comparison with traditional chemical method. Therefore, the IL–water degumming for Apocynum venetum fibers could dissolve the gum of fibers, and improve the spinnability of Apocynum venetum distinctly.     

脱胶方法对棉秆皮纤维成分及结构的影响

对原棉秆皮不同部位进行化学成分分析,利用常温水沤、常压脱胶及高压脱胶对棉秆皮进行处理,对脱胶后棉秆皮进行化学成分分析.实验结果表明:高压脱胶后棉秆皮纤维中的半纤维素和木质素含量下降最为明显,纤维素含量提高.对不同方法处理后的棉秆皮纤维的长度、线密度进行测量,用SEM、FT-IR、XRD对处理后的棉秆皮纤维表面形态结构、聚集态结构进行了表征,同时对脱胶后的棉秆皮纤维进行强伸性能等测试并得出断裂曲线.     

不同脱胶方法对野生苎麻纤维性能的影响

分别采用化学脱胶、微生物脱胶和微生物-化学联合脱胶3种方法对野生苎麻进行脱胶,测试了脱胶纤维的性能,并与人工种植苎麻进行了比较.结果表明在一定条件下,经3种不同方法脱胶后的野生苎麻纤维,残胶率最低为4.08%,最小细度为5.89 dtex,最大强度为5.59 cN/dtex,最大断裂伸长率为4.71%.     

亚麻纤维的脱胶工艺

针对亚麻纤维湿纺工艺复杂、流程长、混纺纱困难等问题,探讨了一种亚麻纤维的新型脱胶工艺,通过碱氧一浴、BK-100膨松剂浸泡、机械开松3道工序,运用物理与化学相结合的方法对亚麻纤维进行处理.实验结果表明,碱氧一浴最佳T艺参数为:NaOH 3.5%(o.w.f),H2O24%(o.w.f),煮练温度90℃,煮练时间80 m...