【作者】 钟安华；

【导师】 刘德立；

【作者基本信息】 华中师范大学 ， 生物化学与分子生物学， 2004， 硕士

【摘要】 本研究应用生物酶类脱胶方法对苎麻进行生物脱胶，试图寻找一种简便、廉价的苎麻脱胶生产加工方法，达到提高苎麻产品档次，同时保护环境的目的。论文探讨了满足苎麻生物脱胶的生物菌种应具备的条件，初步鉴定了菌种类别以及菌种的产酶类型；分析了菌种筛选、培育以及生物脱胶方法和碱液补充精炼的加工工艺；并总结了苎麻生物脱胶方法的特点。 我们分析了脱胶所需菌种的各种条件，然后进一步选育，得到了三种具有较好脱胶效果的嗜碱细菌，并对它们进行了较为深入的研究。初步鉴定了三种嗜碱细菌的菌种类型，分析了它们的酶学特性，探讨了嗜碱细菌的工艺条件和其他辅助条件对脱胶效果的影响以及细菌脱胶后的碱液补充精炼的工艺条件，并进一步讨论了生物脱胶后的苎麻各种性能以及脱胶后废液中的BOD、COD的数值。该生物脱胶方法简易，方便，实用。菌种脱胶初步残胶率达到9％左右，比酶类其他方法脱胶效果好。经较低碱液浓度(0.6％NaOH)进一步煮炼，残胶率为1％左右，完全符合纺纱要求。 结果表明：1)从不同污泥、土壤、污水中选取的800种不同菌种，在碱性条件下能生存的有320种。经碱性苎麻培养基筛选后，发现有3种嗜碱细菌脱胶效果好。B3、B6、B7残胶率初步测定分别为14.3％、12.1％、13.9％，其中B6效果最好。三株菌株初步鉴定为嗜碱芽杆孢菌。2)对嗜碱细菌酶学性能进行研究，将三株菌株以羧甲基纤维素为底物来测定纤维素酶，均测不出酶活力。将它处理的苎麻和JA纤维素酶处理过的苎麻分别用显微镜放大看毛羽，JA纤维素酶处理过的苎麻表面毛羽基本不存在，而B6处理过的苎麻表面毛羽很明显存在。用果胶培养基培养嗜碱细菌，测定果胶酶的活力，B6菌株产碱性多聚半乳糖醛酸酶的活力二天后达3710 U／ml；测定半纤维素酶活力，B6在半纤维素培养基和苎麻培养基中培养一天后的活力分别为105 U／ml和90 U／ml；测定木质素酶的活力，B6在苎麻培养基中培养，纤维中木质素含量由0.96％降到0.62％，降低了0.34％。3)脱胶工艺条件通过正交法确定，比较好的脱胶条件瞥硕士学位论文MASrER’ST}正515是:接种量为10%，脱胶时间为24h，pH10，温度40oC，残胶率为102%。另外芒麻通过脱胶前的机械预处理，然后脱胶20h，测定脱胶率比未处理的高4%;添加物如EDTA和缓冲液使脱胶率提高了1%;搅拌使脱胶率提高了1 .2%;原麻质量和重量并不影响脱胶率。为了达到纺纱要求，进一步用碱液精炼，碱液浓度仅为0.6%Na0H，残胶率为0.85%。4)脱胶后芒麻性能:通过菌种脱胶后，芒麻茎横截面中的兰麻组织在显微镜下可见松散的纤维;单纤维的强力比常规化学脱胶麻(0.57%)高0.15%:结晶度指数0.85，比化学脱胶的高0.08;用活性艳红1%(owf)染色，在30分钟后，生物脱胶的竺麻上色率比化学脱胶的高25%;排放液中的BOD、COD比化学法的分别低1 50一ZO0mg加l，400一6oomg/ml，生物法脱胶pH值为7一8，化学法脱胶pH为9一1 1 .5。 以上结果表明:l)嗜碱细菌来自自然界，容易得到，可用芒麻培养基培养，并能在碱性条件下生存，符合芒麻脱胶条件，脱胶效果好。2)三种嗜碱细菌不产生纤维素酶，产生果胶酶，半纤维素酶和木质酶，说明细菌不对竺麻纤维产生损伤，并且通过果胶酶等多种酶的联合催化作用，共同降解竺麻胶质中的多种组分，脱胶效果好。3)脱胶工艺条件为:接种量为10%，脱胶时间为24h，pH 10，温度40℃。脱胶前的机械预处理，添加物，搅拌等因素也能促进竺麻生物脱胶，但原麻质量和重量并不影响脱胶率。碱液补充精炼条件为:0.60;0 NaoH，10，0 Na3Po4，压力为Zkg/emZ，时l’ed Zh。通过生物与碱液的联合脱胶，完全可以达到纺纱要求。4)细菌脱胶后芒麻纤维完全可以从木质化的木质层中分化出来，有利于酶液渗透，便于脱胶。单纤维强力、结晶度系数均比化学法处理的芒麻高，并且生物脱胶提高了染色深度。废液中BOD、COD低，pH值近中性，大大保护了环境。总之，竺麻生物脱胶方法对竺麻企业在脱胶方面的技术改造奠定了基础。更多还原

【Abstract】 The biological scouring of ramie using enzymes was reported in this thesis. The convenient and cheap method of ramie scouring was explored in order to enhance the level of production and protect environment. It was discussed that the optimal qualification of bacteria using in the ramie scouring and the classification of these bacteria and their enzymes. The characteristics of ramie’s scouring were summarized including the bacteria selecting, cultivating, biological scouring and the scouring process of hydroxide’s supplement. Using selecting medium, 800 kinds of bacteria were detected from different regions, sludge, soil and waster water and 320 strains were alive in alkaline condition. Among them, only three kinds of alkaline bacteria (B3, B6 and B7) showed the ability of ramie scouring. These bacteria were preliminarily identified and their enzyme characteristics were analyzed. The technological process of the alkaline bacteria scouring, other assistant conditions on biological scouring and the technological process of hydroxide’s scouring were investigated. The characteristics of ramie having biological scouring and BOD, COD in the scouring waste through biological scouring were also discussed. It was found that this procedure was easy, convenient and practical. The preliminary remaining rate was 9% by the bacteria scouring that was much better than other scouring ways. The remaining jelly’s rate was further decreased to 1% boiled by adding lower concentration of hydroxide (only 0.6% NaOH). It was proved to be satisfied to the demand of yarning.The results showed: 1) 320 kinds of bacteria of 800 kinds from different dirt, soil and sewage could grow in the alkaline conditions, and only three kinds of bacteria (B3, B6 and B7) selected from the medium of ramie showed the better effect of scouring. The remaining rates of B3, B6, and B7 were respectively 14.3%, 12.1%, 13.9%, and B6 was the best. The three bacteria were preliminarily designated as the Bacillus alcalophilus. 2) The enzyme characteristics of the alkaline bacteria were described: they were not able to decompound the aceticMASTER’S THESISmethyl-cellulose, but B6 showed the activity of pectinase (3710 U/ml after two days). After B6 was cultivated in hemicellulose or ramie nutrition mediums for one day, the hemicellulose’s activity were 105 U/ml and 90 U/ml respectively. It was found that B6 cultivated in ramie nutrition medium could reduce the concentration of lignin from 0.96% to 0.62%. 3) The optimal process conditions, i.e. 10% inoculums ratio, 24 hours, pH 10, 40癱, were determined by the normal cross’s method. The rate of remaining jelly was 10.2%. After ramie pretreated mechanically and then scoured for 20 hours, and the scouring rate was more 4% than the control. The remaining jelly rate was decreased 1.2% and 1% respectively by agitation and by the addition of EDTA and buffer. The equality and quantity of initial ramie didn’t affect the scouring percentage. To satisfy the yarning demand, hydroxides could be used to further scour. The concentration of hydroxides was only 0.6% NaOH and the remaining jelly’s rate was 0.85%. 4) The ramie’s characteristics after scouring: The strength of single fiber was much more 0.15% than that of the usual ramie scoured (0.57%). The crystallinity index was 0.85, which was 0.08 much more than the method of scoured with chemistry. When ramie was dyed for 30 min with 1% active colorful red dyestuff (owf), the exhaustion of dyes by biological scouring was much more 15% than that by chemical scouring. BOD and COD in the biological waste liquid were respectively lower 150-200mg/L, 400-600mg/L than that in the chemical waste liquid. In the biological scouring pH was 7-8, while in chemical one pH was 9-11.5.The results indicated: that the alkaline bacteria come from nature and could be obtained easily. These bacteria can live in alkaline conditions and use in the ramie’s scouring demands. The three bacteria didn’t produce cellulosease, although they created pectinase, hemicellulase and ligninase. The biologi更多还原