降解竹材木质素高效复合菌系的构建及其发酵工艺研究
发布时间:2018-06-05 08:26
本文选题:竹材 + 木质素 ; 参考:《中南林业科技大学》2016年硕士论文
【摘要】:我国竹资源丰富,竹纤维具有绿色环保性、良好吸放湿性、天然抗菌和抗紫外线等特性,具有极大的市场潜力和附加值。竹纤维中木质素严重影响了竹纤维产业化开发的进程,而微生物降解木质素是解决这一问题的最有效途径。本文从降解竹材木质素所需的微生物入手,利用微生物繁殖快、易培养、降解能力强的特点,通过不同竹材品种化学成分的分析、构建降解木质素的复合菌系,研究复合菌系降解竹材工艺,研究结果为竹原纤维生物降解奠定基础。主要研究结果如下:1.不同竹材品种化学成分的研究通过对不同竹材品种,同种竹材品种不同年龄及不同部位竹材的灰分、木质素、综纤维素及果胶含量等重要化学成分分析,由于青皮竹或者毛竹的近中部位的竹材的化学成分中的灰分含量为2.07%、木质素含量为22.54%、综纤维素含量为76.86%、果胶含量为1.11%;毛竹竹材化学成分中的灰分含量为1.12%、木质素含量为27.49%、综纤维素含量为77.65%、果胶含量为0.92%,因此选用青皮竹或者毛竹的近中部位的竹材作为制浆原料的利用率较高,且能降低生产成本,减轻环境污染,提高竹材的持续经营和经济效益等优点。2.降解竹材木质素高效复合菌系的构建以不同菌株之间拮抗性、不同单菌株对竹材木质素降解效果为指标初筛选出不存在拮抗性且降解木质素能力高的菌株CN-12、HY-31、YY-36、ZYS-19;采用不同复合菌组合对生物量、竹材失重、竹材木质素的降解能力、竹材纤维素的降解能力、对降解选择性系数为指标复筛出高降解、高选择性的竹材木质素复合菌株组合HY-YY-ZYS,其对竹材失重率为27.33%,竹材木质素的降解能力为38.19%、竹材纤维素的降解能力为10.49%、降解选择性系数为3.64:且经过复合菌组合的稳定性研究,表明该复合菌株组合木质素降解能力稳定,平均降解率达到38.54%,比降解能力最强的单菌株(ZYS-19)的降解率提高了8.78%。3.复合菌降解竹材木质素固体发酵工艺条件研究以降解率和选择系数为主要指标,采用单因素优化方法结合均匀设计试验,对复合菌株组合(BY-YY-ZYS)固体发酵降解竹材木质素培养基条件进行了优化:竹粉(40目)15.0g,以1:3的料液比加入合成培养液,酒石酸铵0.2 g/L,葡萄糖14g/L, Ca2+0.8mmol/L,Mn2+ 0.6mmol/L时,降解率为46.29%,选择系数为10.72。以降解率和选择系数为主要指标,采用正交设计试验,对复合菌株组合(HY-YY-ZYS)固体发酵降解竹材木质素工艺条件进行了优化,结果表明:接种量为6%、含水量为50%、温度32℃、pH 5.0,在此条件下固体发酵25d时,竹材木质素降解率为60.29%,选择系数为12.79,降解率增加了21.75%,选择系数增加了9.15,降解时间缩短5d,竹材木质素降解率、选择系数,生产效率均得到了提高,且降低了生产成本。
[Abstract]:China is rich in bamboo resources, bamboo fiber has green environmental protection, good moisture absorption and desorption, natural antibacterial and anti-ultraviolet characteristics, with great market potential and added value. Lignin in bamboo fiber seriously affects the development process of bamboo fiber industrialization, and microbial degradation of lignin is the most effective way to solve this problem. Based on the microbes needed to degrade the lignin of bamboo wood, by using the characteristics of rapid propagation, easy culture and strong degradation ability, the complex strain of lignin degradation was constructed by analyzing the chemical composition of different bamboo varieties. The process of bamboo degradation by composite bacteria was studied. The results laid a foundation for the biodegradation of bamboo fiber. The main results are as follows: 1. The chemical constituents of different bamboo varieties were analyzed by analyzing the ash content, lignin, holocellulose and pectin content of different bamboo varieties, the same bamboo varieties, different ages and different parts of bamboo. Because the chemical composition of bamboo is 2.07, lignin is 22.54, holocellulose is 76.86, pectin is 1.11, bamboo ash is 1.12 and lignin is 1.12. The content is 27.49, the content of holocellulose is 77.65, the content of pectin is 0.92k.Therefore, the utilization rate of bamboo in the near and middle part of green bamboo or Phyllostachys pubescens as raw material for pulping is higher. And it can reduce the production cost, reduce the environmental pollution, improve the sustainable management of bamboo and economic benefits. 2. 2. The biodegradation of bamboo lignin efficient complex strain was constructed to antagonize between different strains. The effect of different strains on lignin degradation of bamboo wood was studied. The strain CN-12HY-31, YY-36, ZYS-19, which had no antagonism and high ability of lignin degradation, was selected initially, and the biodegradation ability of biomass, bamboo weight loss and bamboo lignin was studied by using different combinations of bacteria. The degradation ability of bamboo cellulose, the selectivity coefficient of degradation was the index of high degradation, The weight loss rate of HY-YY-ZYS was 27.33, the degradation ability of bamboo lignin was 38.19, the degradation ability of bamboo cellulose was 10.499.The degradation selectivity coefficient was 3.64: and the stability of compound bacteria combination was studied. The results showed that the lignin degradation ability of the compound strain was stable, the average degradation rate was 38.54, and the degradation rate of ZYS-19, the single strain with the strongest degradation ability, was 8.78.3. Study on the technological conditions for the degradation of lignin from Bamboo Wood by Composite bacteria the degradation rate and the selection coefficient were taken as the main indexes and the single factor optimization method was used to combine the uniform design test. The conditions of solid fermentation medium for the degradation of bamboo lignin by compound strain BY-YY-ZYS were optimized. The results showed that the degradation rate of bamboo lignin was 46.29g / L and the selectivity coefficient was 10.72when the mixture was added to the synthetic medium at 1:3, when ammonium tartrate was 0.2 g / L, glucose was 14 g / L, Ca2 was 0.8 mmol / L ~ (2) mn _ (2), the degradation rate was 46.29g 路L ~ (-1) and the selection coefficient was 10.72 g 路L ~ (-1) 路L ~ (-1) 路L ~ (-1). With the degradation rate and selection coefficient as the main indexes, the process conditions for the degradation of bamboo lignin by solid fermentation of compound strain combination HY-YY-ZYS were optimized by orthogonal design. The results showed that the inoculation amount was 6, the water content was 50, the temperature was 32 鈩,
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