酿酒酵母发酵中乳酸菌染菌的智能化防控

发布时间：2018-03-20 23:03

本文选题：酿酒酵母　切入点：生物防控　出处：《北京化工大学》2014年硕士论文　论文类型：学位论文

【摘要】：化石资源的迅速开采和耗竭,以及其过度的使用不仅造成环境污染,并对我们的日常生活造成严重的影响。近年来,在我国已经有越来越多的城市空气质量不达标,形成这种现象的源头就是由于大量传统能源的使用,汽油柴油等能源依然是我国机动车的主要动力供给。发电、供暖则主要依靠燃煤,因而由此排放的CO、碳氢化合物、铅等大量有害物质直排入大气中,进而造成雾霾天气,并对人们的身体健康产生不良影响。因此,人们迫切需要开发可持续发展的新型清洁能源。将乙醇汽油混合,可提高汽油的辛烷值和氧含量,从而使汽油燃烧更充分,进而降低汽车尾气中的CO、碳氢化合物等含量。我国以及其他许多国家也都在推广乙醇汽油的应用。工业生产乙醇的方法主要有发酵法和合成法。酿酒酵母是酒精发酵的主要菌种。发酵法生产乙醇的过程中因仪器渗漏、种子带菌等原因经常导致发酵罐染菌,这成为工业上利用发酵法大规模生产乙醇的一个难题。工业发酵中细菌污染造成的损失巨大,所以人们必须认真对待染菌问题。针对染菌问题,人们已经摸索出一系列方法,如抑制染菌,药物抑菌(即加入抗生素法)、以酸制酸法以及加入乳酸法等。第一种方法都会存在药物的残留以及药物的抗性问题,第二种方法致使发酵液不能循环利用,造成浪费。利用噬菌体抑制发酵过程中的杂菌污染。对发酵过程中中酵母菌数量、植物乳杆菌数量、pH值、残糖量以及发酵终期的乙醇含量进行测定,进而利用PASW STATISTICS软件进行相关性分析,建立回归模型,从而得知发酵过程与染菌最相关的环境因素。基于并提出构想,利用包裹材料对噬菌体颗粒进行包裹制备,并形成对最相关环境因素进行响应释放。首先制备壳聚糖微球,利用扫描电子显微镜(SEM)对其形态大小进行测定。对微球进行液氮研磨,利用透射电子显微镜(TEM)对微球内部结构进行观察,以证明所制备微球是否具有核壳结构,是否具备包裹物质的基础条件。对噬菌体进行微球包裹,并对包裹噬菌体的微球在不同pH情况下的溶胀以及超微结构进行测定,从而验证壳聚糖微球成功包裹噬菌体颗粒,并且包裹后的微球可响应pH的变化。将包裹噬菌体颗粒的微球加入到模拟染菌的发酵体系中,并与模拟染菌的发酵体系发酵终期的乙醇含量进行比较,得出加入包裹噬菌体颗粒的微球的乙醇含量高于模拟染菌体系的乙醇含量(P0.01),表明在染菌发酵体系在加入包裹噬菌体颗粒的微球后,可有效控制发酵体系的染菌。
[Abstract]:The rapid exploitation and depletion of fossil resources, as well as their excessive use, not only cause environmental pollution, but also have a serious impact on our daily life. In recent years, more and more cities in our country have substandard air quality. The source of this phenomenon is the use of a large number of traditional energy sources. Gasoline, diesel and other energy sources are still the main power supply for motor vehicles in China. Lead and other harmful substances are released directly into the atmosphere, resulting in haze weather and adverse effects on people's health. Therefore, there is an urgent need to develop new clean energy sources for sustainable development. It can increase the octane number and oxygen content of gasoline, thus making gasoline burn more fully. In China and many other countries, the application of ethanol gasoline is also being popularized. The methods of industrial production of ethanol are mainly fermentation and synthesis. Saccharomyces cerevisiae is alcohol. The main strain of fermentation. In the process of producing ethanol by fermentation, the instrument leaks, Some reasons, such as seed carrying bacteria, often lead to bacterial contamination in fermenter, which has become a difficult problem for large-scale production of ethanol by fermentation in industry. The loss caused by bacterial contamination in industrial fermentation is huge. So people have to take the problem of bacterial contamination seriously. People have found out a series of methods to deal with the problem of bacterial contamination, such as inhibiting the contamination of bacteria. The first method will have the problem of drug residues and drug resistance, the second method will lead to the fermentation broth can not be recycled, resulting in waste. The number of yeast, the number of Lactobacillus plantarum and pH value, the amount of residual sugar and the content of ethanol in the final fermentation period were determined by bacteriophage in the fermentation process, and the correlation was analyzed by PASW STATISTICS software. A regression model was established to find out the most relevant environmental factors related to the fermentation process. Based on the conception, the phage particles were encapsulated by encapsulated materials. At first, chitosan microspheres were prepared. The morphology of chitosan microspheres was measured by scanning electron microscope (SEM). The microspheres were ground with liquid nitrogen. The internal structure of the microspheres was observed by means of transmission electron microscopy (TEM) to prove whether the microspheres had core-shell structure and the basic conditions for the encapsulation of the substance. The bacteriophage was encapsulated with microspheres. The swelling and ultrastructure of the bacteriophage encapsulated microspheres at different pH were determined to verify that chitosan microspheres successfully encapsulated phage particles. And the encapsulated microspheres can respond to the change of pH. The microspheres wrapped in phage particles were added to the fermentation system of simulated bacteria, and the ethanol content in the final fermentation period was compared with that in the simulated inoculation system. The results showed that the ethanol content of the microspheres coated with bacteriophage particles was higher than that of the imitated bacteriophage system (P0.01), which indicated that the bacteriophage inoculation system could be effectively controlled by adding the microspheres wrapped in the bacteriophage particles in the fermentation system.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TS261.1;R943

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