发酵工艺原理3.pptVIP

4. 微生物培养基 Cultural media A cultural medium is the substance in which a specific organism lives and grows. It must contain the essential nutrients needed for the microbe to grow. A good medium is very important to the success of an industrial fermentation. The medium supplies nutrients for growth, energy, building of cell substance, and biosynthesis of fermentation products. 4.1 培养基的类型及功能 Classifications of media and their functions 按纯度分类： --合成培养基 chemically defined media: compound identity and concentration of all components are known. Synthetic media --天然培养基 chemically undefined media: ingredients include one or more chemically complex substances such as protein hydrolysates and extracts. Crude media The choice of defined or undefined medium is dependent upon its application. ---Chemically defined media are useful in biochemical or metabolic studies of organisms. --General laboratory growth media and industrial media are often chemically complex. Such as 花生饼、蛋白胨等。一般不需外加微量元素 (trace elements)、维生素等。 按状态分类： -Solid media：suitable to culture and preserve species and spores; cultivating fungi. -Liquid media: 80%-90%water, industrial fermentation media. -Semi-solid media: liquid medium + agar 主要用于鉴定细菌、观察细菌运动特征等。 按用途分类 孢子培养基、种子培养基和发酵培养基 1.孢子培养基 spore media 要求：使菌体迅速生长，产生较多的优质孢子，不易引起菌种发生变异 (variation)。 基本配制要求：⑴ not rich in nutrition, especially organic nitrogen soure. ⑵ optimal mineral salt concentration ⑶ optimal pH and humidity 生产上常用孢子培养基： 麸皮、大米、小米培养基；由葡萄糖、蛋白胨、牛肉膏和食盐等配制的琼脂斜面培养基。 大米和小米常用作霉菌孢子培养基，因它们含氮少、疏松、表面积大，是较好的孢子培养基。水分控制在21％－25％。 种子培养基 inoculum media: 种子培养基是供孢子发芽、生长和大量繁殖菌丝体，并使菌丝体长得粗壮，成为活力强的‘种子’。 Inoculum media are usually less nutritious than are production media, and they usually contain a considerably lower level of the main nutritive carbon source. 一般种子培养基常包括有机氮源和无机氮源 最后一级的种子培养基的成分最好接近发酵培养基。 发酵培养基 production media 发酵培养基是供菌体生长、繁殖和合成产物之用。 要求：既要使种子接种后能迅速生长，达到一定的菌丝浓度，又要使长好的菌体迅速合成所需产物。 配制要求：其组