微生物培养基课件.ppt

4. 微生物培养基 Cultural media;4.1 培养基的类型及功能 Classifications of media and their functions ;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：其组成除有菌体生长所必需的元素和化合物外，还需有合成产物所需的特定元素、前体和促进剂等。 In addition to the carbon and nitrogen compounds, a medium contains inorganic salts, vitamins, growth factors, precursors of fermentation products.;4.2 发酵培养基的成分及来源Composition of media and their sources;4.2.1 碳源 carbon sources ;4.2.1.1 糖类 sugars;molasses (糖蜜) Beet(甜菜) and cane molasses are by-products of the sugar industry. containing 50% -75% fermentable sugars, mainly sucrose. Also containing nitrogenous compounds, vitamins and minerals. Cheaper ;Starch and dextrin (糊精);油和脂肪 oils and fats;有机酸 organic acids;烃和醇类 hydrocarbon and ethanol ;4.2.2 氮源 nitrogen sources;organic nitrogen sources co