第4章微生物的营养与培养基专题讲座.ppt

* * 为了分离特定的菌种，要求培养基尽可能只长目的菌，尽可能不长其他菌 ，2) 加富培养基 (enrichment medium) 在基础培养基中加入某些特殊营养物质 而制成一类营养丰富的培养基（血液、血清、 动植物组织液 等）。通常用来培养营养要求 较苛刻的异养微生物，或用来富集（数量上 占优势）和分离某种微生物。 3）选择培养基（selective medium） 根据不同种类微生物的特殊营养要求， 在培养基中加入相应物质，利于所需微生 物生长，抑制其它微生物。 例： 从混杂样品中分离纤维分解菌，石蜡油 分解菌，固氮菌，真菌，嗜盐菌，放线菌 （5）其他 * 分析培养基（assay medium） 分析某些化合物浓度 * 还原性培养基（reduced medium） 培养厌氧微生物 * 组织培养物培养基（tissue-culture medium） 培养病毒（鸡胚）、立克氏次体（鼠） TYPES OF CULTURE MEDIA TYPE PURPOSE Chemically defined Growth of chemoautotrophs and photoautotrophs, and microbiological assays. Complex Growth of most chemoheterotrophic organisms. Selective Suppression of unwanted microbes; encouraging desired microbes. Differential Differentiation of colonies of desired microbes from others. Enrichment Similar to selective media but designed to increase numbers of desired microbes to detectable levels. Table 4a. Minimal medium for the growth of Bacillus megaterium. An example of a chemically-defined medium for growth of a heterotrophic bacterium.  Component Amount Function of component sucrose 10.0 g C and energy source K2HPO4 2.5 g pH buffer; P and K source KH2PO4 2.5 g pH buffer; P and K source (NH4)2HPO4 1.0 g pH buffer; N and P source MgSO4 7H2O 0.20 g S and Mg++ source FeSO4 7H2O 0.01 g Fe++ source MnSO4 7H2O 0.007 g Mn++ Source water 985 ml pH 7.0 Table 4b. Defined medium for the growth of Thiobacillus thiooxidans, a lithoautotrophic bacterium. Component Amount Function of component NH4Cl 0.52 g N source KH2PO4 0.28 g P and K source MgSO4 7H2O 0.25 g S and Mg++ source CaCl2 2H2O 0.07 g Ca++ source Elemental Sulfur 1.56 g Energy source CO2 5%* C source water 1000 ml pH 3.0 * Aerate medium intermittently with air containing 5% CO2.? Table 5a. Complex medium for the growth of fastidious bacteria Component Amount Function of component Beef extract 1.5 g Source of vitamins and other growth factors Yeast extract 3.0 g Source of vitamins and other growth factors Peptone 6.0 g S