微生物的营养.ppt

无机盐的生理功能 微生物利用的氮源实验室： 　　铵盐 　硝酸盐 　 尿素 　蛋白胨 　牛肉膏 　　等 发酵工业： 　　　鱼粉 　　黄豆饼粉 　　蚕蛹粉 　　玉米浆 　　酵母粉 　　　等 生理功能 锌：乙醇脱氢酶、乳酸脱氢酶、碱性磷酸酶等 锰：过氧化物歧化酶、柠檬酸合成酶等 钼：硝酸还原酶、固氮酶、甲酸脱氢酶等 硒：甘氨酸脱氢酶、甲酸脱氢酶等 钴：谷氨酸变位酶 铜：细胞色素氧化酶 钨：甲酸脱氢酶 镍：脲酶 ★广义上说，凡是支持微生物生长繁殖的介质或材料均可作为微生物的培养基。 ★培养基是微生物学尤其是工业微生物学研究的重要内容。 Culture Media for the Growth of BacteriaFor any bacterium to be propagated for any purpose it is necessary to provide the appropriate biochemical and biophysical environment. The biochemical (nutritional) environment is made available as a culture medium, and depending upon the special needs of particular bacteria (as well as particular investigators) a large variety and types of culture media have been developed with different purposes and uses. Culture media are employed in the isolation and maintenance of pure cultures of bacteria and are also used for identification of bacteria according to their biochemical and physiological properties. The manner in which bacteria are cultivated, and the purpose of culture media, vary widely. Liquid media are used for growth of pure batch cultures while solidified media are used widely for the isolation of pure cultures, for estimating viable bacterial populations, and a variety of other purposes. The usual gelling agent for solid or semisolid medium is agar, a hydrocolloid derived from red algae. Agar is used because of its unique physical properties (it melts at 100 degrees and remains liquid until cooled to 40 degrees, the temperature at which it gels) and because it cannot be metabolized by most bacteria. Hence as a medium component it is relatively inert; it simply holds (gels) nutrients that are in aquaeous solution. 不同类群的微生物——细菌、放线菌、酵母菌、霉菌 不同营养类型微生物——自养菌、异养菌 特殊类型的微生物——如固氮菌 不同营养类型的微生物对营养的需求差异很大，应根据所培养的菌种对营养要素的不同需求进行配制。 四大类微生物常用培养基 2.注意各种营养物质的浓度与配比 营养物的浓度：在一般情况下，浓度合适的营养物质才对微生物表现出良好作用，浓度大时对微生物生长起抑制作用，浓度小时不能满足微生物生长的需要。 各营养物质之间的浓度比：培养基中各营养物质之间的浓度比直接影响微生物的生长与繁殖和（或）代谢产物的形成与积累，尤其是碳氮比（C／N）（碳氮比一般指培养基中元素碳与元素氮的比值，有时也指培养基中还原糖与粗蛋白两种成分含量之比）的影响更为明显