4微生物的营养4微生物的营养.ppt

CRITICAL THINKING QUESTION How would you go about isolating a microbe that used gasoline 汽油for a food? 1.3 ENERGY 能量 1.Light (the sun or lamps) 2.Inorganic substances Sulfur 硫, CO2 or ammonia 氨 3.Preformed organic matter Sugar, protein, fats etc. 第三节 营养物质进入细胞方式 selective transportation Proteins in the membrane: ?typically span the whole membrane, contacting with the outside environment and cytoplasm. often require the expenditure of energy Four basic types of transport systems 四种传输方式 1.Simple (passive) Diffusion 单纯(被动) 运输 2.Facilitated Diffusion 促进扩散 3.Active Transport主动运送 4.Group Translocation 基团转移 4 Group translocation 基团转位 Protein-substrate: chemical modification No actual concentration takes place Most requires energy. Catabolic pathways sometime use Efficient: bring substrate into the cell and begin the breakdown process 第三节小结 Function of Culture Medium 1.Isolation maintenance of pure cultures 纯培养的分离和保存 2.Identification according to their physiological properties 鉴定细菌 Basal medium 基底培养基 NNN medium with blood含琼脂、盐及兔血的培养基;for trypanosoma锥虫属 1 Principles of medium design and selection 培养基设计与选择的原则 Objective 目的明确 Bacterial mass or metabolism products? Balanced nutrition 营养协调 Ten-time-rule: H2O C + energy N source P, S K,Mg growth factor 实验室的常用培养基： 细菌： 牛肉膏蛋白胨培养基（或简称普通肉汤培养基）； 放线菌：高氏1号合成培养基培养； 酵母菌：麦芽汁培养基； 霉菌： 查氏合成培养基； Appropriate physical chemical condition 物理化学条件适宜 1）pH: ?Bacteria: 7.0 ~ 8.0; Acetenomycets: 7.5 ~ 8.5 ?Yeast: 3.8 ~ 6.0; Mould: 4.0 ~ 5.8 Osmotic pressure aw: optimal aw0.6~0.998 1.Complex (undefined) medium天然复合培养基 exact chemical composition is not known most bacteria and fungi are grown with this 2.Chemically-defined (synthetic) medium 组合培养基 the exact chemical composition is known used to grow fastidious organisms 3.Semi-defined medium 半组合培养基 Complex (undefined) medium天然复合培养基 Chemical constitution not known成分未知 Usually contain complex materialsof biological origin (blood, milk, yeast or beef