Experiment 2&3 1. Video: Culture Media Preparation and autoclaving 2. Discussion: Bacterial culture Sterilization and disinfection 3. Exercises. All students: Streak plates Group 1: Examination of the bacterial distribution Group 2: The ultraviolet radiation test Group 3: Effectiveness of hand washing
Experiment 2 & 3 1. Video: 2. Discussion: 3. Exercises: Culture Media Preparation and Autoclaving Bacterial culture Sterilization and disinfection All students: Streak plates Group 1: Examination of the bacterial distribution Group 2: The ultraviolet radiation test Group 3: Effectiveness of hand washing
Experiment 2 Bacterial cultivation
Experiment 2 Bacterial Cultivation
Requirements for bacterial growth Nutrients H2O, C-source, N-source, Inorganic salts, Growth factors Temperature ph Gas incubator Temperature, gas culture medium (R Nutrients, pH
3 Requirementsfor bacterial growth • • • Temperature Nutrients H2O, C-source, N-source, Inorganic salts, Growth factors pH Gas Temperature, gas Nutrients, pH n incubator culture medium ® ®
Culture medium is the mixture of various nutrients that is suitable for the growth of microorganisms Video: Culture medium preparation and autoclaving
4 n Culture medium – is the mixture of various nutrients that is suitable for the growth of microorganisms. Culture medium preparation and autoclaving Video:
Types of Culture Media based on the physical state based on the function and chemical components
n Types of Culture Media • • based on the physical state based on the function and chemical components
Based on the physical state Liquid medium Without agar for the proliferation of bacteria Solid medium: 1.5-2.5%agar for the isolation and identification of bacteria e.g., slant, Petri dishes/plates Semisolid medium: 0.3-0.5%agar for the observation of bacterial motility and preservation of bacteria
6 Based on the physical state Liquid medium Solid medium: Semisolid medium: • – – • – – – • – – : Without agar. for the proliferation of bacteria. 1.5-2.5% agar. for the isolation and identification of bacteria e.g., slant, Petri dishes/plates. 0.3-0.5% agar. for the observation of bacterial motility and preservation of bacteria
Bacterial growth patterns In liquid medium For the proliferation of bacteria Superficial growth 菌膜 Turbidity/diffuse Precipitate growing (sediment) 200-8-16 沉淀病室均浑浊
7 Bacterial growth patterns • In liquid medium: For the proliferation of bacteria Superficial growth; Turbidity/diffuse; Precipitate growing; (sediment)
In solid medium For the isolation and identification of bacteria Confluent growth/Smear Colony: a cluster of microorganisms growing on a solid medium. It is directly visible and arises from a single cell
§ In solid medium Colony For the isolation and identification of bacteria : Confluent growth / Smear; : a cluster of microorganisms growing on a solid medium. It is directly visible and arises from a single cell
Fai, P Colonies of s, aureus Colonies of Pseudomonas aeruginosa (medium sized, smooth and glossy, convex bigger colonies, irregular borderline opaque, inaurate liposolubility pigment) platode, moist, green water-soluble pigment) 金黄色葡萄球菌的菌落 铜绿假单胞菌的菌落 (中等大小、光滑、凸起、不透明、产脂溶(菌落大、边缘不整齐、扁平、湿润、产 性金黄色色素) 水溶性绿色色素)
Colonies of mediumsized, smooth and glossy, convex, opaque, inaurate liposolubilitypigment) Colonies of bigger colonies, irregular borderline, platode, moist, green water-soluble pigment) S. aureus Pseudomonas aeruginosa （ 金黄色葡萄球菌的菌落 （中等大小、光滑、凸起、不透明、产脂溶 性金黄色色素） （ 铜绿假单胞菌的菌落 （菌落大、边缘不整齐、扁平、湿润、产 水溶性绿色色素）
In semi-solid medium. For observation of bacterial motility and preservation of bacteria Only grow along the line of inoculation Grow diffusely(cloudy) A. non-motil B. motile
10 § In semi-solid medium: A. non-motile B. motile For observation of bacterial motility and preservation of bacteria • Only grow along the line of inoculation • Grow diffusely (cloudy)