《食品微生物学》课程教学资源（PPT课件讲稿）微生物的生长及其控制（The growth of microbe and its control）

Chapter 6 The growth of microbe and its control (微生物的生长及其控制)

Chapter 6 The growth of microbe and its control (微生物的生长及其控制)

Growth R eproduction: The relationship between individual and colony colony growth=individual growth individual reproduction

Growth： Reproduction： The relationship between individual and colony colony growth=individual growth + individual reproduction

Section a Determination of growth and reproduction (测定生长繁殖的方法) A. Determination of growth quantum(quantity), suitable for all microbes (测定生长量) B. Counting reproduction number, only suitable for unicelled bacteria and yeast, not for the filamentous moulds and actinomyces (计繁殖数)

Section A Determination of growth and reproduction （测定生长繁殖的方法） A. Determination of growth quantum（quantity）,suitable for all microbes. (测定生长量) B. Counting reproduction number, only suitable for unicelled bacteria and yeast, not for the filamentous moulds and actinomyces. (计繁殖数)

A Measuring of growth quantity (测生长量) Direct measuring(直接法) 1. volumetry 2. dry weight weighing Indirect measuring(间接法) 1, physiological index生理指标法 nitrogen content indexes carbon content P DNA RNA ATP DAP chitin etal 2. turbidimetry( nephelometry)比浊法

A. Measuring of growth quantity （测生长量） ◼ Direct measuring (直接法) 1.volumetry 2. dry weight weighing ◼ Indirect measuring(间接法) 1. physiological index 生理指标法 nitrogen content indexes carbon content P, DNA, RNA, ATP, DAP, chitin etal. 2. turbidimetry (nephelometry)比浊法

turbidimetry 90mm

turbidimetry

B Offspring counting 1. Direct ways(直接法) Using blood counting plate under the light microscope, the result is thethe total number including the dead cells. living cells and dead cells will be distinguished if staining with special dye before counting, thus both living cell number and the total number can be obtained respectively through this way

B. Offspring counting 1.Direct ways(直接法) Using blood counting plate under the light microscope, the result is the the total number including the dead cells. living cells and dead cells will be distinguished if staining with special dye before counting, thus both living cell number and the total number can be obtained respectively through this way

Direct counting under light microsope 盖玻片 侧面 计数室 正面 Structure of the counting area

Direct counting under light microscpe Structure of the counting area

Colorless( living) Yeast (methylene blue, Blue( dead observe under UV microscope Orange fluorescence (living cell Green fluorescence(dead cell)

Colorless ( living) Yeast (methylene blue) Blue ( dead) Bacteria stain with acridine orange (吖啶橙) and observe under UV microscope Orange fluorescence (living cell) Green fluorescence (dead cell)

The growth of filamentous microbe 、菌丝呈顶端生长 2、没有对数生长期 胞壁细胞膜 液泡 线粒体2 核糖体 泡囊 :11: 内质网 愚膜孔 指肪体 膜边体 、高尔基体

第三节 丝状微生物的生长 图6-3-1 腐皮镰孢霉生长曲线 0 1 2 3 4 5 0 10 20 30 40 时间（h） 干重（mg） 4 5 6 7 8 9 干重的自然对数（ug） 1、菌丝呈顶端生长 2、没有对数生长期 The growth of filamentous microbe

2. Indirect ways (living cell counting The methods are designed on the basis that living microbe can increase the turbidity while growing in liquid medium and can form colony on the solid medium. The most common used method Is colony-counting

2. Indirect ways (living cell counting) The methods are designed on the basis that living microbe can increase the turbidity while growing in liquid medium and can form colony on the solid medium. The most common used method is colony-counting