1,Outline of a fermentation process,Raw Materials,Production microorganism,Fermentation,Product purification,Product,Effluent waste,Chapter 3 Strain Breeding and scale-up,Five Common Characteristics of Microorganisms,1. Small volume, large surface area 2. Fast absorption and conversion 3. Rapid duplication and growth 4. Strong adaptability 5. Widespread distribution and diversified species,What types of microorganisms cause fermentation to occur?,Bacteria Yeast Mold Actinomycetes,Bacteria Bacteria are typically one-celled organisms that multiply by simple division and can be seen only with a microscope.,1. Lactic acid bacteria Lactobacillusyoghourt Streptococcusyoghourt Pediococcus sour pickles Bifidobacteriumprobiotics,Lactobacillus,Streptococcus,Pediococcus,Bifidobacterium,2. Acetic acid bacteria Acetobactervinegar,3.Glutamic acid fermentative bacterium Corynebacterium glutamicum Brevibacterium flavum,4.Bacillus,Bacillus subtilis- protease ,amylase Bacillus licheniformis -protease , amylase,Yeast Yeasts are unicellular (single-celled) fungi and that ordinarily reproduce by budding.,Happy Yeast,Saccharomyces cerevisiae,1. Saccharomyces Saccharomyces cerevisiaebeer Saccharomyces ellipsoideuswine 2.Candida Candida utilis SCP,Mould Fungi that grow in the form of multicellular filaments, called hyphae. In contrast, microscopic fungi that grow as single cells are called yeasts.,1. Mucorchinese cheese 2. Rhizopus R.oryzoe amylase 3. Aspergillus A.nigercitric acid, glucoamylase A.oryzaesoy sauce, pasta (sweet)sauces,Fungi,Plant or animals,Actinomycetes,Microbes related to antibiotic producting,Streptomyces -streptomycin,About SCP, which is correct? A. Is a kind of protein which extracted from microbial cells. B. Is microbial cell which produced by fermentation. C. Is antibiotics secreted by microbial cells. D. Could not be regarded as food.,Can antibiotic producting microbes be used in the amino acids production?,Choosing Microorganisms for Industrial Microbiology 1.The nutritional characteristics of the organism. 2. The productivity of the organism, 3.The stability of the organism and its amenability to genetic manipulation. 4. The ease of product recovery from the culture.,Strain Selection,Purchase from Culture Collections Screening of nature circumstances Mutations Genetic engineering,Culture Collections,Steps of new species separation and screening,Screening of nature circumstances Most major sources of microbes for use in industrial microbiology are natural materials,Microbial strain collection 1. soil slurry 2. Enrichment Special media Control condition Inhibit unwanted strain,3. Isolation cultivation Streak plate method Pour plate method Spread plate method,Streak plate method,Bacteria are “streaked” over the surface of an agar plate so as to obtain single colonies. It can also highlight the presence of contaminating micro-organisms.,This is an example of a good streak for isolation using the “four corners“ method.,Performing a Plate Streak I,Performing a Plate Streak II,Pour plate method Bacteria are mixed with melted agar. Poured into an empty plate and allowed to solidify.,Spread plate method Small samples of the diluted bacteria are pipetted onto the surface of agar plates. A sterile, bent-glass rod is then used to spread the bacteria evenly over the entire agar surface.,稀释的,4. Pure cultivation Grow only one kind of microbe Must use aseptic technique to avoid contaminating the culture Transfer a single colony from agar plate to liquid medium,5. Productivity measurement Primary screening：quantity Secondary screening：quality,If I couldnt find an ideal strain from nature, how would I do?,Spontaneous (natural) mutation Induced mutation,mutation,Technique for inducing mutation,Physical mutagens e.g. X-rays, g-rays, UV Chemical mutagens e.g. base analogs, nitrous acid, alkylating agents,碱基类似物,亚硝酸,烷化剂,Steps:,How are mutants detected by scientists? Visible Nutritional (auxotrophic) What is replica plating, and how is it used to detect auxotrophic mutants? Resistance mutations (plate on media containing the chemical),营养缺陷型,影印培养法,降解纤维素 产生透明圈,摇床复筛,Replica-plating technique to screen for mutant strains of a colony-forming microorganism.,Q: How would you select for protease(amylase, celluase or lase)-producing mutant strain?,Cell Biology Techniques,Protoplast Removing the cell wall with lytic enzymes in the presence of osmotic stabilizers. In the presence of fusogenic agent such as polyethylene glycol (PEG), protoplasts are induced to fuse and form transient hybrids or diploids. Regeneration of viable cells from the fused protoplasts.,融合剂,二倍体,Genetic Engineering,Various high value added products have been produced from genetic engineering methods.,Culture preservation,dry,oxygen deficit,low temperaure,Culture preservation,Oligotrophe,菌种保藏的方法很多，一般有下面几种： A ：斜面冰箱保藏法 B：沙土管保藏法 C：石蜡油封