食品質(zhì)量與安全發(fā)酵工藝緒論

1、1 趙 蕾 Zhaolei, PhD College of Life Science Shandong Normal University E-mail: Fermentation Engineering 2How to study effectively? Give You a “PPT” P: Preview P: Practice T: Taking notes3What can we learn from this course?SkillsThinkingEnglishPoems4IntroductionConcept of fermentationHistory of fermen

2、tationTypes of fermentation productsSteps in industrial fermentation5The term fermentation is derived from the Latin verb fervere, to boil, which describes the appearance of the action of yeast on extracts of fruit or malted grain during the production of alcoholic beverages. What is fermentation? 6

3、Biochemists opinion (narrow sense) Fermentation is an anaerobic process (“l(fā)ife without air”) where energy is produced without the participation of oxygen or other inorganic electron acceptors. 7Microbiologists opinion (broad sense) Any process for the production of a product by the mass culture of m

4、icroorganisms. Definition of Fermentation Fermentation is the chemical transformation of organic substances into simpler compounds by the action of enzymes, which are produced by microorganisms such as molds, yeasts, or bacteria.9Fermentation is aunique process with great potentialEnvironment friend

5、ly Consume less energyEasy to manage 10History of fermentation Ethanol fermentation was one of the first chemical reactions observed by humans. In nature, various types of food go bad as a result of bacterial action. Early in history, humans discovered that this kind of change could result in the fo

6、rmation of products that were enjoyable to consume. 11Made the earliest microscopes which magnified up to 300X.Discovered micro-organisms.Pioneers in MicrobiologyAnthony van Leeuwenhoek(1632-1723)Leenvenhoek s microscope(1822-1895)Louis PasteurShowed microbes caused fermentation & spoilageDisproved

7、spontaneous generation of microorganismsDeveloped aseptic techniques14Louis Pasteurs germ theoryOld Theory: spontaneous generationmicro-organisms are the result of decaying matter.New Theory: germ theorymicro-organisms cause decaying matter.Pasteur showed you could kill the micro-organisms by applyi

8、ng heat Pasteurisation. 16（1843-1910） Developed pure culture methods.Established a sequence of experimental steps to show that a specific m.o. causes a particular diseaseKochs PostulatesRobert Koch17Single strain18The Nobel Prize in Chemistry 1907for his biochemical researches and his discovery of c

9、ell-free fermentationEduard Buchner 1860-1917Germany 19 In 1897, Buchner ground up a group of cells with sand until they were totally destroyed. Then he extracted the liquid and added it to a sugar solution. His assumption was that fermentation could no longer occur since the cells were dead. But he

10、 was amazed to discover that the cell-free liquid did indeed cause fermentation. 20Start from an ancient timeLarge scale production Early 20th century beverage industry, vinegar, baking yeast, citric (or lactic) acid Late 20th century development of biotechnology from the antibiotic industrialHistor

11、y of Fermentation engineering2122Major Products of Industrial Microbiology Industrial and agricultural products Fermented food and food additives Products for human and animal health23Micro-organisms cause changes in the foods which:Extend the shelf lifeProducing desirable taste and flavourImproveme

12、nt of nutritional valueProducing required physicochemical properties24 The product can either beThe cell itself: biomass production. A microorganism own metabolite: a product from a natural or genetically improved strain. 25Products from Microorganismsvinegar26Q: Why antibiotics , amino acid and enz

13、ymes could be produced by microbial fermentation ? 2727Types of microbial products Primary metabolites produce during growth stageinclude amino acids, nucleotides, fermentation end products and enzymes28 Secondary metabolites produce after growth stagehave no direct relationship to synthesis of cell

14、 material and natural growthinclude antibiotics , mycotoxins, pigment et al.293031Primary metaboliteMicroorganismSignificanceEthanolSaccharomyces cerevisiaealcoholic beveragesCitric acidAspergillus nigerfood industryAcetone andbutanolClostridium acetobutyricumsolventsLysine andGlutamic acidCorynebac

15、terium glutamaciumnutritional additive and flavour enhancerXanthan gumXanthomonas campestrisindustrialSecondary metaboliteMicroorganismSignificancePenicillinPenicillium chrysogenumantibioticStreptomycinStreptomyces griseus antibiotic32ContentsP.M.S.MGrowth needed?Yes NoSpecies specificity?NoYesProdu

16、ction stageduring active growthafter growth phaseExamplesamino acid, nucleotide,polysaccharide, vitaminantibiotics, toxin, hormones, pigment Produced steadily by cell regulationsdifferencessimilaritiesprimary metabolites vs. secondary metabolites33 Steps in Industrial FermentationScreen the best pro

17、ducing strainPrepare media and sterilization Optimize production conditionDownstream processing34seed fermentershake flaskstock cultureraw materialsmedium formulationsterilizationrecoverypurificationfermenterairproducts35Outline of a fermentation processUpstream processingDownstream processingRaw Ma

18、terialsProduction microorganismFermentationProduct purificationProductEffluent waste36FERMENTATIONProcess ControlFermentation engineeringUPSTREAM PROCESSESDOWNSTREAM PROCESSES37UPSTREAM PROCESSES- Producer microorganism- Inoculum development Media formulation Sterilization- Fermentation ProcessFERME

19、NTATIONProcess ControlFermentation engineering38The essential components of a fermentor39DOWNSTREAM PROCESSES - product extraction, purification & assay - waste treatment -by product recoveryFERMENTATIONProcess ControlFermentation engineeringThe ratio of recovery to fermentation costs for L-asparaginase: 3.0 ethanol: 0.1640How are microorganisms cultivated?Petri DishesShake FlasksFermentor41The Fermentation Process42I