微生物學(xué)(緒論)88課件

1、食品微生物學(xué)FOOD MICROBIOLOGY霍 乃 蕊山西農(nóng)業(yè)大學(xué)食品科學(xué)與工程學(xué)院 Food MicrobiologyLectured by Huo Nairui College of food science and engineeringIntroduction What is a microbe? A microbe or microorganism is a member of a large, extremely diverse, group of organisms that are lumped together on the basis of one property -

2、the fact that, normally, they are so small that they cannot be seen without the use of a microscope. The word is therefore used to describe viruses, bacteria, fungi, protozoa and some algae.The observation of microbe need to via the light microscope or EM個(gè)體形態(tài)需要借助光學(xué)顯微鏡或電子顯微鏡觀察。 微生物(microorganism)：是存在

3、于自然界的一大群體形微小、結(jié)構(gòu)簡(jiǎn)單、肉眼直接看不見(jiàn)，必須借助光學(xué)顯微鏡或電子顯微鏡放大數(shù)百倍、數(shù)千倍，甚至數(shù)萬(wàn)倍才能觀察到的微小生物。exceptions1.the fruiting bodies of many fungi such as mushrooms are frequently visible to the naked eye; However, there are a few exceptions, 2. equally, some algae can grow to meters in length.Green algaedinoflagellateBrown algaedia

4、tomRed algaealgaeThe colony or lawn can be seem with the naked eye肉眼可觀察到微生物聚集的群體菌落 或菌苔 微生物與人類的關(guān)系絕大多數(shù)微生物對(duì)人類和動(dòng)、植物是有益的，而且有些是必需的。1.在自然界中元素的循環(huán)2.在工業(yè)方面的作用3.在農(nóng)業(yè)方面的作用4.在醫(yī)藥方面的作用5.生物技術(shù)6.科學(xué)研究只有少數(shù)的微生物對(duì)人類和動(dòng)、植物是有害的。The importance of microbiologyThe environmentMedicineFoodBiotechnologyresearchThe environment (1)1.M

5、icrobes are responsible for the cycling of carbon, nitrogen and phosphorus (geochemical cycles), all essential components of living organisms . 2.They are found in association with plants in symbiotic relationships.The environment (2)3.Maintain soil fertility and may also be used to clean up the env

6、ironment of toxic compounds (bio-remediation). 4.Some microbes are devastating plant pathogens which destroy important food crops, but others may act as biological control agents against these diseases.medicine The disease-causing ability of some microbes such as smallpox (Variola virus), cholera (V

7、ibrio cholera bacteria; ) and malaria (Plasmodium protozoa. ) is well known. However, microorganisms have also provided us with the means of their control in the form of antibiotics and other medically important drugs.Food Microbes have been used for thousands of years, in many processes, to produce

8、 food, from brewing and wine making, through cheese production and bread making, to the manufacture of soy sauce At the other end of the scale, microbes are responsible for food spoilage, and disease-causing microbes are frequently carried on food.research Microbes have been used extensively as mode

9、l organisms for the investigation of biochemical and genetical processes as they are much easier to work with than more complex animals and plants. Millions of copies of the same single cell can be produced in large numbers very quickly and at low cost to give plenty of homologous experimental mater

10、ial. An additional advantage is that most people have no ethical objections to experiments with these microorganisms.Eukaryotic microbes （真核細(xì)胞型微生物）細(xì)胞核分化程度高，有核膜和核仁，細(xì)胞器完整。如真菌。Prokaryotic microbes （原核細(xì)胞型微生物）細(xì)胞核的分化較低，僅有原始核，無(wú)核膜、核仁。細(xì)胞器很不完善。DNA和RNA同時(shí)存在。這類微生物眾多，有細(xì)菌、放線菌、支原體、衣原體、立克次體、螺旋體。Non-cell type microbe

11、s（非細(xì)胞型微生物是最小的一類微生物。無(wú)典型的細(xì)胞結(jié)構(gòu)，只能在活細(xì)胞內(nèi)生長(zhǎng)繁殖。核酸類型為DNA或RNA。病毒屬之。3 types 8 kinds（三型八大類）Microbe typesAnimalia： some protozoaplantae： some microalgaeprotista： some protozoa、most alga and myxomycota fungi： yeast and mouldprocaryotae： bacteria，actinomycete,cyanobacteriaVira：virusesCell typeMicroorganismsNon -c

12、ell typeMicrobe types 病毒作為一界被提出的較晚，主要原因是：病毒和類病毒是生物還是非生物，是原始類型還是次生類型是長(zhǎng)期爭(zhēng)論未決的問(wèn)題；病毒不是用雙命法，分類不用階元系統(tǒng)。但經(jīng)過(guò)長(zhǎng)期研究發(fā)現(xiàn)，病毒和細(xì)胞型生物具有共同特性：遺傳物質(zhì)是DNA(部分病毒是RNA)；使用共同的遺傳密碼。在此基礎(chǔ)上，我國(guó)學(xué)者于1979年提出將無(wú)細(xì)胞結(jié)構(gòu)病毒立為病毒界，從而建立了六界系統(tǒng)。 真菌的形態(tài) 桿菌 原核生物常見(jiàn)種類和常見(jiàn)形態(tài)（1） 球菌原和生物常見(jiàn)種類和常見(jiàn)形態(tài)（2）藍(lán)細(xì)菌（螺旋藻）藍(lán)細(xì)菌（魚(yú)腥草）原和生物常見(jiàn)種類和常見(jiàn)形態(tài)（3） 古細(xì)菌（產(chǎn)甲烷細(xì)菌）細(xì)菌（耶爾森鼠疫桿菌）Slime mol

13、ds（粘菌類生物）孢子體粘菌類生物是原生生物中數(shù)量較少的一類，在其生長(zhǎng)期或營(yíng)養(yǎng)期為裸露的無(wú)細(xì)胞壁多核的原生質(zhì)團(tuán)，又叫變形體，在繁殖時(shí)期會(huì)形成多細(xì)胞的孢子囊構(gòu)造并產(chǎn)生具有纖維質(zhì)細(xì)胞壁的孢子。粘菌大多數(shù)生于森林中陰暗潮濕的地方，在腐木，落葉或其他濕潤(rùn)的有機(jī)物上生長(zhǎng)。Slime molds（粘菌類生物）一個(gè)變形體Slime molds（粘菌類生物）Biological features of microorganisms微生物的生物學(xué)特性Powerful metabolic ability 代謝活力強(qiáng)Propagate rapidly 繁殖快Diverse species and widely di

14、stributed 種類多、分布廣High adaptability and easily mutated 適應(yīng)性強(qiáng)、易變異在人類可以生存的環(huán)境中，微生物無(wú)處不在 一般城市街道每立方米的空氣中約含5000個(gè) 普通宿舍的空氣中每立方米約含20000個(gè) 每克肥沃土壤中可含數(shù)億個(gè)甚至更多的微生物 微生物在自然界中的分布極為廣泛 Ubiquitous microbes在人類及其它高等生物難以生活的環(huán)境中有些微生物仍然可以正常生活 微生物的種類多 以真菌為例： 目前已經(jīng)定名的真菌的有十幾萬(wàn)種 每年世界上不斷有許多新種被發(fā)現(xiàn) 據(jù)估計(jì)，自然界的真菌資源有150萬(wàn)種以上 Diverse species 微生物

15、的繁殖快、易培養(yǎng) 大腸桿菌（牛乳基質(zhì)）繁殖一代12.5min，一晝夜能繁殖115代，數(shù)量可增殖到4.151034個(gè)，干菌體重量可達(dá)約1016噸 具強(qiáng)大的合成能力，可利用農(nóng)產(chǎn)品廢棄物、石油甚至CO2等為原料合成有機(jī)物。 微生物合成蛋白質(zhì)的速度比植物快500倍，比動(dòng)物快2000倍。 微生物繁殖速度快這一特性給動(dòng)植物疫病的防治，食品的防腐、保鮮等帶來(lái)了巨大的困難。 微生物的遺傳特性易發(fā)生變化 個(gè)體結(jié)構(gòu)簡(jiǎn)單，容易受到環(huán)境變化的影響而引起遺傳性發(fā)生變異 細(xì)菌自發(fā)突變的頻率為1O-8左右 各種物理、化學(xué)因子處理微生物可以促進(jìn)微生物變異 容易通過(guò)基因工程獲得變異性較大的菌種微生物學(xué)建立的社會(huì)背景 19世紀(jì)中

16、期，歐洲工業(yè)、農(nóng)業(yè)規(guī)?；a(chǎn)方式已經(jīng)形成 當(dāng)時(shí)工農(nóng)業(yè)生產(chǎn)發(fā)展中出現(xiàn)的葡萄酒發(fā)酵酸敗、人畜傳染病等與微生物相關(guān)的問(wèn)題急需解決 杰出科學(xué)家巴斯德、柯赫等科學(xué)家的貢獻(xiàn) The science of microbiology did not start until the invention of the microscope in the mid 16th century and it was not until the late 17th century that Robert Hooke and Antoine van Leeuwenhoek made their first records o

17、f fungi, bacteria and protoz-oa. The late 19th century was the time when the first real breakthroughs on the role of microbes in the environment and medi -cine were made. Louis Pasteur disproved the theory of sponta-neous generation, (that living organisms spontaneously arose from inorganic material

18、) and Robert Kochs development of pure culture techniques allowed him to show unequivocally that a bacterium was responsible for a particular disease. Since then the science has grown dramatically as microbiology impinges on all aspects of life and the environment.Formation and development of microb

19、iology 考古研究表明，我國(guó)在8000多年前的新石器時(shí)代早期就出現(xiàn)了利用微生物的“曲蘗釀酒” 我國(guó)商代釀酒技術(shù)已有很大的發(fā)展，已逐漸從農(nóng)業(yè)中分化出來(lái)成為獨(dú)立的手工業(yè)，出現(xiàn)了一些釀酒工場(chǎng)我國(guó)古代的各種酒器leeuwenhoek安東列文虎克（Antony ven Leeuwenhoek, 16321723）在1680年前后發(fā)現(xiàn)了自然界中存在的細(xì)菌、酵母菌、原生動(dòng)物等微小生物。 1676年荷蘭人列文虎克用自磨鏡片，創(chuàng)造了一架能放大266倍的原始顯微鏡檢查了污水、齒垢、糞便等，發(fā)現(xiàn)了許多肉眼看不見(jiàn)的微小生物，正確描述了微生物的形態(tài)有球形、桿狀和螺旋樣，為微生物的存在提供了科學(xué)依據(jù)。Bright f

20、ield microscopecondenserLight sourceMechanical stageeyepieceObjective lenstubebinocular microscope杰出科學(xué)家的貢獻(xiàn) 法國(guó)化學(xué)家、微生物學(xué)家路易巴斯德（Louis Pasteur，18221895） Pasteur (Louis Pasteur,18221895)首先實(shí)驗(yàn)證明有機(jī)物發(fā)酵和腐敗是由微生物引起，而酒類變質(zhì)是因污染了雜菌所致。自此，微生物學(xué)成為一門(mén)獨(dú)立學(xué)科。成功研制雞霍亂、炭疽和狂犬病疫苗。德國(guó)科學(xué)家柯赫（Robert Koch，18431910） 揭示了傳染病的本質(zhì) 建立了微生物分離、接

21、種 、培養(yǎng)的方法 Robert Kochs original micrographs of anthrax bacillus （炭疽桿菌） (Robert Koch,18431910)創(chuàng)用固體培養(yǎng)基，使有可能將細(xì)菌從環(huán)境或病人排泄物等標(biāo)本中分離成為純培養(yǎng)，利于對(duì)各種細(xì)菌的特性分別研究。他還創(chuàng)用了染色方法和實(shí)驗(yàn)動(dòng)物感染，為發(fā)現(xiàn)多種傳染病的病原菌提供實(shí)驗(yàn)手段。郭霍法則：1.特殊的病原菌應(yīng)在同一疾病中查見(jiàn)，在健康人中不存在；2.該病原菌能被分離培養(yǎng)得純種；3.該純培養(yǎng)物接種至易感動(dòng)物，能產(chǎn)生同樣病癥；4.自人工感染的實(shí)驗(yàn)動(dòng)物體內(nèi)能重新分離得該病原菌純培養(yǎng)。 For some diseases it

22、is very easy to identify the causative agent and establish how it causes disease. The symptoms of cholera, for example, can be clearly explained by the presence of the organism Vibrio cholera in the gut and the production of a toxin which causes the secretion of copious amounts of water from the gut

23、 (Topic F6). For other diseases, the cause and effect relationship may not be as clear. For example, Helicobacter pylori has only recently been accepted as the cause of many gastric ulcers as it was believed for a long time that bacteria could not survive in the stomach.Traditionally, the relationsh

24、ip between a bacterium and a disease has been established if the bacterium fulfills a number of criteria laid down by Robert Koch in the late 1800s:Kochs postulates The bacteria should be found in all cases and at all sites of the disease.在一切患病動(dòng)物和所有患病部位都能發(fā)現(xiàn)該種病原菌2. The bacteria should be isolated fro

25、m the infected person and maintained in pure culture. 細(xì)菌應(yīng)從受感染的患體中分離出來(lái)，并被培養(yǎng)為純培養(yǎng)物 3. The pure cultured microbe should cause symptoms of the disease on inoculation into a susceptible individual.純培養(yǎng)物接種到某個(gè)未經(jīng)免役者的體內(nèi)時(shí)，應(yīng)出現(xiàn)病癥。4. The bacteria should be reisolated from the intentionally infected host.細(xì)菌應(yīng)從這種人為的受

26、感染者體內(nèi)重新分離出來(lái)。Kochs postulates In practice, in many cases it has proved difficult to fulfill all of these criteria. Pure culture of bacteria in the laboratory has often been a problem. Although we are fairly certain that Mycobacterium leprae（麻風(fēng)分支桿菌） is the cause of leprosy, it has yet to be cultured i

27、n laboratory medium, and has so far been cultured only in an animal model. In the case of an intestinal disease called Whipples disease（惠普爾?。? the bacterial agent responsible has only been discovered using modern polymerase chain reaction (PCR)-based DNA detection method. Criteria 3 and 4 of Kochs p

28、ostulates are also difficult to meet if no animal model for the disease is available or there is a lack of human volunteers. A modern-day modification of these postulates(法則) is now being used to establish if a particular virulence factor is necessary for the production of an infection. Potential vi

29、rulence factors（可能的致病力因子） are first identified, then removed by mutation or replaced by cloning and the microbe is then tested for virulence. In this way a clear understanding of the disease process of a number of microorganisms has been obtained.(Edward Jenner,17491823)首創(chuàng)用牛痘預(yù)防天花，為預(yù)防醫(yī)學(xué)開(kāi)辟了廣闊途徑。(Josep

30、h Lister,18271912)首創(chuàng)用石炭酸噴灑手術(shù)室和煮沸手術(shù)用具以防術(shù)后感染，為防腐、消毒，以及無(wú)菌操作奠定了基礎(chǔ)。Watson and ClickThe development of microbiology need your participatingObscure （prehistory）period 朦朧階段史前期（約8000年前1676）Morphological （primary）period 形態(tài)描述階段初期（ 1 6761861）Physiological （foundation）period 生理水平研究階段奠基期（ 18611897 ） Mordern times

31、 現(xiàn)代微生物學(xué)時(shí)期biochemical （develomental）period 生化水平研究階段發(fā)展期（18971953）Molecular biological（maturation） 分子生物學(xué)水平研究階段成熟期（1953至今）Formation and development of microbiology微生物學(xué)的形成和發(fā)展微生物學(xué)經(jīng)驗(yàn)時(shí)期實(shí)驗(yàn)微生物學(xué)時(shí)期現(xiàn)代微生物學(xué)時(shí)期微生物學(xué)的發(fā)展過(guò)程三、近代微生物學(xué)的發(fā)展 微生物學(xué)研究工具的不斷改進(jìn) 社會(huì)和經(jīng)濟(jì)發(fā)展有大量的微生物學(xué)問(wèn)題迫切需要解決 微生物學(xué)和其他生物科學(xué)共同發(fā)展，互相促進(jìn)Food microbiologyDefenition

32、：Food microbiology is a science specializing in the relationship between food and microorganisms。 食品微生物學(xué)是專門(mén)研究微生物與食品之間相互關(guān)系的一門(mén)科學(xué)。Relationship with other subjects: As an important branch of microbiology，it is a comprehensive subject syncretized food related parts from general microbiology and industria

33、l，medical，agricultural microbiology . At the same time mixed the associated knowledge of biochemistry, mechanics and chemical engineering. 它是微生物學(xué)的一個(gè)重要分支，是一門(mén)綜合性的學(xué)科，它融合了普通微生物學(xué)、工業(yè)微生物學(xué)、醫(yī)學(xué)微生物學(xué)、農(nóng)業(yè)微生物學(xué)與食品有關(guān)的部分，同時(shí)又滲透了生物化學(xué)、機(jī)械學(xué)和化學(xué)工程有關(guān)的內(nèi)容.定義及與其他課程的關(guān)系Curriculum character： is the basic courses for the specialty

34、of food science and engineering. The aim of it is to lay the firm microbiological foundation for the students of food specialty and ensure them to skillfully master the related skills. 食品微生物學(xué)是食品科學(xué)與工程專業(yè)的專業(yè)基礎(chǔ)課，學(xué)習(xí)這門(mén)課程的目的是為食品專業(yè)的學(xué)生打下牢固的微生物學(xué)基礎(chǔ)和熟練的食品微生物學(xué)技能 Food microbiology課 程 性 質(zhì) Researches about food mic

35、robiology includes:Activity rules about food related microbesHow to utilize the beneficial microbes to manufacture food stuff for humanHow to control the harmful microbes to prevent the spoilage and deterioration of foodStudy the detective methods for food born microorganisms, set down the microorga

36、nism parameter in food, offer the guide for the judge of the food sanitation condition 研究?jī)?nèi)容包括：研究與食品有關(guān)的微生物的活動(dòng)規(guī)律；研究如何利用有益微生物為人類制造食品研究如何控制有害微生物，防止食品發(fā)生腐敗變質(zhì)；研究檢測(cè)食品中微生物的方法，制定食品中微生物指標(biāo)，從而為判斷食品的衛(wèi)生質(zhì)量而提供科學(xué)依據(jù) Food microbioligy研 究 內(nèi) 容 在食品生產(chǎn)、加工、儲(chǔ)存、運(yùn)輸、銷售等各個(gè)環(huán)節(jié)中涉及的微生物類型及形態(tài)特征 細(xì)菌 放線菌 酵母菌 霉菌 病毒 食品相關(guān)微生物的生物學(xué)特性 生理特性 遺傳特性

37、生態(tài)學(xué)特點(diǎn)二、微生物引起的食品腐敗變質(zhì)現(xiàn)象及其機(jī)理 微生物引起各類食品的變質(zhì)現(xiàn)象 微生物引起食品變質(zhì)相關(guān)的內(nèi)因、外因及其相互的聯(lián)系 微生物引起食品腐敗變質(zhì)的機(jī)理。三、微生物相關(guān)的食品安全問(wèn)題食品相關(guān)的細(xì)菌性食物中毒、食源性傳染病、真菌毒素中毒癥等 食源性疾病的微生物的特性，生長(zhǎng)、產(chǎn)毒的條件，致病的機(jī)理及預(yù)防措施四、 防止食品腐敗變質(zhì)的方法防止食品腐敗變質(zhì)常用的方法 各類方法的適用范圍、效果、影響因素 各類方法對(duì)食品品質(zhì)的影響及可能的毒性五、食品微生物的檢驗(yàn)技術(shù)研究檢測(cè)食品微生物的技術(shù) 類群 數(shù)量 有毒代謝產(chǎn)物 研究監(jiān)測(cè)食品品質(zhì)變化的方法 根據(jù)食品中微生物的存在量、種群及其他相關(guān)特征的變化監(jiān)測(cè)食

38、品的品質(zhì)，進(jìn)行早期的微生物危害預(yù)測(cè)、預(yù)防六、微生物在食品工業(yè)中的應(yīng)用 微生物的對(duì)食品的轉(zhuǎn)化作用 微生物合成的代謝產(chǎn)物 初生代謝產(chǎn)物 次生代謝產(chǎn)物 微生物酶制劑 微生物細(xì)胞 食品微生物學(xué)研究的內(nèi)容包括與食品有關(guān)的微生物的特征、微生物與食品的相互關(guān)系及其生態(tài)條件等，所以從事食品科學(xué)的人員應(yīng)該了解微生物與食品的關(guān)系。一般來(lái)說(shuō)，微生物既可在食品制造中起有益作用，又可通過(guò)食品給人類帶來(lái)危害。我國(guó)幅員遼闊，微生物資源豐富。開(kāi)發(fā)微生物資源，并利用生物工程手段改造微生物菌種，使其更好地發(fā)揮有益作用，為人類提供更多更好的食品，是食品微生物學(xué)的重要任務(wù)之一。食品微生物學(xué)工作者應(yīng)該設(shè)法控制或消除微生物對(duì)人類的這些有

39、害作用；采用現(xiàn)代的檢測(cè)手段，對(duì)食品中的微生物進(jìn)行檢測(cè)，以保證食品安全性，這也是食品微生物學(xué)的任務(wù)之一。總之，食品微生物學(xué)的任務(wù)在于，為人類提供既有益于健康、營(yíng)養(yǎng)豐富，而又保證生命安全的食品。Food microbiology Food microbiologyTask:1. Exploit and modify the microbiology resources ,make full use of its beneficial side in food making, therefore provide people with plentiful ,nutritional and functional health food.2. Try to minimize its harmful side ,th