Introduction to Microbiology PDF

Official (Closed) and Non- Sensitive INTRODUCTION to MICROBIOLOGY Official (Closed) and Non- Sensitive ToDaY’s MeNu: Overview: Definition Introduction...

Official (Closed) and Non- Sensitive INTRODUCTION to MICROBIOLOGY Official (Closed) and Non- Sensitive ToDaY’s MeNu: Overview: Definition Introduction Members of the Microbial world History Human’s Perspective Microorganisms: the environment & industries 2 Official (Closed) and Non- Sensitive Overview: What is Microbiology? Definition of Microbiology Microbiology is the study of microorganisms. This includes eukaryotes e.g. fungi, protists and Living things helminths (worms), and prokaryotes e.g bacteria & archaea. Non -living And viruses thing Greek (mīkros, "small"; bios, "life"). Definition of micro – below the resolution of the We can see human eyes up to ~ 0.1 Official (Closed) and Non- Sensitive Microorganisms – Introduction Microorganisms are foundation for all life on Earth: watch video on how life began: https://www.biologyonline.com/tutorials/origins-of-life-on-earth Have existed for ~3.5 billion years Plants, animals, modern microorganisms all evolved form ancestral bacteria Where can they be found? Found in all environments : varying in temperature, oxygen levels, pH. Can survive in extreme environments – extremophiles Numbers Bacterial species outnumber mammalian species by factor of 10,000! Less than 1% of all microbial species can be grown and studied in laboratory – hard to mimic conditions for their growth Size (bacteria) Around ~1um; Smallest is Mycoplasma sp: ~ 0.3um Largest isThiomargarita magnifica ~ 1cm Visible to naked eye over 5000 times bigger than the average microbe. Source: Image © Tomas Tyml/The Regents of the University of California, Lawrence Berkeley 4 Official (Closed) and Non- Sensitive https://www.weforum.org/agenda/2020/10/covid-19-coronavirus-disease-size-compairson-zika-health-air-pollution/ Official (Closed) and Non- Sensitive Members of the microbial world Bacteria, Archaea, Fungi, Protists, Virus, Helminths. 6 Official (Closed) and Non- Sensitive Overview: Members of the microbial 1. 2. world Cells and Organization Energy Use & Metabolism 3. Response to Environmental Changes 4. Regulation & Homeostasis 5. Reproduction 6. Growth & Development 7. Biological Evolution Kingdom Classification still has grey zones : Characteristics Major groups of microorganisms Virus - requires living ‘host’ of Prokaryotes Prokaryotes: Eubacteria & Archaea Eukaryotes: Fungi; Protists (algae & protozoans) to reproduce vs eukaryotes Virus has no cells – Viruses (non-living) acellular Inactive outside host * Helminths – parasites - classified as animals. 7 Official (Closed) and Non- Sensitive Microorganisms: Prokaryotes: Bacteria & Archaea Bacteria Archaea Single-celled prokaryotes single-celled prokaryotes Shapes (spherical, rod, spiral) Similar shapes, sizes, & appearances to bacteria Multiply via binary fission Multiply via binary fission Some are motile : flagella Some are motile : flagella Cell wall contains peptidoglycan (unique to bacteria) Cell wall lack peptidoglycan: different chemical composition from bacteria. Cell membrane composition different Many are extremophiles: (T, pH, pressure) etc E.g Extreme halophiles – tolerate extreme salt conc Extreme thermophiles (hyperthermophiles) – optimum T = 85oC So far – do not cause diseases to humans Bacterial cell wall = peptidoglycan Archaea cell wall = no peptidoglycan Source: Let’s talk science: https://letstalkscience.ca/educational- 8 Official (Closed) and Non- Sensitive Microorganisms- Eukaryotes: Fungi and Protista Fungi single-celled - yeast multicellular - hyphae & mycelia: mould Yeast multiply - budding; mould- spores Non motile Some are dimorphic : exist in both yeast & hyphal form. E.g in human body temp – yeast; in room temp - mould Cell wall contains chitin Yeast - unicellular Aspergillus sp– multicellular 9 Official (Closed) and Non- Sensitive Microorganisms- Eukaryotes: Fungi and Protista Fungi Protista Single-celled or multicellular eukaryotes Single-celled or multicellular eukaryotes Hyphae & mycelia Very diverse group in terms of size, mode Yeast multiply - budding; mould- spores of nutrition and motility Non motile Plant – like, animal – like or fungal- like Some are dimorphic : exist in both yeast Plasmodium sp – malarial parasite & hyphal form. E.g in human body temp – Most do not have cell wall kelp yeast; in room temp - mould Cell wall contains chitin Amoeba - heterotrophs algae - autotrophs Anopheles sp Yeast - unicellular Aspergillus sp– multicellular http:// www.newworldencyclopedia.org/ entry/Image:Chaos_diffluens.jpg Pseudopodia or pseudopod = temporary Plasmodium sp projections of the cytoplasm; for motility 10 Official (Closed) and Non- Sensitive Microorganisms- Eukaryotes: Helminths* *Helminths Are multicellular - classified as animals Animal parasites e.g tape worm, round worms. Not strictly microorganisms - some visible to human eyes; At some stage in their life cycle they are microscopic in size Medically important Traditionally they are studied under Various microbiology eggs 11 Official (Closed) and Non- Sensitive Members of the microbial world: Virus 140,000 viral species living in the human gut, more than half of which have never been seen before More than 200 known virus sp known to infect humans Virus is NOT a living thing Cannot make proteins No cells No metabolism https://www.nationalgeographic.com/science/article/factors-allow-viruses-infect-humans-coronavirus Cannot reproduce / replicate by themselves Viruses are simply genetic information (DNA or RNA) - contained within protective coat 12 Official (Closed) and Non- Sensitive Virus that infect Members of the microbial world: Virus bacteria 140,000 viral species living in the human gut, more than half of which have never been seen before More than 200 known virus sp known to infect humans Virus is NOT a living thing Cannot make proteins No cells No metabolism https://www.nationalgeographic.com/science/article/factors-allow-viruses-infect-humans-coronavirus Cannot reproduce / replicate by themselves Viruses are simply genetic information (DNA or RNA) - contained within protective coat The World Health Organization (WHO) named the novel coronavirus that causes the disease COVID-19 “severe acute respiratory syndrome coronavirus 2” (SARS-CoV-2) in January 2020 13 Official (Closed) and Non- Sensitive Members of the microbial world: Virus u se n we e Ca thes es? ? h ag tions Source image: PNAS p ca p p li Image credit: Science A Source/Lee D. Simon: Bacteriophages attacking Escherichia coli 14 Official (Closed) and Non- Sensitive Overview: Members of the microbial world Important to know the different types of microorganisms – why? Medical field : to treat a patient who has bacterial or viral infection; the treatment will be different. Antibiotics will not work on virus or fungi. Why? Industries : to grow and cultivate bacteria or fungi for production of enzymes, amino acids etc. Will need to know the different nutritional and growth requirements of a bacteria and a fungi. What temperature, pH etc? 15 Official (Closed) and Non- Sensitive Microorganisms – Scientific Names Binomial System of Nomenclature After a scientific name has been fully mentioned once, it can be abbreviated with the initial of the Two words genus followed by the species. Full name of microbe Subsequently the (Escherichia coli) abbreviation can be when it first used (E. coli) appears In printed written form: Genus and species always italicized or underlined Escherichia coli or Escherichia coli May be abbreviated (E. coli ) In hand written form: Genus and species always underlined Escherichia coli May be abbreviated (E. coli ) 16 Official (Closed) and Non- Sensitive Microorganisms: A brief history The discovery of microorganisms… Important scientists Experiments.. 17 Official (Closed) and Non- Sensitive History: dispute over Spontaneous Generation theory Dispute over Spontaneous Generation 1670s - After Anton van Until the second half of the nineteenth century, many scientists and Leeuwenhoek discovered philosophers believed that some forms of life could arise spontaneously previously “invisible” world from nonliving matter; of microorganisms using his microscope - scientists Known as the spontaneous generation theory began to ask about the origins of these microbes. ’…frogs simply seem to appear along the muddy banks of the Nile River in Egypt during the annual flooding’’ ‘’..Maggots appeared on rotting meat’’ There were scientists who did not believe in this and contributed to disproving the idea. Francesco Redi Louis Pasteur 18 Official (Closed) and Non- Sensitive History: dispute over Spontaneous Generation theory 1 2 3 Francesco Redi’s experiment Jar 1: Open jar: maggots and flies appear Jar 2 Tightly sealed jar: no maggots and no flies on meat Jar 3: covered with netting to allow air :Flies were attracted to the smell of meat; soon there were flies and maggots on the gauze But no maggots and no flies on meat. Conclusion: Flies are necessary to produce flies and they do not arise spontaneously from rotting meat. Flies need to be in contact with the meat for the maggots to appear Source: https://www.mun.ca/biology/scarr/4270_Redi_experiment.html 19 Official (Closed) and Non- Sensitive History: dispute over Spontaneous Generation theory French chemist Louis Pasteur considered “father of modern microbiology” 1861 -conclusively disputed spontaneous generation theory through the swan-neck flask experiment ( S neck flask) Ended arguments that unheated air or broths contained “vital force” necessary for spontaneous generation Biogenesis describes the production of living things from other living things 20 Official (Closed) and Non- Sensitive History: dispute over Spontaneous Generation theory When the sterile broth touched the dust, microbes in the dust go into the broth & Air escapes from Microorganisms from open end of flask. starts to multiply. Broth becomes cloudy air settle in bend. Years Hours/days 1 Broth sterilized— 2 Broth allowed 3 Broth stays sterile 4Flasktilted so that 5 Bacteria multiply air escapes. to cool slowly— indefinitely. the sterile broth comes in broth. air enters. in contact with micro- organisms from air. Air could travel in/out of flask : it was not the air Pasteur demonstrated conclusively 21 itself that caused the contamination. Due to 1) microbial life can be destroyed by heat gravity, microbes could not move upwards and 2) methods can be devised to block access of airborne settled together with the dust at the S bend microbes to nutrient environments. Copyright © 2016 McGraw-Hill Education. Permission These discoveries form the basis of aseptic techniques used required for reproduction or display. in microbiology techniques Official (Closed) and Non- Sensitive Microorganisms & humans the good, the bad and the ugly…. 22 Official (Closed) and Non- Sensitive Microorganisms: A human Perspective To be discussed in later topics Microbes can be both GOOD or BAD Microbes that live stably in and on the human body are GOOD called the human microbiome or Some are part of our human microbiota – human microbiota microbiome or normal flora Pathogens = disease Important roles in the environment causing microbes Humans have benefitted from microbes – used them in numerous applications in industries, research, environment Anthrax as and health bioterrorism weapon BAD Some microbes cause diseases Microbes have also killed more people than have ever been killed in war Bioterrorism – potential to be misused 23 Official (Closed) and Non- Sensitive Microorganisms: A human Perspective Diseases that had major impact on humans: major pandemics Black death – bubonic plague: (bacteria) ~1/3 population of Europe died ~25 mil individuals Influenza (virus) Small pox (virus) Will there be another wave coming? 2.22 mil infected Emerging diseases : S’pore: Feb 2023 Human connectivity: Increase travel 1,700 deaths Increase contact with animals (reservoirs) Evolution of infectious agents previously unable to infect humans 672 mil infected World: Feb 2023 Reemerging diseases 6.85 mil deaths Diseases such as measles, mumps, whooping cough nearly eradicated from U.S. but could re-emerge with declining 24 Official (Closed) and Non- Sensitive Microorganisms: their role in the environment & their applications in industries the gGood, the bad and the ugly…. 25 Official (Closed) and Non- Sensitive Microorganisms & Environment Important roles in the environment that ultimately impacts humans – ensures our survival GOOD Recycling of nutrients through the biogeochemical cycles E.g carbon cycle, nitrogen cycle Oxygen production – algae/phytoplanktons are Series of processes where photosynthetic carbon from the Microbes decompose dead matter – recycle organic environment is incorporated into living carbon back into the environment organisms and then returned back to the environment as carbon dioxide 26 Official (Closed) and Non- Sensitive Microorganisms – Applications Humans have used microbes in many applications 1) Food Industries Yeast in baking bread, (Saccharomyces cerevisiae) Fermented drinks: eg milk into yoghurt : bacteria (Lactobacillus sp grapes into wine: yeast (Saccharomyces cerevisiae) 2) Environmental applications Bioremediation / biodegradation: cleaning up of oil spills ( some bacteria have metabolic pathways to breakdown hydrocarbons) Wastewater treatment 27 Official (Closed) and Non- Sensitive Microorganisms – Applications Humans have used microbes in many applications 3) Medical and Pharmaceutical industries (Biotechnology/Research) Vaccines Diagnostic kits Medications - insulin Antibiotics – penicillin by Penicillium chrysogenum Production of these medical / pharrmaceutical products require techniques in genetic engineering & biotechnology e.g: insulin produced by genetically engineered bacteria E. coli that has the gene coding for insulin. 28 Official (Closed) and Non- Sensitive Source: : http://book.bionumbers.org/how-many- virions-result-from-a-single-viral- infection/ Phage therapy New way to kill bacteria: Source: Sciencephotolibrary: https://www.sciencephoto.com/media/249796/view/coloured-sem-of- t-bacteriophages-attacking-e-coli overcome antibiotic resistance Watch video The YouTube channel "Kurzgesagt – In a Nutshell" explains how bacteriophages infect Source: and destroy in this colorful animated video https://phagesdb.org/glossary/ 29