types of micro organisms
Download
Skip this Video
Download Presentation
Types of Micro-organisms

Loading in 2 Seconds...

play fullscreen
1 / 19

Types of Micro-organisms - PowerPoint PPT Presentation


  • 164 Views
  • Uploaded on

Types of Micro-organisms. Bacteria Viruses Fungi Protozoa. fungi ( eg. Mucor , Rhizopus ) protozoa ( eg. Amoeba , Paramecium ) algae (unicellular / colonial form ) ( eg. Spirogyra ). Algae - Diatoms. Zooplankton (some multicellular). Useful Micro-organisms. yeast

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Types of Micro-organisms' - beth


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
types of micro organisms
Types of Micro-organisms
  • Bacteria
  • Viruses
  • Fungi
  • Protozoa
slide2

fungi ( eg. Mucor , Rhizopus )

  • protozoa ( eg. Amoeba , Paramecium )
  • algae(unicellular / colonial form)
  • ( eg. Spirogyra )

Algae - Diatoms

Zooplankton

(some multicellular)

useful micro organisms
Useful Micro-organisms
  • yeast
    • carry out alcoholic fermentation in the presence of carbohydrates & the absence of O2
    • baking bread
      • produces carbon dioxide to raise the dough
    • brewing beer / making wine
      • fermentation to produce alcohol
useful micro organisms4
Useful Micro-organisms
  • nitrogen-fixing bacteria in leguminous plant[root nodules]
    • carry out nitrogen fixation which changes N2 gas from the air to nitrogenous compounds for plants to produce protein
useful micro organisms5
Useful Micro-organisms
  • decomposers & nitrifying bacteria
    • decomposers decompose organic waste & dead body into ammonia
    • nitrifying bacteria change ammonia into nitrate for plants to make protein
harmful micro organisms
Harmful Micro-organisms
  • disease causing (pathogens)
  • bacterial disease : e.g. cholera, sore throat, tuberculosis
  • viral disease : e.g. AIDS, bird flu, common cold, influenza
  • fungal disease : e.g. athlete’s foot, ringworm
  • protozoa disease : e.g. malaria, sleeping sickness

Dust Mite - multicellular

athlete\'s foot

slide7

bacteria

    • prokaryotic cells(without nuclear membrane)
    • reproduce by binary fission
    • some are pathogenic, some are useful
slide8

viruses

    • with only DNA/RNA + protein coat
    • all are parasitic(they are considered living only when they are inside living cells)
harmful micro organisms9
Harmful Micro-organisms
  • decay food & other useful materials
    • microorganisms are saprophytic
    • take in decaying food: cause food poisoning
antibiotics
Antibiotics
  • chemicals produced by microorganisms which can kill or stop the growth of bacteria & fungi
  • e.g. penicillin
  • importance:effective in treating many diseases such as meningitis, syphilis, etc
antibiotics11
Antibiotics
  • Broad-spectrum antibiotics:can attack many different strains of bacteria
  • Narrow-spectrum antibioticscan attack only one or a few strains of bacteria
antibiotics12
Antibiotics

Clear zone

- indicates the absence of bacteria which had been killed by the antibiotic

Clear zone with larger diameter indicates a more powerful antibiotic against the bacteria

food preservation
Food Preservation
  • Heating
    • kill most microorganisms & their spores by high temperature
  • Canning&Bottling
    • sealing in cans to avoid bacterial entry
    • should work together with sterilization
food preservation14
Food Preservation
  • Pasteurization
    • kill most microorganisms without changing the flavour of milk
    • 75 ℃ for 15s and then quickly cooled & bottled
  • UHT (Ultra High Temperature) treatment
    • common in killing bacteria in milk
    • superheat to ~150℃ for a few seconds and then sealed
food preservation15
Food Preservation
  • Refrigeration
    • to decrease or stop the activities & growth of microorganisms (NOT killing them)
  • Freezing
    • stop the activities of micro-organisms
    • NOT killing them
    • they can resume activity when ice melts
food preservation16
Food Preservation
  • Drying (Dehydration)
    • micro-organism dies due to water deficiency
  • Smoking
    • dry, coat with smoke which has chemical to stop bacterial growth
food preservation17
Food Preservation
  • Pickling
    • add vinegar (usually together with salt)
    • kill bacteria by acid
  • Osmoticpreservation
    • by adding salt or sugar
    • to remove water from micro-organisms by osmosis
food preservation18
Food Preservation
  • Irradiation
    • expose food to-radiation
    • kill bacteria and moulds & prevent food spoilage
  • Preservatives
    • add to food to stop bacterial growth or kill them
ad