Types of micro organisms l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 19

Types of Micro-organisms PowerPoint PPT Presentation


  • 103 Views
  • Uploaded on
  • Presentation posted in: General

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

Download Presentation

Types of Micro-organisms

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 l.jpg

Types of Micro-organisms

  • Bacteria

  • Viruses

  • Fungi

  • Protozoa


Slide2 l.jpg

  • fungi ( eg. Mucor , Rhizopus )

  • protozoa ( eg. Amoeba , Paramecium )

  • algae(unicellular / colonial form)

  • ( eg. Spirogyra )

Algae - Diatoms

Zooplankton

(some multicellular)


Useful micro organisms l.jpg

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 l.jpg

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 l.jpg

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 l.jpg

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 l.jpg

  • bacteria

    • prokaryotic cells(without nuclear membrane)

    • reproduce by binary fission

    • some are pathogenic, some are useful


Slide8 l.jpg

  • viruses

    • with only DNA/RNA + protein coat

    • all are parasitic(they are considered living only when they are inside living cells)


Harmful micro organisms9 l.jpg

Harmful Micro-organisms

  • decay food & other useful materials

    • microorganisms are saprophytic

    • take in decaying food: cause food poisoning


Antibiotics l.jpg

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 l.jpg

Antibiotics

  • Broad-spectrum antibiotics:can attack many different strains of bacteria

  • Narrow-spectrum antibioticscan attack only one or a few strains of bacteria


Antibiotics12 l.jpg

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 l.jpg

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 l.jpg

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 l.jpg

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 l.jpg

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 l.jpg

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 l.jpg

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


Slide19 l.jpg

~END~


  • Login