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Microorganisms

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aggregations or colonies can be seen without the aid of a ... Linen fabric is made from flax stems. Stems are immersed in water ... Linen Fabric Production ... – PowerPoint PPT presentation

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Title: Microorganisms


1
Microorganisms
2
Microbes
  • too small to be seen with the naked eye
  • aggregations or colonies can be seen without the
    aid of a microscope

3
Microbes
  • are found almost anywhere
  • are more abundant than any other life form
  • they are forms on which all others depend.

4
Recycle elements required for life
  • N - Nitrogen
  • O - Oxygen
  • P - Phosphorus
  • S - Sulfur
  • C - Carbon

5
Microbes produce
  • food
  • fuel
  • air

6
4 major categories
  • bacteria
  • fungi
  • protists
  • viruses

7
Pathogens
  • disease causing agents
  • AIDS - Acquired Immune Deficiency Syndrome
  • Botulism - food poisoning
  • Tuberculosis
  • Polio

8
Pathogens
  • Typhoid FeverSyphilis

9
Disease
  • Microbes cause disease by directly damaging
    tissues and weakening bodily functions or by
    producing toxins that do.

10
Pathogenic microbes
  • the proportion of pathogenic microbes on earth is
    very small

11
Producers
  • produce carbohydrates
  • break down starch into sugar
  • convert sugars into alcohol

12
Water Dwelling microbes
  • algae and bacteria
  • largest producers of carbon containing compounds
    through photosynthesis

13
Some microbes
  • are unable to take in Carbon Dioxide from the
    air.
  • They get Carbon from bicarbonate in the water

14
Ion
  • an atom that carries a positive () or a negative
    (-) charge
  • carries the charge because it has gained or lost
    one or more electrons

15
Microbes use CHOs (carbohydrates)
  • synthesized during photosynthesis (Ps) to make
    cell structures and as an energy source
  • Provide food for larger organisms
  • Replenish Oxygen supply

16
Single Celled Fungi
  • Yeasts
  • Producers in wine making, bread baking or beer
    brewing.
  • Convert sugar to alcohol in fermentation process

17
Cheese Making
  • bacteria convert lactose (milk sugar) to lactic
    acid

18
Contribute to production
  • of food and other substances by their enzymes

19
Enzymes
  • organic molecules that speed up biochemical
    reactions without being used up or becoming part
    of the end product.
  • A catalyst - causes a reaction to take place

20
Examples
  • foods
  • medicines
  • vitamins
  • leather processing
  • textile production

21
Decomposers and Recyclers
  • worlds greatest recyclers
  • Keep elements like C and N cycling through the
    environment
  • Used to treat sewage, clean up toxic wastes,
    processing materials

22
Recyclers
  • more than one type of bacterium is needed to
    convert atmospheric N into a form useable by
    plants.
  • Requires three different chemical reactions.

23
Production through decomposition
  • Methane - decomposition of organic matter
  • Methanogens - swampy areas, land fills, digestive
    tract of ruminants.

24
Production through decomposition
  • Linen fabric is made from flax stems
  • Stems are immersed in water
  • Bacterium digests pectin that makes the stalks
    stiff

25
Linen Fabric Production
  • remainder is washed dried and spun into thread
    and then woven into fabric

26
Basic features of MOs (microorganisms)
  • 4 major groups
  • bacteria, fungi, protists, viruses
  • Viruses are not made up of cells and are not
    considered organisms by many microbiologists.

27
Bacteria, fungi and protists
  • have a cellular structure, a membrane surrounding
    cytoplasm

28
Protists
  • have an inner compartment nucleus
  • DNA in non circular chromosomes
  • unicellular or multicellular
  • protozoans, algae, others resemble fungi

29
Fungi
  • have cellular structure
  • non circular chromosomes
  • in fungi with many cells, walls between cells are
    sometimes not complete
  • cytoplasm and nuclei can stream from one cell to
    another within slender filaments of cells called
    hyphae

30
Fungi
  • have cellular structure
  • non circular chromosomes
  • in fungi with many cells, walls between cells are
    sometimes not complete

31
Fungi
  • cytoplasm and nuclei can stream from one cell to
    another within slender filaments of cells called
    hyphae

32
Yeasts
  • unicellular

33
Molds
  • have many cells

34
Fungi
  • visible to the naked eye
  • mushrooms
  • bracts
  • puffballs
  • toadstools

35
Viruses
  • not cellular
  • particles made up of nucleic acid and protein
  • Include short length of DNA or RNA - never both!

36
Viruses
  • On their own they cannot reproduce at all
  • Inject their nucleic acid into a host cell

37
Viruses
  • Injected DNA or RNA tricks host cell into using
    the viruses chemical instructions to make
    substances needed for the virus to reproduce

38
Viruses
  • Host cell is damaged when newly reproduced virus
    particles break out of cell (lyse)

39
What does it take to keep a microbe alive?
  • Lots of variation in environmental and
    nutritional condition requirements

40
Nutritional needs
  • energy sources
  • basic elements to make and replace cell structures

41
Heterotrophs
  • organic compounds to meet energy needs
  • Carbon source to make own organic molecules
  • get energy from sugars, starches, fats and other
    organic compounds

42
Saprobes
  • live in soil, get nutrients from dead organic
    matter
  • Clostridium botulinum - botulism, food poisoning

43
Autotrophs
  • build their own organic compounds if they have an
    available source of inorganic compounds

44
Phototrophs
  • generate their own food using sunlight and
    inorganics such as carbon dioxide

45
Chemotrophs
  • dont require sun
  • get energy from carbon dioxide, salts, water and
    others

46
Nitrosomonas bacteria
  • live in soil
  • use ammonia (NH4) as energy

47
hetero, chemo and phototrophs
  • use energy from the environment
  • light and heat energy from the sun
  • energy stored in chemical bonds or organic or
    inorganic compounds

48
Six major elements in cells
  • C - Carbon
  • H - Hydrogen
  • N - Nitrogen
  • O - Oxygen
  • P - Phosphorus
  • S - Sulfur

49
Also -
  • K- potassium
  • Ca - Calcium
  • Fe - Iron
  • Na - Sodium

50
Trace elements
  • Co - Cobalt
  • Zn - Zinc
  • Mo - Molybdenum
  • Cu - Copper
  • Mn - Manganese
  • Si - Silicon

51
hetero, chemo, and phototrophs
  • some require organic compounds that they cannot
    make themselves
  • must be added to culture in isolation - called
    growth factors
  • Vitamins

52
Microbial nutrition in the lab
  • hardened gel - called agar
  • nutrients are added to the agar
  • called growth medium

53
Pure Cultures
  • Grow only one kind of microbe
  • Must use aseptic technique to avoid contaminating
    the culture

54
Mixed cultures
  • may be grown on selective media
  • nutritious to some and not to others
  • allows researchers to isolate a certain species
    of microbe

55
Environmental conditions for microbial growth
  • Oxygen - require Oxygen - aerobic
  • some microbes live in Oxygen poor environment -
    anaerobic

56
Anaerobic processes
  • fermentation
  • O2 atoms in compounds are rearranged and made
    available to microbes

57
Anaerobes
  • made up of molecules containing O2 but dont
    produce free or gaseous O2

58
Anaerobes
  • free oxygen may be toxic

59
pH
  • favorable range - 6-8
  • acidophillic - acid loving used in mining
    operations.
  • Oxidize Cu, Fe and other metal sulfides in the
    process of pulling out the ore

60
Temperature
  • 37 degrees C (98 degrees F)
  • some can survive a wide range of temps ranging
    from 32 degrees F to 212 degrees F

61
Moisture
  • dissolve minerals, ions, gases and organic
    compounds

62
Moisture
  • in extremely dry conditions microbes form spores
    that hold the genetic information and some
    cytoplasm.

63
Spores
  • when moisture is added the spore breaks down and
    bacteria resume their normal activity

64
Salt concentrations
  • most microbes cant survive in high salt or sugar
    concentrations

65
Microbe sex
  • or - how microbes reproduce
  • process is known as binary fission

66
Binary fission
  • increase in size, extend cell wall material down
    center and divide in two.

67
Speed of reproduction
  • in 24 hours some species of bacteria can go from
    one cell to 16,777,216 cells

68
Single celled protists
  • have a more difficult reproductive process
  • DNA in nucleus is fist replicated then divided
    into 2 identical sets (mitosis)

69
continued
  • cytoplasm of cell then divides to form 2
    identical daughter cells.

70
Fungi
  • reproduce by a number of methods
  • yeasts - budding - cytoplasm pinches off on one
    side of cell to form a new cell
  • or fuses with another cell

71
Fungi
  • after fusing with a cell, nuclei fuse and divide
    to form spores when released from the cell

72
Yeast
  • spores become cells on their own

73
Many celled fungi
  • hyphae or filaments fuse to form sporagia
  • cases in which nuclei from 2 parent molds
    excahange pieces of chromosomes
  • a type of sexual reproduction

74
Microbial populations
  • can and do change over time
  • bacterial populations adapt to changes in the
    environment

75
Mutations
  • change in DNA
  • alteration of base sequence
  • occur spontaneously

76
Genetic recombination
  • exchanging or recombining genetic information
  • two bacterial cells become connected by a thin
    strand of cell material called a pilus

77
Genetic recombination
  • DNA can travel from one microbe to another
  • gene enters a microbe that did not initially have
    it
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