Microbial World and You

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Microbial World and You

• What did the male bacteria say to the female
  bacteria?
• Who needs biology when we have chemistry.

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What is Microbiology?

• Micro - too small to be seen with the naked eye
• Bio - life
• ology - study of

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Organisms included in the study of Microbiology

• 1. Bacteria
• Bacteriology
• 2. Protozoans
• Protozoology
• 3. Algae
• Phycology

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• 4. Parasites
• Parasitology
• 5. Yeasts and Molds
• Mycology
• Fungi
• 6. Viruses
• Virology

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5 Characteristics of Life

• 1. Cells
• 2. Maintain structure by taking up chemicals and
  energy from the environment
• 3. Respond to stimuli in the external environment
• 4. Reproduce and pass on their organization to
  their offspring
• 5. Evolve and adapt to the environment

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Physical Requirements

• Temperature
• psychrophiles (cold loving microbes)
• range 0 C - 20 C
• mesophiles (moderate temp. loving microbes)
• range 20 C - 40 C
• thermophiles (heat loving microbes)
• range 40 C - 100 C

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pH

• Most bacteria grow between pH 6.5 - pH 7.5
• Very few can grow at below pH 4.0
• many foods, such as sauerkraut, pickles, and
  cheeses are preserved from spoilage by acids
  produced during fermentation

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Bacterial Growth - increase in the of cells

• Binary Fission
• Generation Time (Doubling Time)
• time required for a cell to divide
• most about 1 Hr. To 3 Hrs.
• E. coli - 20 minutes
• Mycobacterium tuberculosis - 24 Hrs.

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Binary Fission - unchecked

• E. coli - generation time of 20 min.
• 20 generations (about 7 hrs.)
• 1 million cells
• 30 generations ( about 10 hrs.)
• 1 billion cells
• 72 generations ( about 24 hrs.)
• 1 x 1021
• 1,000,000,000,000,000,000,000
• cells

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Limiting factors in the environment

• Lack of food, water or nutrients
• space
• accumulation of metabolic wastes
• lack of oxygen
• changes in pH
• temperature

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Phases of Growth

• 4 Phases
• 1. Lag Phase
• 2. Log Phase
• 3. Stationary Phase
• 4. Death Phase

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1. Lag Phase

• Bacteria are first introduced into an environment
  or media
• Bacteria are checking out their surroundings
• cells are very active metabolically
• of cells changes very little
• 1 hour to several days

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2. Log Phase

• Rapid cell growth (exponential growth)
• population doubles every generation
• microbes are sensitive to adverse conditions
• antibiotics
• anti-microbial agents

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3. Stationary Phase

• Death rate rate of reproduction
• cells begin to encounter environmental stress
• lack of nutrients
• lack of water
• not enough space
• metabolic wastes
• oxygen
• pH

Endospores would form now
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4. Death Phase

• Death rate gt rate of reproduction
• Due to limiting factors in the environment

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Bacteria - what comes to mind?

• Diseases
• Infections
• Epidemics
• Food Spoilage

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When in fact

• Only 1 of all known bacteria cause human
  diseases
• About 4 of all known bacteria cause plant
  diseases
• 95 of known bacteria are non-pathogens
• http//www.youtube.com/watch?vIekdfJ-7Zyksafety_
  modetruepersist_safety_mode1safeactive

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Microbes Benefit Humans

• 1.Bacteria are primary decomposers - recycle
  nutrients back into the environment (sewage
  treatment plants)

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They produce various food products

• cheese, pickles, sauerkraut, green olives
• yogurt, soy sauce, vinegar, bread
• Beer, Wine, Alcohol

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3. Microbes are used to produce Antibiotics

• Penicillin
• Mold
• Penicillium notatum
• 1928 Alexander Fleming

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4. Bacteria synthesize chemicals that our body
needs, but cannot synthesize

• Example E. coli
• B vitamins - for metabolism
• Vitamin K - blood clotting
• Escherichia coli
• Dr. Escherich
• Colon (intestine)

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5. Competitive Exclusion

• Our normal microbial flora prevents potential
  pathogens from gaining access to our body

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6. Bioremediation

• Using microbes to clean up pollutants and toxic
  wastes
• Exxon Valdez - 1989
• 2 Genera
• Pseudomonas sp.
• Bacillus sp.

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7. Recombinant DNA Technology Gene
Therapy Genetic Engineering

• Bacteria can be manipulated to produce enzymes
  and proteins they normally would not produce
• Insulin
• Human Growth Hormone
• Interferon

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8. Microbes form the basis of the food chain

• Marine and fresh water microorganisms

http//www.youtube.com/watch?vTHRgkllfj1Asafety_
modetruepersist_safety_mode1safeactive
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Microbes do benefit us, but they are also capable
of causing many diseases

• Pneumonia Whooping Cough
• Botulism Typhoid Fever Measles
• Cholera Scarlet Fever Mumps
• Syphilis Gonorrhea Herpes 1
• Chlamydia Tuberculosis Herpes 2
• Meningitis Tetanus RSV
• Strep Throat Lyme Disease AIDS
• Black Plague Diarrhea Gangrene
• bacteria, virus

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Spontaneous Generation

• Theory that life just spontaneously developed
  from non-living matter
• Example
• toads, snakes and mice - moist soil
• flies and maggots - manure and decaying flesh

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Experiments to disprove Spontaneous Generation

• Francesco Redi
• 1668
• Rudolph Virchow 1858
• Theory of Biogenesis
• Cells can only arise from preexisting cells
• Louis Pasteur 1861

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Pasteur designed special swan-necked flasks
with a boiled meat infusion
Shape of flask allowed air in (vital force) but
trapped dust particles which may contain microbes
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Germ Theory of Disease

• Hard for people to believe that diseases were
  caused by tiny invisible wee animalcules
• Diseases, they thought, were caused by
• demons
• witchcraft
• bad luck
• the wrath of God
• curses
• evil spirits

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Kochs Postulates

• 1. The same organisms must be found in all cases
  of a given disease.
• 2. The organism must be isolated and grown in
  pure culture.
• 3. The isolated organism must reproduce the same
  disease when inoculated into a healthy
  susceptible animal.
• 4. The original organism must again be isolated
  from the experimentally
• infected animal.

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Exceptions to Kochs Postulates
Mycobacterium leprae
Leprosy
Never been grown in pure culture on artificial
media
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Koch established the Microbial Origins of 3
important diseases of his day

• 1. Cholera (fecal-oral disease)
• Vibrio cholerae
• 2. Tuberculosis (pulmonary infection)
• Mycobacterium tuberculosis
• 3. Anthrax (sheep and cattle)
• Bacillus anthracis

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Golden Age of Microbiology 1857 - 1914

• Pasteur
• Pasteurization
• Fermentation
• Joseph Lister
• Phenol to treat surgical wounds 1st attempt to
  control infections caused by microoganisms
• Robert Koch
• Kochs Postulates
• Edward Jenner
• vaccination
• Paul Erlich
• 1st synthetic drug used to treat infections
• Salvarsan - arsenic based chemical to treat
  Syphilis
• salvation from Syphilis

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Bacterial Morphology

• Bacilli
• Cocci
• Spiral

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Arrangements

• Diplo
• Strepto
• Staphylo
• Tetrad
• Vibrio comma shaped
• bacter bacilli
• bacterium bacilli

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• Staphylococcus aureus
• Staphylococcus epidermidis
• Streptococcus pneumoniae
• Vibrio cholerae
• Rhodospirillium rubrum
• Bacillus subtilis
• Micrococcus luteus

• Bacillus anthrasis
• Streptococcus pyogenes
• Steptococcus lactis
• Streptococcus faecalis
• Campylobacter jujuni
• Helicobacter pylori
• Enterobacter aerogenes