1_Microbiologia

Size of Living Things

1 m = 100 cm = 1,000mm = 1,000,000 µm = 1,000,000,000nm

1mm = 1000 µm = 1000000nm

1 µm = 1000nm Click link for an interactive

“Size of Microscopic Things”

animation on Cells Alive. From the Virtual Microbiology Classroom on ScienceProfOnline.com

http://www.cellsalive.com/howbig.htm

http://www.cellsalive.com/howbig.htm

http://www.scienceprofonline.com/virtual-micro-main.html

http://www.scienceprofonline.com/

http://en.wikipedia.org/wiki/Image:Relative_scale.svg

Two Basic Types of Cells

EukaryoteProkaryote

Images: Prokaryotic cell diagram & Eukaryotic cell diagram, M. RuizFrom the Virtual Microbiology Classroom on ScienceProfOnline.com

http://en.wikipedia.org/wiki/File:Average_prokaryote_cell-_en.svg

http://en.wikipedia.org/wiki/File:Animal_cell_structure_en.svg



Separates the cell from its environment.

Phospholipid molecules oriented so that hydrophilic water-loving heads directed outward and hydrophobic water-hating tails directed inward.

Proteins embedded in two layers of lipids (lipid bilayer).

Membrane is semi-permeable.

Plasma Membrane

From the Virtual Microbiology Classroom on ScienceProfOnline.comDiferencias de las archaeas

http://www.scienceprofonline.org/chemistry/what-are-proteins-amino-acids-peptide-bonds.html



Prokaryotes - Cell Wall Gram-Positive & Gram-Negative

Images: Sources UnknownFrom the Virtual Microbiology Classroom on ScienceProfOnline.com



From the peptidoglycan inwards all bacteria are very similar. Going further out, the bacterial world divides into two major classes (plus a couple of odd types). These are:

Gram Positive Gram Negative

Prokaryotes - Cell Wall

Images: Staph, Gram Stain, SPO Microbiology Images, T. Port; E coli, Y tambeFrom the Virtual Microbiology Classroom on ScienceProfOnline.com

http://en.wikipedia.org/wiki/File:Pseudomonas_aeruginosa_Gram.jpghttp:/en.wikipedia.org/wiki/File:Pseudomonas_aeruginosa_Gram.jpg



Prokaryotes – Plasma Membrane as a Barrier

Passive Diffusion

Is the diffusion of water across a semi-permeable membrane.

Environment surrounding cells may contain amounts of dissolved substances (solutes) that are…

- equal to- less than

- greater than

…those found within the cell.

Images: Osmosis animation; Osmosis with RBCs, M. Ruiz

CELL

Plasma membrane

Liquid environment

outside the cell.

Liquid environment

inside the cell.

From the Virtual Microbiology Classroom on ScienceProfOnline.com

http://people.eku.edu/ritchisong/301notes1.htm

http://en.wikipedia.org/wiki/File:Osmotic_pressure_on_blood_cells_diagram.svg



Plasma Membrane as a Barrier

ACTIVE TRANSPORT

• How most molecules move across the plasma membrane.

• Analogous to a pump moving water uphill.

• Types of active transport are classified by type of energy used to drive molecules across membranes.

• ATP Driven Active TransportEnergy from adenosine triphosphate (ATP) drives substances across the plasma membrane with the aid of carrier molecules.




Prokaryote Genetics

Nucleoid

•Region of cytoplasm where prokaryote’s genome is located.

•Usually a singular, circular chromosome.

Plasmid

•Small extra piece of chromosome/genetic material.

•5 - 100 genes

•Not critical to everyday functions.

•Can provide genetic information to promote:

- Antibiotic resistance

- Virulence factors (molecules produced by pathogen that

specifically influence host's function to allow the pathogen to thrive)

- Promote conjugation (transfer of genetic material between

bacteria through cell- to-cell contact)


http://www.scienceprofonline.org/microbiology/bacterial-genetics-plasmid-dna-conjugation-gene-transfer.html



Prokaryotes Cell Division




Prokaryotes - Endospores

Dormant, tough, non-reproductive structure produced by small number of bacteria.

Resistant to radiation, desiccation, lysozyme, temperature, starvation, and chemical disinfectants.

Endospores are commonly found in soil and water, where they may survive for very long periods of time.

Image: Bacillus subtilis, SPO Science Image Library, Endospore stain from Dr. Ronald E. Hurlbert,

Microbiology 101 lab manualFrom the Virtual Microbiology Classroom on ScienceProfOnline.com

An endospore stained bacterial smear of Bacillus subtilis showing endospores as green

and vegetative cells as red.

http://www.scienceprofonline.com/microbiology/what-is-a-bacterial-endospore.html

http://www.slic2.wsu.edu:82/hurlbert/micro101/pages/101lab6.html



Cell Shapes (Morphology)

Most bacteria are classifies according to shape:

1. bacillus = rod-shaped

2. coccus = spherical

3. Spiral Shaped

a. spirillum = spiral with rigid cell wall, flagella

b. spirochete = spiral with flexible cell wall, axial filament

There are many more shapes beyond these basic ones. A few examples:

– Coccobacilli = elongated coccal form

– Filamentous = bacilli that occur in long threads

– Vibrios = short, slightly curved rods

– Fusiform = bacilli with tapered ends


Acidithiobacillus

Archaea

Leptospirillum

Sulfobacillus



Crecimiento Microbiano

• Refers to increase in the number of microbes (reproduction) rather than an increase in size of the microbe.

• Result of microbial growth is the colony = aggregation of cells arising from single parent cell.

• The time required for growth and reproduction is known as the doubling or generation time.




Doubling Time in Cell Count From Binary Fission

Generation Cell Number Count

0 11 22 43 84 165 3210 1,02420 1,048,576




Bacterial Population Growth Curve

Image: Bacterial growth phases, Michal KomorniczakFrom the Virtual Microbiology Classroom on ScienceProfOnline.com

http://en.wikipedia.org/wiki/File:Bacterial_growth_en.svg



Generation Time Under Optimal Conditions

Organism Generation Time

Bacillus cereus 28 min

Escherichia coli 12.5 min

Staphylococcus aureus (causes many types of infections) 27-30 min

Acidithiobacillus ferrooxidans 10-12 hrs

Archaea (Acidianus, Sulfolobus, Metallosphaera) 10-30 hrs




Microbial Nutrition

• Organisms use a variety of nutrients for:– their energy needs – to build organic molecules & cellular

structures.

• Most common nutrients contain necessary elements:

– Carbon– Oxygen– Nitrogen– Hydrogen

• These 4 elements make up 95% of dry weight of bacterium.

• The other 5% is composed of Calcium, Copper, Iron, Magnesium, Manganese, Phosphorus and Iron.

• Other elements that are needed are ___________ __________.

• These elements are needed in extremely small amounts, can be obtained through water intake.


Factors Influencing Microbial Growth

•Nutrition

•Oxygen

•Temperature

•pH

•Osmotic Pressure


La vida en mundo desde 3.8 Ba

18Los tres dominiones de vida

Microbes & Temperature

Proteins Three-dimensional shape because of the

temperature sensitive hydrogen bonds.

These bonds will usually break at higher temperatures, and protein become unfolded.

Denatured proteins lose function.

Cell Membrane

Also temperature sensitive.

Become brittle if temperature is too low.

If temperature too high, lipids will be more liquid in form.

Outside membrane cannot preserve the integrity of the cell and it will disintegrate.


Categories of Microbes Based on Temperature Range

Ambientes frios

Transporte de equipo a Glaciar de Fremont

Taladro de hielo con equipo termal

Glaciar de Fremont

Meet the Microbe!

Psychrophilic Alga: Chlamydomonas nivalis

Largest Image: Watermelon snow, Will Beback


Ambientes de alto calor

Mt. Soufriere, Montserrat

Calcite Springs, Yellowstone

Obsidian Pool, Yellowstone

Realgar Springs, Yellowstone

Ambientes de bajo pH

Mina Morenci, ArizonaMina Blackbird, Idaho

Mina Parys, Gales Roaring Mountain, Yellowstone

Distribuicion de algunos microorganismos segun su pH(Adaptado de Madigan et

al., Brock Biology of Microorganisms, 2003)

How does the geology influence the microbiology (or is it the other way around?)

El geiser ‘Cinder Pool’

Ambientes radioactivos

QuickTime™ and aTIFF decompressor

are needed to see this picture.

INTEC-666 pool

Dual corrosion cells

Biofilm on AL-6061

Acridine orange-stained AL

Al fondo de los oceanos

JAPEX sampling in the Nankai Trough, Japan

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1_Microbiologia