Do NowClassify the following organisms as as

chemoautotrophs, chemoheterotrophs, photoautotrophs, or photoheterotrophs:

1. Clostridium bacteria break down cellulose for carbon and energy

2. Desulfovibrio breaks down organic acids for energy and carbon.

3. Chlorobium does photosynthesis for energy and carbon, but uses H2S instad of H2O

4. Chromatin does photosynthesis for energy and carbon without producing oxygen.

Observations

• Make your week 2 observations of your Winogradsky columns. Be sure to measure!!!

• Don’t lose your records – we still have 4 weeks to go.

• You have 10 minutes maximum.

Introduction to Bacteria

• There are a RIDICULOUS number of different types of bacteria

They Do Anything

• Trying to describe the diversity of bacteria is like trying to describe the diversity of eukaryotes: you and an Euglena live very different lives!

One Way is with Oxygen Use – Anaerobic or Aerobic?

• Anaerobic organisms do not use oxygen.

• Aerobic organisms require oxygen

• Facultative anaerobes will use oxygen if it is available

• Microaerophilic organisms need a little oxygen

• OXYGEN IS TOXIC!!!

Bacteria = Diversity

• Bacteria live just about everywhere.

• Some are chemotrophs, others are autotrophs, and there’s heterotrophs and phototrophs…

• So where do we begin???

Anaerobes

• Anerobic organisms are good for lots of things:

• Beer, wine, saurkraut, yogurt, cheese, vinegar, olives, bread…

Anaerobic Products

Bad Anaerobes: Gas gangrene is an example of a disease caused by an

anaerobic bacterial infection.

• WARNING !!! The next slide is really graphic.

• It shows gas gangrene.

• View at your own discretion.

Last chance

• Don’t say I didn’t warn you.

• Twice.

Gas Gangrene: Clostridium perfringiens

• This leg will have to be amputated

Happy Anerobes: In our columns

• We will now watch part of an animated description of some of the bacteria in a Winogradsky column.

• For now, we’ll just be talking about the anerobic bacteria at the bottom of the columns.

Clostridium:Anaerobic chemoheterotroph

• Strict anaerobe – dies in contact with oxygen• Breaks down cellulose and then glucose for

carbon and energy.• Can cause gangrene from untreated deep

puncture wounds• Can cause food poisioning in canned foods

(expanded can)

Desulfovibrio: Anaerobic

chemoheterotroph

• Uses fermentation waste products and sulfate to get carbon and energy

• Notice: Aerobic organisms produce H2O during respiration. Anaerobes produce H2S

Oxygen: Sulfur lite

Photosynthesis – New Twists

OXYGENIC PHOTOSYNTHESIS (plants)

• H2O + CO2 CH2O + O2• e- donor + inorganic CO2 carbohydrates + e- acceptor

ANOXYGENIC PHOTOSYNTHESIS (bacteria)

• H2S + CO2 CH2O + S2• e- donor + inorganic CO2 carbohydrates + e- acceptor

Anaerobic Photoautotrophs that use H2S during photosynthesis

• The green and purple sulfur bacteria are seperated by their tolerance of hydrogen sulfide

Not Chlorophyll

Anaerobic Photoautotrophs that use organic molecules instead of H2S

• Still anaerobic

• Use waste of other organisms for electrons

The Bottom Line

• Define: aerobic, anaerobic, facultative anaerobe, microaerophilic.

• Classify bacteria based on their oxygen requirements.

• Describe the chemical formula for anoxygenic photosynthesis as done by the green and purple sulfur bacteria.