Prokaryotic Diversity L10 P1

Morphological Diversity

The diversity is based upon the visual appearance

Metabolic Diversity

Based upon how the microbes obtain energy

Ecological Diversity

Based upon what the cells are doing in the context of their environment and the microbes they interact with, often includes metabolic diversity.

What role they’re playing in the ecosystem

What are Chemotrophs and what are the two types

1. They obtain their ENERGY by oxidizing electron donors around them. (Oxidizing is removing electrons from atoms.)

2. Chemoorganotrophy

3. Chemolithotrophy

What is Chemoorganotrophy

They obtain their ENERGY by oxidizing ORGANIC compounds

What is Chemolithotrophy

They obtain their ENERGY by oxidizing INOORGANIC compounds

What are Phototrophs and what are the two types

1. They capture photons (light energy) to acquire energy

2. Photoheterotrophy

3. Photoautotrophy

What is Photoheterotrophy

They get their ENERGY from sunlight

They get their CARBONS from organic compounds

What is Photoautotrophy

They get their ENERGY from sunlight

They get their CARBONS from inoorganic compounds (CO2)

What is the diversity of phototrophic bacteria

1. How they use light energy to break down CO2 or organic compounds into sugar molecules and organic molecules

What is anoxygenic photosynthesis

1. This evolved first in the world

2. Oxygen is NOT produced as a product in photosynthesis

What is oxygenic photosynthesis

1. Oxygen is produces as a waste product due to the oxidation of H2O.

What is lit anoxic environments

1. They are environments with no oxygen.

2. Anoxygenic Phototrophs live here

3. Ex. Meromictic lakes, Hot spring mats

What is lit oxic environments

1. Environments with lots of oxygens

2. Cyanobacteria is here

3. Oxygen phototrophs are here

4. Thought to have made all the oxygen on the early earth

5. Many have HETEROCYTES used for nitrogen fixation

What are sulfate reducing bacteria

1. They reduce SO4 to H2S for energy

2. They are generally obligate anaerobes

3. they use H2 or ORGANIC compounds as electron donors

What are sulfur oxidizers

1. They get their energy from oxidizing H2S to S

2. Most are OBLIGATE aerobes and some can reduce NO3

3. some are obligate CHEMOLITHOTROPHS

Diversity of nitrogen fixers: What are diazotrophs

1. They are microorganisms that fix N2 gas into usable ammonia.

2. Nitrogen fixation requires ATP and nitrogenase.

3. Nitrogenase wont work if O2 is present

4. Nitrogen fixation is spread among bacteria and a few Archaea

What are nitrifiers

1. They grow chemolithotrophically

2. They oxidize Ammonia (NH3) to Nitrate (NO3) for energy during nitrification

3. They are OBLIGATE AEROBES

4. Nitrification uses TWO sets of reactions. Most can only catalyze one set of reactions

What are Denitrifiers

1. They grow by ANAEROBIC RESPIRATION

2. They use inorganic nitrogen (NO3, NO2) to gaseous NO, N2O, and N2 for energy.

3. Typically facultative aerobes and chemoorganotrophs

What are Microbial predators

They are bacteria that generally consumes other species of bacteria’s.

What are Epibiotic predators

1. They attach to the preys cell wall surface and acquire nutrients from their cytoplasm or periplasm.

What are Cyctoplasmic predators

1. They invade the host cell and replicate in the cytoplasm consuming the cell from within

What are Periplasmic predators

1. They invade the call and enter the periplasm and replicate within.

2. Ex. Bdellovibrio

What are Social predators.

1. They swarm and collectively feed upon lysed prey.

2. Ex. Lysobacter and Myxococcus

Phylogenic Diversity

This diversity is based upon the evolutionary relationship between microbes

What does phyolgenetic diversity look at

1. It looks at the 16s RNA genes

2. 90% of bacteria fall into four PHYLA’s

3. Proteobacteria, Bacterioidetes, Actinobacteria, Firmicutes

Characteristics about Proteobacteria(Phyla)

1. All GRAM NEGATIVE bacteria

2. There are 6 classes based up 16S RNA

3. Every known type of metabolic/functional diversity is represented by species within this phyla

4. Abundant everywhere

Alpha Proteobacteria

1. Many are obligate or facultative intracellular bacteria

2. Some are oligotrophs (they thrive in low nutrients environments)

Beta Proteobacteria

1. diverse group

2. Wide range of metabolic strategies found in many environments

Gamma proteobacteria

1. Diverse group which includes a number of human pathogens

Delta Proteobacteria

1. Diverse group includes sulfate reducing bacteria

2. Has myxobacteria which can form fruiting bodies

Epsilon Proteobacteria

1. Microaerophilic bacteria (require low oxygen environments to survive)

2. Includes some important human pathogens

Description of Firmicutes (Phyla)

1. GRAM POSITIVE bacteria

2. Some species can produce ENDOSPORES

3. generally has low GC content

Description of Actinobacteria (Phyla)

1. GRAM POSITIVE bacteria

2. most harmless but not Mycobacterium tuberculosis

3. Primarily aerobic filamentous soil bacteria

4. Generally has a high GC content

Description of Bacteroidetes (Phyla)

1. GRAM NEGATIVE bacteria

2. Non sporulating rods

3. GLIDING motility is common

4. Many bacteria in this phylum is associated with the HUMAN gut

Description of Cyanobacteria

1. All OXYGENIC Phototrophs

2. Many are capable of gliding motility

3. Diazotrophs

4. contains gas vesicles

Description of Chlorobi

1. Anaerobic anoxygenic phototroph: GREEN SULFUR BACTERIA

2. Typically non-motile

3. Short to long rods

4. Oxidizes H2S to SO4 for autotrophy

5. Contains bacteriochlorophyll in chromosomes so its green in colour.

Description of Chloroflexi

1. Anoxygenic phototroph: GREEN NON-SULFUR BACTERIA

2. Aerobic and anaerobic chemoorganotrophs

3. All capable of gliding motility

4. Not all green in colour

Explain the relationship between diversity

1. Organisms closely related on the evolutionary family tree doesn’t mean they look, act, or function the same way

2. Closely related species can have different physiological properties (functional capabilities)

3. Distantly related species can have similar physiological properties

What explains the relationship between diversity

1. Gene loss (Loss of genes in some lineages)

2. Convergent evolution (independently evolution so separate organisms developed the exact same traits without having a common ancestor)

3. Horizontal gene transfer (Genetic exchange)

What is Metagenomics

It detects as many genes are possible and produces a picture of the gene pool in an environment.

This allows for a link to function and for the comparison of environments.

a powerful laboratory technique where scientists scoop up a sample of soil, water, or mud and sequence all the DNA inside it at the exact same time.