1. The Microbial World

3. Prokaryotes Vs. Eukaryotes

4. Mircrobes of the Ocean

5. Primary Producers
Are the organisms that produce bio-mass from inorganic compounds (autotrophs).
-Photosynthetic autotrophs
Phytoplankton –
Cyanobacteria
Algae
Diatoms
Dinoflagellates
Plants
-Chemosynthetic autotrophs – release energy from chemical compounds such as H2S & CH4
Archaea – (Hydrothermal vents)
Bacteria – nitrosomonas and nitrobacter
-Heterotrophs – energy from organic matter
by respiration “Decomposers”
Bacteria
Fungi

6. Phytoplankton
photosynthesizing microscopic organisms (autotrophs) that inhabit the upper sunlit layer of almost all oceans and bodies of fresh water
They form the base of the ocean food chain.
phytoplankton are a diverse group, incorporating protists eukaryotes and both bacterial and archaebacteria prokaryotes

7. Aerobic respiration Aerobic metabolism
Oxygen
Aerobic
respiration
Consumed by
CONSUMERS
Zooplankton
Animals
Carbon dioxide
Wastes
Die
Anaerobic
bacteria
DECOMPOSERS
Aerobic bacteria
and fungi
PRIMARY PRODUCERS
Photo-synthesizers
Cyanobacteria
Phytoplankton
Multicellular algae
Plants
Chemo-synthetic
bacteria
Consumed by
Nutrients released
Nitrogen
Sulfur
Phosphorus
Aerobic
metabolism
Fermentation
Stepped Art
Fig. 6-6, p. 131

8. Bacteria General characteristics
simple, prokaryotic organization: no nucleus or membrane-bound organelles, few genes, cell wall
Can live in both aerobic (with O2) and anaerobic (without O2) environments
reproduce asexually by binary fission
many shapes and sizes
bacillus—rod shape
coccus—spherical shape
Spirillum – cork screw shape

9. Bacteria Bacteria usually have one of three different cell shapes
Coccus
(Sphere-shaped)
Ex: Streptococcus
Bacilli
(rod-shaped)
Ex: Lactobacillus
Spirillum
(Spiral-shaped)
Ex: Spirillium

10. Cyanobacteria (blue-green bacteria)
Photosynthetic bacteria which are found in environments high in dissolved oxygen, and produce free oxygen
Usually found in low depths of ocean
Contain chlorophyll a and b
First photosynthetic organisms on earth

11. Cyanobacteria
Form associates called stromatolites—a coral-like mound of microbes that trap sediment and precipitate minerals in shallow tropical seas – 3.2 billion years old

12. Algal Blooms
algal bloom (large concentrations of aquatic microorganisms usually phytoplankton)
Caused by cyanobacteria or dinoflagellates that are often green, but they can also be other colors such as yellow-brown or red
high concentrations
Can produce some of the most powerful toxins known harmful algal blooms (HABs), which are red tides caused by the Protist Dinoflagellates or Diatoms
Mass killings the production of neurotoxins which cause mass mortalities in fish, seabirds, sea turtles, and marine mammals
human illness or death via consumption of seafood contaminated by toxic algae

13. Algal Blooms
algal bloom (large concentrations of aquatic microorganisms usually phytoplankton)
Caused by cyanobacteria or dinoflagellates that are often green, but they can also be other colors such as yellow-brown or red
high concentrations
Can produce some of the most powerful toxins known harmful algal blooms (HABs), which are red tides caused by the Protist Dinoflagellates or Diatoms
Mass killings the production of neurotoxins which cause mass mortalities in fish, seabirds, sea turtles, and marine mammals
human illness or death via consumption of seafood contaminated by toxic algae

14. Red Tides

15. Nitrogen Fixation
Nitrogen fixation: process that converts molecular nitrogen dissolved in seawater to ammonium ion
major process that adds new usable nitrogen to the sea
only some cyanobacteria and a few archaeons with nitrogenase (enzyme) are capable of fixing nitrogen

16. Nitrification
Nitrification: process of bacterial conversion of ammonium (NH4+) to nitrite (NO2-) and nitrate (NO3-) ions
bacterial nitrification converts ammonium into a form of nitrogen usable by other primary producers (autotrophs)
Nitrosomonas and Nitrobacter

17. Marine plants Phytoplankton Algae
NITROGEN FIXATION
NITRIFICATION
Nitrogen-fixing
bacteria,
cyanobacteria
2 N
+Hydrogen (H2)
Ammonia (NH3)
Dissolved
nitrogen (N2)
Animal wastes
recycled by
microorganisms
Ammonium (NH4+)
Bacteria +Oxygen (O2)
Nitrite (NO2–)
Nitrate (NO3–)
Ammonia (NH3)
+Hydrogen (H2)
Marine
plants
Microorganisms
Phytoplankton
Algae
Stepped Art
Fig. 6-11, p. 135

18. Other photosynthetic bacteria
anaerobic green and purple sulfur and non-sulfur bacteria do not produce oxygen
the primary photosynthetic pigments are bacteriochlorophylls
sulfur bacteria are obligate anaerobes (tolerating no oxygen)
non-sulfur bacteria are facultative anaerobes (respiring when in low oxygen or in the dark and photosynthesizing anaerobically when in the presence of light)

19. Heterotrophic bacteria
decomposers that obtain energy and materials from organic matter in their surroundings
return many chemicals to the marine environment through respiration and fermentation
Aerobic Respiration
Organic matter + O2 ---> CO2 + H2O + chemical energy
Anaerobic Respiration
Organic matter + H+ ---> CH4 + chemical energy

20. Symbiotic Bacteria
Many bacteria have evolved symbiotic relationships with a variety of marine organisms
Endosymbiotic theory
Mitochondria and chloroplasts evolved as symbionts within other cells
Chemosynthetic bacteria live within tube worms and clams
Some deep-sea or nocturnal animals host helpful bioluminescent bacteria
photophores
embedded in the ink sacs of squid

21. Symbiotic Bacteria
Anglerfish have light emitting symbiotic bacteria in dorsal appendage

22. Archaea General characteristics small (0.1 to 15 micrometers)
prokaryotic
adapted to extreme environmental conditions: high and low temperatures, high salinities, low pH, and high pressure
formerly considered bacteria
differences from bacteria
cell walls lack special sugar-amino acid compounds in bacterial cell walls
cell membranes contain different
lipids, which help stabilize them
under extreme conditions
Hydrothermal vents

23. Archaea Nutritional Types
archaea includes photosynthesizers, chemosynthesizers and heterotrophs
most are methanogens: anaerobic organisms that metabolize organic matter for energy, producing methane as a waste product
halobacteria (photosynthetic), thrive at high salinities
Hyperthermophiles
organisms that can survive at temperatures exceeding 100o C, such as near deep-sea vents
Potential for biomedical and industrial application