the microbial world. prokaryotes vs. eukaryotes
TRANSCRIPT
Primary ProducersAre the organisms that produce bio-mass from inorganic compounds (autotrophs). -Photosynthetic autotrophs
Phytoplankton – CyanobacteriaAlgaeDiatoms 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
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
Carbon dioxide
Oxygen
Aerobicrespiration
Aerobicrespiration
PRIMARY PRODUCERS
Photo-synthesizers
CyanobacteriaPhytoplanktonMulticellular algaePlants
Chemo-syntheticbacteria
Consumed byConsumed by
CONSUMERSZooplanktonAnimals
Consumed by
Nutrients released
NitrogenSulfurPhosphorus
Aerobicmetabolism Fermentation
WastesDie
Die
Anaerobicbacteria
DECOMPOSERS
Aerobic bacteriaand fungi
Stepped Art
Fig. 6-6, p. 131
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
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
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
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
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
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
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
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
Nitrogen-fixingbacteria,cyanobacteria
2 N
+Hydrogen (H2)
Ammonia (NH3)
Dissolvednitrogen (N2)
NITROGEN FIXATION
Marineplants
Microorganisms
PhytoplanktonAlgae
NITRIFICATION
Animal wastesrecycled bymicroorganisms
Ammonium (NH4+)
Bacteria +Oxygen (O2)
Nitrite (NO2–)
Nitrate (NO3–)
Ammonia (NH3)
+Hydrogen (H2)
Bacteria +Oxygen (O2)
Stepped Art
Fig. 6-11, p. 135
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)
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
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
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
• 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
Archaea