Transcript Mo - Bryn Mawr College

Edward I. Stiefel
1942-2006
professor, Princeton Univ.
senior scientific advisor,
Exxon Corporate Research
(ExxonMobil)
Nucleosynthesis: Stars and Nova Explosions Produce Iron
Iron has the highest binding energy per nucleon.
Iron is a relatively abundant element in the cosmos.
Seawater
Crust
[Mo6+] = 10-7 M
[Fe] = 56g/1 kg
[Fe3+] = 10-17 M
[Mo] = 0.001g/1 kg
[W] = 0.001g/1 kg
___) and Molybdenum (------)
___
Iron (Molybdenum
in the Oceans over Time
(-----) and Iron ( ) in the Oceans Over Ti me
Archean
1850-1250 Ma
Phanerozoic
[Fe] < [Mo]
[Mo] < [Fe]
[Mo] < [Fe]
[Fe] < [Mo]
Concentration
Anbar and Knoll, Science (2002)
Evolution of Life on Earth
Lawler (2001)
Storage and yearly changes (fluxes) of the carbon between the atmosphere, water and the
Earth. Quantities are expressed in billion tonnes of carbon. Redrawn from NASA's Earth
Observatory.
‘Biological Pump’ Leads to Burial of Some Organic Carbon
Chisholm (2002)
ExxonMobile patent for using
methanogens
Methanotrophic Bacteria: Use in Bioremediation
R. L. Brigmon
Westinghouse Savannah River Company
Aiken, SC 29808
More Complete Nitrogen Cycle
Ammonia monooxygenase
O2
Nitrification
NO2-
NH2 OH
Nitrogen Fixation
NO3-
N2
NH3
Denitrification
N2O reductase
N2 O
NO
NO2-
NO2Nitrate Assimilation
Reduced
Nitrite
reductace
Oxidized
= Copper Enzymes
More Complete Nitrogen Cycle
Nitrite
oxidoreductase
O2
Nitrification
NO2-
NH2 OH
Nitrogen Fixation
NO3-
N2
NH3
Denitrification
Nitrogenase
N2 O
NO
Respiratory
Nitrate
Reductase
NO2Assimilatory
Nitrate
Reductase
NO2Nitrate Assimilation
Reduced
Oxidized
= Molybdenum Enzyme
Haber Process for
Ammonia Synthesis
(Nitrogen Fixation)
Human Population Growth
Figure 4. The cyanobacterium Anabaena.
The organism lives as a multicellular filament or chain
of cells.
The predominant photosynthetic (bright yellow-green)
cells conduct photosynthesis, while the obviously
large "empty" cells occasionally seen along a filament
are differentiated cells in which nitrogen fixation, but
not photosynthesis, takes place.
photosynthesis
N2
Inorganic Sulfur Cycle
Molybdate
Inhibition
-
PPi
ATP
A
OO
O
SO4
O
O
P
S
O
O
O-
2ATP sulfurylase
APS
HO
Sulfite
Oxidase
A PS reductase
OH
ATP
APS
phosphorylase
ADP
SO3 2-
PAPS reductase
PAPS
Sulfite reductase
H2 S, HS
Tetrathionate
Reductase
S4O 62-
S2O 32-
-
Polysulfide
reductase
Sn2-
S8
ScienceDaily (Oct. 5, 2007) — Thousands of new
kinds of marine microbes have been discovered
at two deep-sea hydrothermal vents off the
Oregon coast by scientists at the MBL (Marine
Biological Laboratory) and University of
Washington's Joint Institute for the Study of
Atmosphere and Ocean.
Their findings, published in the journal Science,
are the result of the most comprehensive,
comparative study to date of deep-sea microbial
communities that are responsible for cycling
carbon, nitrogen, and sulfur to help keep Earth
habitable.
The researchers discovered that while there may
be as few as 3,000 different kinds of archaea at
these sites, the bacteria exceed 37,000
different kinds.
"Most of these bacteria had never been reported
before, and hundreds were so different from
known microbes that we could only identify them
to the level of phylum," says lead author, Julie
Huber of the MBL.
Opalescent Pool in Yellowstone
National Park, Wyoming USA. In
these types of hot springs, the
orange, yellow and brown colors are
due to pigmented photosynthetic
bacteria which make up the microbial
mats. The mats are literally teeming
with bacteria.
Cross section of a microbial mat
showing the different layers of
pigmented bacteria. (in cm.)
Algen zijn belangrijke producenten van Dimethylsulfide (DMS). DMS is een vluchtig gas dat en grote rol speelt bij het ontstaan van
nevel en wolken. Dit principe geldt voornamelijk in het Zuidelijk halfrond. In het Noordelijk halfrond is er te veel industriële uitstoot
die het omzettingsproces van DMS in nevel beïnvloedt.
Research @: www.rug.nl/boom/onderwerpen/klimaat/ijsalgen
Symbiosis, or the living together of different
organisms, allows some species to live in
otherwise hostile environments, so it can be a
powerful mechanism of evolutionary change.
This is especially true in the deep sea. Survival
in some deep-sea environments requires
capabilities that animals alone don't possess.
So teaming up with a microbial partner is the
secret of survival for many host animals living
in such environments.
Dr Goffredi says: "Measures of significant
population sizes, and the discovery of four
additional host species in only three years,
suggests that the Osedax worms and their
bacterial 'partners' are likely to play substantial
roles in the cycling of nutrients into the
surrounding deep-sea community."
This can be put into context by considering
that the Osedax worms and their symbiotic
bacteria can turn-over a large amount of
organic carbon (one whale carcass may weigh
up to 50 tons), approximately 2000 years faster
than the usual mechanism of carbon
deposition to the deep seafloor.