Edward I. Stiefel 1942-2006

professor, Princeton Univ.

senior scientific advisor, Exxon Corporate Research(ExxonMobil)

Nucleosynthesis: Stars and Nova Explosions Produce Iron

Iron is a relatively abundant element in the cosmos.Iron has the highest binding energy per nucleon.

[Fe3+] = 10-17 M

[Mo6+] = 10-7 M

[Fe] = 56g/1 kg

[Mo] = 0.001g/1 kg

[W] = 0.001g/1 kg

Seawater

Crust

Molybdenum (-----) and Iron (___

) in the Oceans Over Time

Anbar and Knoll, Science (2002)

Concentration

Iron (___) and Molybdenum (------) in the Oceans over Time

Archean 1850-1250 Ma Phanerozoic

[Mo] <[Fe] [Mo] < [Fe] [Mo][Fe] <

[Mo] [Fe] <

Lawler (2001)

Evolution of Life on Earth

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. BrigmonWestinghouse Savannah River CompanyAiken, SC 29808

N2

Nitrogen Fixation

Denitrification

Nitrification

Nitrate Assimilation

O2

OxidizedReduced

NH2OH

NO3-

NO2-

NO2-NON2O

NO2-

NH3

More Complete Nitrogen Cycle

Ammonia monooxygenase

N2O reductase

Nitrite reductace

= Copper Enzymes

= Molybdenum Enzyme

N2

Nitrogen Fixation

Denitrification

Nitrification

Nitrate Assimilation

O2

OxidizedReduced

NH2OH

NO3-

NO2-

NO2-NON2ONitrogenase

NO2-

Nitriteoxidoreductase

AssimilatoryNitrateReductase

RespiratoryNitrateReductaseNH3

More Complete Nitrogen Cycle

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

O

A

HO OH

O

PO

S

O-

O-

O

-O

OSO4

2-

ATP PPi

ATP

ADP

PAPSSO32-

ATP sulfurylase

APSphosphorylase

PAPS reductase

Sulfite reductase

H2S, HS-

S8S4O62- S2O3

2-

APS reductase

Sulfite Oxidase

Tetrathionate Reductase

MolybdateInhibition

Polysulfide reductase

Sn2-

APS

Inorganic Sulfur Cycle

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.