Mars had Oceans!

NASA keeps bringing new insights into the history of our universe.
Mars had oceans 4.5 billion years ago.

History of Ocean pH.

Here is a recent publication on the effects of atmospheric CO2 concentrations on ocean pH values.  Please read this paper and let's discuss the implications of biological activity on pH fluxes, biomass production and perhaps global methane budgets.

Cheers
yuri

Lab Projects and Reports

Here is an email that I sent to all of you last week.
Today in class you will confirm the topic for your project or term paper and commence your literature review.  You should shoot for presenting me with a rough draft of the introduction and background section by spring break.  That isn't a firm deadline, but I can tell you that the earlier you get it to me the more we can work on it together to improve it.

OK, here is the email.


1.  Winogradsky Battery.  This is a lab demonstration put together by Dr. Craig Phelps at Rutger's University.  It targets the cycling of iron in sediments at neutral pH values.  Briefly, iron-bearing sand is placed in a lexan column on top of some source of organic reductant (potato starch).  Ferric iron serves as the electron acceptor at depth within the column.  Oxygen entering the top of the column serves as a chemical oxidant for ferrous iron generated by the enzymatic activity of the iron reducers.  Graphite electrodes are installed along the length of the column and permit electronic interrogation of the system.


2.  Construction of gradient chambers containing iron reducing bacteria and a couple of forms of ferric oxide mineral (goethite, hematite, ferric oxihydroxide).  These chambers allow for visual inspection of mineralogical transformation and microscopic inspection of the organisms in real time.  These chambers can also be instrumented with electrodes to determine whether we can electronically manipulate the formation of biogenic minerals.

3. Vanadium/uranium reduction and precipitation in saturated subsurface materials.  I have always been fascinated by reduction spots.  These are areas is sedimentary rock where iron has been reduced and mobilized, making a glayed spot in an otherwise red iron oxide matrix.  Typically in the center of these reduction spot is a small amount of vanadium and uranium, which are reduced and precipitated by the microbes. This has not been demonstrated in the lab, so it would be fun to give it a try.



For those taking Geomicro 4360/4962,  select a topic related to geomicrobiology and write a mini-review paper about it.  You should be prepared to do an extensive literature search and cover the topic as comprehensively as possible.

Here is a list of topics as suggestions.  You can choose others, if you like.

1. Iron reducing bacteria and their role in mineral transformation.
2. Enzymatic uranium reduction
3. Manganese cycling in Lake Oneida
4. Formation and sublimation of methane hydrates.
5. Arsenic based life forms?
6. Microbial contributions to acid mine drainages.
7.  Microbial life in and around hydrothermal vents.
8. Magnetotactic bacteria
9. Selenium reduction
10. Global nitrogen cycles.

OK. See you at 2:00!

Mariprofondus ferrooxydans video!

Video of M. ferrooxydans forming iron ribbon 200um long, making several that compound to be an iron formation meters thick. I hope the file type works

Iron-Oxidizing Papers

Here are two super neat papers about Iron-Oxidizers, one of them (the first one, from 1998) is about some cool Iron-Oxidizing Nitrate-reducers brought up the other day in class. Enjoy!

Anaerobic Fe-Oxidizing Nitrate-Reducing (Phototrophic...?) Bacteria?!
http://aem.asm.org/content/64/12/4846.full

Iron Oxidizing Anoxygenic Phototrophs?!
http://www.nature.com/nature/journal/v362/n6423/abs/362834a0.html

Video of James Lovelock interview suggested by Tyler

Here is a an interview with James Lovelock about the Earth as a self-regulating system.