MICRB 265 (10/04/13) BIOENERGETICS: Part III - Metabolic Diversity

3 Pages
Unlock Document

Microbiology (Biological Sciences)
Brian Lanoil

MICRB 265 (October 4, 2013) BIOENERGETICS: Part III – Metabolic Diversity (con’t) CO 2eduction: Methanogenesis  Methanogenesis = “methane” + “making”  CO 2 CH 4  Methanogens (bacteria that carry out methanogenesis) are obligatory anaerobes  They are generally chemolithotrophs o Some can metabolize acetate  Responsible for a lot of the methane gas released into the atmosphere o 2/3 of people have methanogens in their gut o 1/3 of people have acetogens in their gut o It’s one or the other… they do not co-exist Aerobic Chemolithotrophy  Nitrification (ammonia  nitrate and nitrite) o Primary component of wastewater treatment o Nitrate is good fertilizer  Too much = polluted groundwaters  Sulfur Oxidation  Iron oxidation o Con: Leads to corrosion of metal structures o Makes iron insoluble to plants Reverse Electron Flow  CO 2ixation requires a lot of NADH for electrons  Most of these alternative energy sources (having and electron terminal acceptor other than O 2 have a E 0ess than that of NAD+/NADH and therefore, reverse electron flow is required to generate NADH o Reverse electron flow is efficient BUT it does require energy o If you look at the tower of power, only 3 groups are able to produce NADH without reverse electron flow  Chemolithotrophs use inorganic carbon while fermenters use organic carbon Sulfur Oxidation  HS , S2 3, S have E m0re positive than NAD/NADH o You know what this means…. Reverse electron flow is REQUIRED! Iron Oxidation  The acidic environment saves the cell energy because it doesn’t have to pump protons outside of the cell to create a gradient. H is consumed from within the cell to produce this gradient instead o This method also keeps the pH of the cell’s inside near neutral  Reverse electron flow required to make NADH (lower on the tower of power) 2+  Rusticyanin oxidizes Fe o Ferrous
More Less

Related notes for MICRB265

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.