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B a c t e r i a a s L i v i n g

b a tt e r i e s ? ? ?

Ever increasing Need for ENERGY

What are the

alternatives to fossil fuels

?

Newer solutions...

Fuel cells

Advantages of Fuel Cells

vs.

Internal Combustion Engines

Unlimited supply of fuel

No reliance on foreign oil

Little or no pollutants

No moving parts

No noise

Bacterium That Eats Radioactive Garbage And Generates Electricity

•Geobacter sulfurreducens possesses extraordinary capabilities to transport electrons and "reduce" metal ions as part of its energy-generating metabolism.

•Bacterium with the potential to bioremediate radioactive metals and generate electricity was found.

Forget Horsepower, Think Cow-Power

• Microbes in about a half a liter of rumen fluid - fermented, liquefied feed extracted from the cow's stomach - produced about 600 milli volts of electricity.

• Some of the micro-organisms found in cow waste could provide a reliable source of electricity.

Sediments at the bottom of Boston Harbor

Iron Breathers

Desulfuromonas acetoxidans

What are they???

• Bioreactor: type of battery

• Produces electrochemical redox energy

• Renewable and sustainable energy

• Converts chemical energy, available in a bio-convertible substrate, directly into electricity

Goal : Produce electricity while simultaneously

degrading organic matter.

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Microbial fuel cells

• Organic matter is oxidized by bacteria creating an electric potential.

• Electrons produced are transferred to anode and flow to cathode.

Microbial fuel cells may use wastewater as a fuel, or more generally a dilute solution of a variety of organic materials in water.

Electron Transport chain

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Anode Chamber– Stores fuel

-->

Cathode Chamber

– Exposed to air<--

M e m b r a n e - Allows for H + passage^

Catalyst Often Platinum

V V

Usually graphite, carbon cloth/paper

Anode

20202020

Biocatalysts

Bacteria-metal reducing bacteria

Heterotrophic, auto heterotrophic, mixed-culture

Cathode

Carbon Rod and Carbon Fiber Electrodes

Proton exchange membrane

• Commonly Nafion or Ultrex ; salt bridges also used

• Barrier between anodic and cathodic chambers

• Must be permeable to charged species, reduce oxygen transfer to anodic chamber

C6

H1

2O

6

6H2O

6 CO

2

24 H+

24e

-

As an example, Glucose is used as organic substrate

Anode

24 H+ 24e-

Cathode

Click icon to add picture

Electro active Bacteria

Other species include :

• Shewanella putrefaciens • Aeromonas hydrophila

• Pseudomonas species

Some bacteria, which have pili on their external membrane, are able to transfer their electron production via these pili.

Examples of microbial-based fuel cells

Microbe

Substrate

Mediator

Anode Voltage

E coli Glucose MethyleneBlue

Pt- C-cloth 625mV

Bacillussubtilis

Glucose Thionine VitreousCarbon

640mV

E coli Acetate Neutral red Graphitefelt

250mV

Pseudomonasmethanica

Methane 1-Naphthol-2-Sulfonate indo-2,6 dichlorophenol

Pt-black 550mV

Proteusvulgaris

Sucrose Thionine Carbon rod 350mV

Robotics -Studies in “Gastro bots: Autonomous robots powered by MFC’s could consume food (biomass) as seemingly limitless source of energy

Portable units- power generationMicro pumps-insulin, pain meds, arthritis

Current for-nerve stimulation, hearing aidsHeart pacemaker (cells in series)Renewable and sustainable source of electricity.

Biosensors Aerospace applications aim to generate power and remediate pollutants from human waste aboard exploratory missions with large crews

Powering electronic monitoring devices in remote locations, such as

the bottom of the ocean

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Advanced Water Management Centre ------

constructed a pilot scale microbial fuel cell. The pilot scale plant was built on the site of the Foster's brewery in Yatala, Queensland (Australia).

          Urine: Waste Product or Future Power Source? -----

Researchers in the UK are looking into the use of urine as the ‘fuel’ for microbial fuel cells (MFCs), which use bacterial cultures to break down ‘food’ to create power.

IntAct Labs LLC in Cambridge -----

recycling waste products during space missions.

Harvard University ---------

provide power for lighting and other systems in developing nations

Derek Lovley’s Geobactor Project at UMass Amherst ------

looking to create organic batteries that could one day power computers or even vehicles.

Hy-SyEnce Inc.  (Fall River) ------

wastewater of food-processing plants

From waste to power in one step!

Towards a promising future…The mechanisms of electron transfer between the microorganisms and the electrode should be elucidated in order to design better electrodes or genetically engineer better microbes for higher rates of electricity production.

Research continues to seek robust microbial biocatalysts, improve design, better electrode materials, more effective mediators

Not marketable yet, but research continues to improve prospects

Thank you!!!

Questions???