Future Energy Source? City College of San Francisco Community - - PowerPoint PPT Presentation

Future Energy Source?

City College of San Francisco

• Community College
• No research facilities
• 100,000+ students

Background

• Photosynthesis vs. Cellular Respiration
• The Carbon Cycle in an O2 environment:

– Solar energy and CO2 used to produce glucose. – Consumption and metabolic processing of glucose. – Waste elimination – exhalation of CO2.

• Aerobic use of 02.

Photosynthesis (forward reaction) Cellular Respiration (reverse reaction)

Bacteria

• Various bacteria have been used in fuel

cells to generate electricity from organic wastes.

• Photosynthetic bacteria use sunlight to

manufacture glucose.

• Some contain metabolic pathways that

allow the oxidation or reduction of iron.

Other approaches to biology- based energy solutions

• Cellulosic ethanol
• Lipid synthesis by

photosynthetic diatoms

• Electricity generation from

wastewater

• Microbial fuel cells

Our Approach

• Create a solar powered fuel cell by:

– 1: To utilize phototrophic bacteria, contained in a cathode chamber, to accept electrons, CO2, H+, and sunlight to generate glucose (photosynthate). – 2: Glucose is exported to the anode chamber for metabolism by the chemotropic bacteria. This yields electrons, CO2, H+. – 3: The electrons will (ideally) flow from the anode to the cathode to generate a current. CO2 and H+ are exported back to the cathode in a self sustaining cycle.

Fuel Cell Conceptualization

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle Exit valve to alcohol bottle

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle Exit valve to alcohol bottle Anode- R. rerrireducens eats glucose, adds electrons to wire

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle Exit valve to alcohol bottle Anode- R. rerrireducens eats glucose, adds electrons to wire Cathode- R. palustris

• xidizes Fe2+,

makes glucose

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle Exit valve to alcohol bottle Anode- R. rerrireducens eats glucose, adds electrons to wire Cathode- R. palustris

• xidizes Fe2+,

makes glucose H+- selective Nafion membrane balances charge

Fuel Cell Conceptualization

80% CO2/ 20% N2 tank

Many valves

Media bottle and needle Exit valve to alcohol bottle Anode- R. rerrireducens eats glucose, adds electrons to wire Cathode- R. palustris

• xidizes Fe2+,

makes glucose H+- selective Nafion membrane balances charge Dialysis membrane shares glucose

Our “Work Horses”

Chemotropes which reduce Fe3+ :

– S. Oneidensis – R. ferireducines

• Phototropes which Oxidize Fe2+ :

– R. palustris – hopefully transformed!

• Genetic manipulation:

– P. aeruginosa- source of OprB gene (membrane porin sequence). – pJQ200SK plasmid suicide vector for R. palustris. – E. coli- for plasmid production/ purification.

• Isolation of the OprB gene via PCR.
• Site directed mutagenesis to remove

restriction sequence.

• Ligation of “pieces” into a plasmid vector.

The BioBrick

OprB: code for a glucose uniporter, found in

• P. aeurignosa.

IPTG sensory device: Off- the shelf synthetic lac operon (BBa_J61034) OprB Glucose uniporter (BBa_K226001) B0034 B0010 B0012

Glucose Uniporter Device

Results

• Success in plasmid digestion!!
• PCR Proved extremely difficult.
• Amplification of the “short” end of the
• gene. Trouble capturing the entire gene,

multiple attempts. Many primers ordered.

CCSF Facilities

CCSF was unable to provide a laboratory for our use. One memorable time we were up in the green house… Microbio in a spore filled green house???? Most of the PCR reactions were run within a 0.5 m2 area in a storage room.

Acknowledgements

And most importantly…

The generosity of Mrs. Yvonne Koshland

Daniel Koshland recently turned his attention from the study of receptors and signal transduction to the emerging field of bioenergy, looking into the use of cyanobacteria to produce methane…provides for a genetically modified cyanobacteria expressing at least a first foreign gene, wherein the genetically modified cyanobacteria is capable

• f transporting products of

photosynthesis across the cyanobacteria's membrane.

Yvonne Koshland and Daniel Koshland (1920-2007)

Patent application title: Methods and compositions for production of methane gas (filed Sep. 15, 2005 ) Inventors: Daniel E. Koshland, JR. Agents: UC Berkeley, et.al.

• Abstract: The present invention provides

methods and compositions for sustained methane production from atmospheric CO2 and solar energy from the sun. In general the methods involve culturing cyanobacteria in a first culture vessel and collecting and diverting the photosynthesis products, including glucose or acetic acid, to a second culture vessel including methanogenic bacteria….

Koshland patent Claims:

• 17. A genetically modified cyanobacteria

expressing at least a first foreign gene, wherein the genetically modified cyanobacteria is capable of transporting products of photosynthesis across the cyanobacteria's membrane.

• 20. The genetically modified cyanobacteria of

claim 17, wherein the first foreign gene encodes a glucose transporter.

• Source: http://www.faqs.org/patents/app/20090035832#ixzz0U8k4UOLf