Wednesday, May 26, 2010

Photosynthesis, CO2, Biomass from Plants & Algae, Biohydrogen

The changing energy need dynamics is going to affect not only the way energy is produced but also how its going to be used. The winning entry for the city of the future competition of History channel predicts a future for San Francisco that has hydrogen fueled hover car networks. The city will have specific structures to collect, store and distribute water and power from various sources. Harvesting the solar energy would be a very effective contributor. Currently energy is produced by processing the biomass into ethanol and biodiesel. However, energy is lost in producing all the other complex compounds that form the part of the complex biomass. Photosynthetic organisms that produce biofuels directly will be more energy efficient than processing the biomass thats produced by plants. This concept of producing a fermentation product called photanol with the input of carbon dioxide, water and solar energy into a synthetically designed organism.

Being able to produce hydrogen for use as a fuel by splitting water using solar energy is a long term goal to overcome the energy crisis. Various options are being explored to perform the task of splitting. However, using cyano bacteria for photo biological production of hydrogen has been found to be a very promising option. Many micro-organisms can produce hydrogen using enzymes called hydrogenases. This hydrogen production will produce the Biohydrogen which can be used a fuel for various purposes due to its portability.

Two different approaches are being pursued to produce biohydrogen. The first approach is the nitrogenase based approach and it involves knocking out the uptake hydrogenase. The second approach is to introduce a foreign hydrogenase. Both the approaches are being tried out by various companies. Different growth conditions and mechanisms are being observed to get the optimal system.

Interesting developments in using LED technologies as an additional, low-energy artificial supply of light with optimal properties for photosynthesis is being explored. Growing understanding of genetic engineering, regulation of transcription and translation will improve the design of the organism used to produce the fuel. Other areas such as mass culturing of the microorganism can also lead to significant cost reduction and stability.

Due to the complex nature of the biological systems, various problems such as auto inhibition of growth in the model organism while producing the new compound. The resistance mechanisms to such inhibition has to be studied and expressed in the organism to get a higher yield.

No comments: