Navigation Links
Purple is the new green
Date:5/3/2010

CORAL GABLES, FL (May 3, 2010)Purple bacteria were among the first life forms on Earth. They are single celled microscopic organisms that play a vital role in sustaining the tree of life. This tiny organism lives in aquatic environments like the bottom of lakes and the colorful corals under the sea, using sunlight as their source of energy. Its natural design seems the best structural solution for harvesting solar energy. Neil Johnson, a physicist and head of the inter-disciplinary research group in complexity in the College of Arts and Sciences at the University of Miami, thinks its cellular arrangement could be adapted for use in solar panels and other energy conversion devices to offer a more efficient way to garner energy from the sun.

"These bacteria have been around for billions of years, you would think they are really simple organisms and that everything is understood about them. However, purple bacteria were recently found to adopt different cell designs depending on light intensity," says Johnson. "Our study develops a mathematical model to describe the designs it adopts and why, which could help direct design of future photoelectric devices."

Johnson and his collaborators from the Universidad de los Andes in Colombia share their findings in a study entitled "Light-harvesting in bacteria exploits a critical interplay between transport and trapping dynamics," published in the current edition of Physical Review Letters.

Solar energy arrives at the cell in "drops" of light called photons, which are captured by the light-gathering mechanism of bacteria present within a special structure called the photosynthetic membrane. Inside this membrane, light energy is converted into chemical energy to power all the functions of the cell. The photosynthetic apparatus has two light harvesting complexes. The first captures the photons and funnels them to the second, called the reaction center (RC), where the solar energy is converted to chemical energy. When the light reaches the RCs, they close for the time it takes the energy to be converted.

According to the study, purple bacteria adapt to different light intensities by changing the arrangement of the light harvesting mechanism, but not in the way one would think by intuition.

"One might assume that the more light the cell receives, the more open reaction centers it has," says Johnson. "However, that is not always the case, because with each new generation, purple bacteria create a design that balances the need to maximize the number of photons trapped and converted to chemical energy, and the need to protect the cell from an oversupply of energy that could damage it."

To explain this phenomenon, Johnson uses an analogy comparing it to what happens in a typical supermarket, where the shoppers represent the photons, and the cashiers represent the reaction centers.

"Imagine a really busy day at the supermarket, if the reaction center is busy it's like the cashier is busy, somebody is doing the bagging," Johnson says. "The shopper wonders around to find an open checkout and some of the shoppers may get fed up and leaveThe bacteria are like a very responsible supermarket," he says. "They would rather lose some shoppers than have congestion on the way out, but it is still getting enough profit for it to survive."

The study develops the first analytical model that explains this observation and predicts the "critical light intensity," below which the cell enhances the creation of RCs. That is the point of highest efficiency for the cell, because it contains the greatest number and best location of opened RCs, and the least amount of energy loss.

Because these bacteria grow and repair themselves, the researchers hope this discovery can contribute to the work of scientists attempting to coat electronic devices with especially adapted photosynthetic bacteria, whose energy output could become part of the conventional electrical circuit, and guide the development of solar panels that can adapt to different light intensities.

Currently, the researchers are using their mathematical model and the help of supercomputers, to try to find a photosynthetic design even better than the one they found in purple bacteria, although outsmarting nature is proving to be a difficult task.


'/>"/>

Contact: Marie Guma-Diaz
m.gumadiaz@umiami.edu
305-284-1601
University of Miami
Source:Eurekalert  

Related biology news :

1. Purple extremist thrives under inhospitable conditions
2. Fried purple tomatoes
3. Purple tomatoes: The richness of antioxidants against tumors
4. Purple sweet potato means increased amount of anti-cancer components
5. Purple Pokeberries hold secret to affordable solar power worldwide
6. Green tea boosts production of detox enzymes, rendering cancerous chemicals harmless
7. New study shows greenback cutthroat trout involved in recovery effort misidentified
8. American Chemical Society calls green chemistry bill a smart step
9. Salmon garnish points the way to green electronics
10. Using green chemistry to deliver cutting-edge drugs
11. Green skies: Engineers work may reduce jet travels role in global warming
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Purple is the new green
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/15/2016)...  A new partnership announced today will help ... in a fraction of the time it takes ... life insurance policies to consumers without requiring inconvenient ... Diagnostics, rapid testing (A1C, Cotinine and HIV) and ... weight, pulse, BMI, and activity data) available at ...
(Date:3/31/2016)... 2016   LegacyXChange, ... "Company") LegacyXChange is excited to release its ... to be launched online site for trading 100% guaranteed ... will also provide potential shareholders a sense of the ... an industry that is notorious for fraud. The video ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... 2016 , ... Supplyframe, the Industry Network for electronics hardware ... . Located in Pasadena, Calif., the Design Lab’s mission is to bring together ... built and brought to market. , The Design Lab is Supplyframe’s physical representation ...
(Date:6/23/2016)... 23, 2016  Blueprint Bio, a company dedicated to ... medical community, has closed its Series A funding round, ... "We have received a commitment from Forentis ... need to meet our current goals," stated Matthew ... runway to complete validation on the current projects in ...
(Date:6/23/2016)... WI (PRWEB) , ... June 23, 2016 , ... ... focused on quality, regulatory and technical consulting, provides a free webinar ... presented on July 13, 2016 at 12pm CT at no charge. , Incomplete ...
(Date:6/22/2016)... SAN DIEGO , June 22, 2016 /PRNewswire/ ... partnership that will allow them to produce up ... (HiPSC) from one lot within one week. These ... their time laboriously preparing cells and spend more ... made possible through a proprietary, high-volume manufacturing process ...
Breaking Biology Technology: