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Friday, January 20, 2012

Malaria’s ‘cloak of invisibility’ unveiled



WALTER AND ELIZA HALL INSTITUTE OF MEDICAL RESEARCH   

BeauDamonRichardsGallery_-_malaria
The molecule instructs malaria parasites to employ its invisibility clock...and helps its offspring to remember how to 'make' the cloak.
Image: BeauDamonRichardsGallery/iStockphoto
The discovery by researchers from the Walter and Eliza Hall Institute of a molecule that is key to malaria’s ‘invisibility cloak’ will help to better understand how the parasite causes disease and escapes from the defences mounted by the immune system.

The research team, led by Professor Alan Cowman from the institute’s Infection and Immunity division, has identified one of the crucial molecules that instructs the parasite to employ its invisibility cloak to hide from the immune system, and helps its offspring to remember how to ‘make’ the cloak.

In research published in the journal Cell Host & Microbe, Professor Cowman and colleagues reveal details about the first molecule found to control the genetic expression of PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1), a protein that is known to be a major cause of disease during malaria infection.

“The molecule that we discovered, named PfSET10, plays an important role in the genetic control of PfEMP1; an essential parasite protein that is used during specific stages of parasite development for its survival,” Professor Cowman said.

“This is the first protein that has been found at what we call the ‘active’ site, where control of the genes that produce PfEMP1 occurs. Knowing the genes involved in the production of PfEMP1 is key to understanding how this parasite escapes the defenses deployed against it by our immune system,” he said.

PfEMP1 plays two important roles in malaria infection. It enables the parasite to stick to cells on the internal lining of blood vessels, which prevents the infected cells from being eliminated from the body. It is also responsible for helping the parasite to escape destruction by the immune system, by varying the genetic code of the PfEMP1 protein so that at least some of the parasites will evade detection. This variation lends the parasite the ‘cloak of invisibility’ which makes it difficult for the immune system to detect parasite-infected cells, and is part of the reason a vaccine has remained elusive.

Professor Cowman said identification of the PfSET10 molecule was the first step towards unveiling the way in which the parasite uses PfEMP1 as an invisibility cloak to hide itself from the immune system. “As we better understand the systems that control how the PfEMP1 protein is encoded and produced by the parasite, including the molecules that are involved in controlling the process, we will be able to produce targeted treatments that would be more effective in preventing malaria infection in the approximately 3 billion people who are at risk of contracting malaria worldwide,” he said.

Each year more than 250 million people are infected with malaria and approximately 655,000 people, mostly children, die. Professor Cowman has spent more than 30 years studying Plasmodium falciparum, the most lethal of the four Plasmodium species, with the aim of developing new vaccines and treatments for the disease.
Editor's Note: Original news release can be found here.

Protecting houses from bushfires



THE AUSTRALIAN NATIONAL UNIVERSITY   

tuchkovo_-_bushfire
“Clearing vegetation within 40 metres of houses was twice as effective as prescribed burning.” 
Image: tuchkovo/iStockphoto
Clearing vegetation close to houses is the best way to reduce the impacts of severe bushfires, according to a team of scientists from Australia and the USA who examined house loss as a result of Black Saturday.

The research involving 12,000 measurements at 500 houses affected by the Black Saturday fires was only made possible by the sheer size of the devastation of February 7, 2009.

“More than any other major wildfire in Australia, Black Saturday provided an unprecedented opportunity to learn about the effects of land management on house loss,” said senior author Dr Philip Gibbons from The Australian National University.

The research team found that fuel reduction close to houses afforded the greatest protection.

“Clearing trees and shrubs within 40 metres of houses was the most effective form of fuel reduction on Black Saturday,” said Dr Gibbons. “However, there was less risk to houses from vegetation in planted gardens compared with vegetation in remnant native bushland.”

Houses close to public forest were at greater risk, but concerns raised after Black Saturday about national parks were not reflected in the results.

“On Black Saturday, houses were at similar risk whether they were adjacent to national park or state forest,” said Professor David Lindenmayer from ANU, a co-author of the research.

Logging native forests did not reduce the chance of house loss.

“We found no significant relationship between house loss and the amount of logging in the landscape,” said Professor Ross Bradstock from The University of Wollongong who was an expert witness in the Bushfires Royal Commission.

A key issue after Black Saturday was prescribed burning. However, the researchers found that prescribed burning was not the best way to protect houses, despite examining landscapes that had been burnt considerably prior to Black Saturday.

“Clearing vegetation within 40 metres of houses was twice as effective as prescribed burning,” said Dr Geoff Cary from ANU.

All forms of fuel reduction examined in the study, including prescribed burning, were most effective if undertaken closer to houses, but the research team cautions that reducing fuel close to houses is not always an appropriate strategy.

“Intensive fuel reduction close to houses can be expensive, can have significant environmental and aesthetic impacts and can be risky in some circumstances,” said Dr Gibbons. “Many of these issues can be avoided if new housing is not permitted adjacent to forests.”

The researchers conclude that fuel reduction close to houses is only a partial solution to bushfires.

“No amount of fuel reduction will guarantee that a house is safe on extreme weather days like Black Saturday, so it is critical that other measures, such as early evacuation, safer places and architectural solutions are considered by every resident in fire-prone areas in addition to, or instead of, fuel reduction,” said Dr Gibbons.

“These are findings that are probably important internationally,” said Dr Max Moritz from the University of California at Berkeley who was a co-author of the research.

“Housing density in many bushfire-prone regions is increasing, so the next major bushfire will be even more devastating unless we continue to learn from Black Saturday,” added Dr Gibbons.

The research has been published today in the journal PLoS ONE and is available online.
Editor's Note: Original news release can be found here.

Breast cancer spread triggered by a cleaver-wielding protein on cancer cell’s surface



 
by  

Scientists from the University of Helsinki and from UCSF have exposed a cell pathway that breast tumor cells use to destruct local tissue neighborhood. Cancer cells may use this pathway to free themselves from mammary epithelial tissue architecture, to spread to surrounding tissues. The cell pathway, the researchers found, is a biochemical chain of events leading to activation of a protein-cleaving enzyme on the surface of the tumor cells.
Cancer rarely kills unless it evolves the ability to spread beyond the tissue in which it developed, to grow into surrounding healthy tissues. An important roadblock for tumor spread is membranous scaffolding, basement membrane, which lines epithelial cell layers in tissues. Normal epithelial cells and even early-stage tumor cells remain tightly tethered to basement membrane, which segregates healthy and likewise cancerous epithelial cells from surrounding tissues. Breakdown of this barrier allows tumor cells to escape from the tethers of the epithelium, launching a tumor invasion to healthy tissues.
Finnish scientists from the University of Helsinki, together with UCSF researchers, have identified a molecular pathway in breast tumor cells leading to activation of a protein-cleaving enzyme hepsin on the surface of breast tumor cells. Tumor cells use hepsin to chop basement membrane proteins – to break free from ties and matrix binding them to local neighborhood in their native epithelial tissue, the investigation suggests. The study will be published in the 16th January edition of the Proceedings of the National Academy of Sciences (PNAS).

“If we could delay or prevent a tumor from switching from one that grows in place to one that invades, then that would be a major milestone in cancer treatment,” according to study co-author Zena Werb, PhD, a professor of anatomy at UCSF. Werb has for decades studied the ways in which the behavior of tumor cells is influenced by their surroundings, with a focus on breast tumors.
Working with genetically engineered mouse mammary glands and mammary epithelial fragments isolated from these glands (organoids), University of Helsinki scientist and Finnish Academy Research Fellow Juha Klefström, PhD, along with a University of Helsinki graduate student Johanna Partanen designed and led experiments that resulted in the discovery of a biochemical chain of events that is likely to be initiated by many breast tumor cells when they become invasive.
The research collaborators initially studied a tumor suppressor gene (a gene that prevents the growth of tumors) called Liver Kinase B1 (Lkb1). They found that shutdown of this gene disturbs development of parts of the mammary gland, including milk-secreting tissue structures. Especially, basement membrane, which normally surrounds tissue structures of the mammary gland was damaged and degraded.
A culprit for basement membrane damages was pinpointed: Lkb1 shutdown disconnected hepsin from normal regulation and the protein mistakenly started to blanket the surface of mammary epithelial cells, causing degradation of the basement membrane. Researchers found that inactivation of hepsin allowed the basement membrane to recover. These events may take place in many tumors, as the research found that Lkb1 is missing and hepsin is abnormally expressed in 1 out of 4 human breast cancer samples.
“These findings led us to ask an obvious question: does Hepsin mediated degradation of basement membrane make epithelial cells more cancer-prone?” says Johanna Partanen. She knocked out Lkb1 in the mouse mammary gland. Evidently, hepsin expression was abnormal and basement membrane shattered but even after a year, she did not observe any tumors forming in the glands .
Scanning electron microscope image shows 2000x magnification of the basement membrane damaged by inactivation of Lkb1-gene. Basement membrane is a matrix of tightly knit protein fibers, hiding mammary epithelial cells under the surface in the figure. On the right side, the basement membrane is intact and the surface is smooth and even. On the left side, the membrane is degraded and damaged. The arrow shows an epithelial cell protruded above the surface of damaged membrane. It is thought that such basement membrane breakdown allows tumor cells to free themselves from epithelial layers and to spread deep in the neighboring tissues. Credit: ©Johanna Partanen / University of Helsinki
“I was disappointed with the results. However, then I realized that even though broken basement membrane may give more freedom for cells to proliferate, the cells may just lay there, resting, and not start to over-proliferate unless they are pushed to cell division cycle.”
Partanen re-engineered mice so that she combined cell cycle “driver” oncogene Myc with inactivated Lkb1 gene in the mammary glands and she soon noticed very fast growing mammary tumors in the mice. “We think that it is the combination of Myc empowered cell cycle and cell’s ability to destroy basement membrane, which contributed to the vicious tumor formation” says Partanen.
Will these findings help us to fight cancer? – Maybe, says Juha Klefström: “Hepsin is of a type of protein known as a protease and proteases have been successfully targeted in drug development. We found that deactivation of hepsin in the mammary gland organoids prevents formation of a cancerous phenotype. This finding excites us as it leads us to think that inhibition of Hepsin by drug-like molecules could restrain breast cancer progression. However, we do not know yet if we can cure already formed tumors by blocking hepsin activity. We need to first improve our experimental systems to properly address this question.”
According to Zena Werb, “In humans, breast cancers that have diminished amounts of Lkb1 show strong hepsin expression. Since hepsin sits on the cell membrane, it should be accessible to drugs. We believe that hepsin forms a novel target for treatment of a subset of breast cancer patients.”
____________
Courtesy University of Helsinki 

TOP FIVE HATED COMPANIES




Despite their notoriety, these companies are not well liked. According to a 24/7 Wall St. review these companies ranked as the top 5 most hated in America. Get the list of companies here!
MSN Money shares…
Customers, employees, shareholders and taxpayers hate large corporations for many reasons. 24/7 Wall St. reviewed a long list of companies for which there is substantial research data to choose the 10 most hated in America.
Research comes in two sets. One is public research about consumer satisfaction, customer care, pricing of products and services, and brand impressions. Wall St. research takes into account another set of factors, which include current earnings, profit forecasts, product development and quality, and brand valuations.
We examined each company based on several criteria. We considered total return to shareholders in comparison with the broader market and other companies in the same sector during the past year. We reviewed analyst opinions on those companies that are public. We analyzed data from a broad array of sources, including Consumer Reports, JD Power, the MSN/Zogby Poll, ForeSee and the University of Michigan American Customer Satisfaction Index. We also considered negative press based on 24/7 Wall St.’s analysis of media coverage and the Flame Index, which uses a proprietary algorithm to review more than 12,000 websites and ranks companies based on the frequency of negative words. Finally, we considered the views of taxpayers, Congress and the White House where applicable.
The following are 24/7 Wall St.’s 5 most-hated companies for 2011, in no particular order.
1. Facebook
Facebook has more than 800 million users. Any company of this size is sure to have some detractors. Compared with other leading social media sites, however, Facebook has the lowest customer satisfaction score from the American Customer Satisfaction Index. The site has repeatedly irked users by neglecting personal privacy. Notable events include the introduction of facial recognition software, which spurred an investigation by the European Union, and the Facebook timeline. Facebook received significant negative press for forcing new settings on users that change how their personal information is shared with other people. CEO Mark Zuckerberg has only recently said the company will no longer do this. According to the MSN Money-IBOPE Zogby International customer service survey for 2011, 25.9% of Facebook users described the company’s customer service as poor — the lowest rating.
2. American Airlines
American’s parent, AMR, filed for Chapter 11 bankruptcy in November 2011. That virtually wiped out the value of the holdings of every shareholder. American recently was picked as the worst airline for customer service by the annual Middle Seat scorecard, published in the Wall Street Journal. “For the past five years, American has been among the worst three airlines at on-time performance, a key measure of an airline’s operation since it impacts mishandled bags, bumped passengers and even canceled flights and customer complaints,” the survey’s authors said. The report states that the airline was the worst among major carriers last year for baggage handling and canceled flights, nixing 70% more flights than United (UAL +0.11%) and Delta(DAL +2.18%). With a score of 63 in the American Customer Satisfaction Index section on airlines, American falls near the bottom, well below leader Southwest(LUV +0.89%), which has a score of 81.
3. AT&T
AT&T (T +0.26%) recently received the lowest score given by JD Power for wireless customer care performance. It also was given the lowest rating for customer service by ACSI. AT&T has been dogged by problems with its 3G network, which are now largely behind it. AT&T was attacked by both the government and press for what many observers saw as an attempt to set up a monopoly through its buyout of T-Mobile. Consumers feared the combined company would have extraordinary powers to set prices. The wireless carrier also received the lowest satisfaction rating for cellphone standard service providers, according to Consumer Reports. The MSN Money-IBOPE Zogby International customer service survey reports that 26% of customers rate service as poor.
4. Nokia
Nokia (NOK +0.53%) has punished its shareholders as its percentage of the smartphone market has dropped quarter after quarter. Its stock is down 50% in the past year. Nokia likely will lose its lead as the top handset company in the world to Samsung sometime this year. Nokia was tied for lowest overall satisfaction in JD Power’s 2011 Wireless Traditional Mobile Phone Satisfaction Study. It also has received the lowest ACSI score for wireless telephones. According to Interbrand, Nokia’s brand value has dropped 15% from last year. Nokia has tried to salvage its prospects through an agreement with Microsoft (MSFT -0.09%), whose Windows OS will be used in Nokia smartphones. (Microsoft owns MSN Money.) Despite rave reviews for the new Windows Mobile, a partnership with the weakest mobile OS maker only makes Nokia’s fortunes worse.
5. Goldman Sachs
Goldman Sachs’ (GS +6.79%) poor reputation was cemented when the government sued it for fraud in 2010. The company settled with the government for $550 million, but that was viewed as little more than a slap on the wrist because of the bank’s immense wealth. And the fraud accusations have not stopped — they have actually accelerated. Goldman faces a set of suits over mortgage instruments it sold worth a total of $15.8 billion. The Federal Housing Finance Agency in September accused Goldman of misrepresenting the quality of $11.1 billion worth of residential mortgage-backed securities. In the cases in which Goldman has settled claims, the press has not always been favorable. According to The Wall Street Journal, Goldman agreed to forgive 25% of principal balances on 143 mortgage loans to borrowers in New York, or $13 million of a total principal balance of $52 million. The $13 million is less than a senior banker at Goldman might make in a year. Perhaps those homeowners are part of the Occupy Wall Street protests against big banks, for which Goldman is the poster boy.
Get the entire article at MSN Money!
 

THREE BEST CITIES TO WORK IN



Looking for the perfect city, with the perfect job and the perfect life? If so you may want to keep these cities on your radar. Here are 3 cities which are the happiest places to work and 3 which are the unhappiest places to work. Where do you see yourself this time next year?
Forbes highlights…
These three cities are where some of the nation’s unhappiest workers are, according to online career siteCareerBliss.com.
It’s no surprise that most of the unhappiest places have frigid winters and humid summers. Unwelcomed snowstorms and dreaded heat waves can affect your happiness, but so can income, workplace environment, and career opportunities (or lack thereof).
Our list of the happiest and unhappiest cities to work in, compiled by CareerBliss, is based on analysis of more than 43,000 independent employee reviews. Employees all over the country were asked to evaluate 10 factors that affect workplace happiness. Those include one’s relationship with the boss and co-workers, work environment, job resources, compensation, growth opportunities, company culture, company reputation, daily tasks, and control over the work done does on a daily basis. They evaluated each factor on a five-point scale and also indicated how important it was to their overall happiness.
Heading the list of the unhappiest U.S. cities to work is New Haven, Conn., with an index score of 3.46. New Haven workers expressed the most pessimism in the Growth Opportunities and Company Culture categories, which scored 2.89 and 3.23, respectively.
In the No. 2 spot is Dayton, Ohio. Dayton earned an index score of 3.66. Workers there are most dissatisfied with their growth opportunities and compensation, and most satisfied with their colleagues and daily work tasks.
The third unhappiest city to work in is Milwaukee, with an index score of 3.68.
If you’re hoping to smile more at work, think about moving to Oklahoma City, San Jose or Syracuse. Those are three of the happiest places to work.
But the happiest workers of all are in Miami. With an index score of 4.13, Miami employees said they are more than satisfied with the people they work with and their daily tasks.
Worcester, Mass., holds the No. 2 spot, closely followed by Oklahoma City, Okla. Both cities earned a 4.10 index score.
“CareerBliss data found that the greatest influence on workplace happiness was the growth opportunities available within a city,” Golledge says. “It is not a city’s attractions or overall culture that truly affect employee happiness in a region. The overall growth opportunity and company culture lead to happy employees.”
Get more information at Forbes!
 

WHO SHOULD LEAD YOUR BOARD MEETING?



Boards: The Right Person To Lead One

The best chairman or chairwoman is a mentor, sounding board, and listener.

If you’re constructing an advisory board for your business, you need to be clear about its role and judicious in the choice and range of directors. But there’s no decision more important than who leads your meetings.
This can’t be you. Why not? Because to get the best out of your board, the directors or advisors need to feel able to challenge and question you. That’s a lot less likely to happen when you run the meeting. What you want is someone you trust, preferably someone you admire and who has the success of the business as his or her only goal. This is a mentoring role, not a career steppingstone.
The best chairman I’ve ever worked with was excellent at silence. He managed discussions very thoroughly but largely kept himself out of them. He made sure that no one was left out and he ensured that the questions raised by advisors got an answer. This didn’t mean that he kept himself out of the debates. But he listened as hard for what wasn’t being said as he did to what was. He was also not afraid to make an argument that was counter or oblique to the main trend. People quickly came to trust him because he stopped the board from being too conformist. This is a rare and great gift. If everyone is thinking the same way, you aren’t getting the best from the talent you’ve assembled.
Many people imagine that a good board is one in which everyone gets along and there isn’t any conflict. This is true for publicly-traded companies too. In both cases, they’re wrong. Conflict is how thinking happens in groups. No conflict, no thought. What you want in your chairman is someone who isn’t afraid of conflict and knows how to do it well.
Continue reading this article at INC.com after the break!
 

பென்சிலால் வரையப்பட்ட மகாத்மா காந்தியின் அபூர்வ ஓவியங்கள்


Shree Sai Baba Palki at Kurla Aastha - TV9

Thursday, January 19, 2012

Can Touch Screens Hurt You?



Press on something, and it presses back.
DAVID ZAX 
We all know that we are frail creatures, that life is short and precarious and fraught with risk, and that often its greatest pleasures are the very things that lead us all the more swiftly to our inevitable undoing. I wish I could tell you that our gadgets offered an exception to this rule. Instead, a medical doctor has come along to tell us that our touchscreens are hurting us.
If you do anything enough -- running, jumping, sitting still -- it just winds up hurting you. And it turns out that the same is true for using our beloved touchscreens, per Franklin Tessler, M.D., C.M., writing in InfoWorld.
It’s already been well known that touchscreens positioned upright (that is, perpendicular to the floor -- not in portrait mode) are unpleasant to use. “Touch surfaces don’t want to be vertical,” Steve Jobs once said, but it was hardly a novel idea: designers have always said that having to reach out to press on a vertical screen caused an unpleasantness that was soon dubbed “gorilla arm.”
But it turns out that touchscreens in other positions hold dangers -- “hidden dangers,” per Tessler’s title -- as well. Actually, the very fact that tablets and smartphones can be held in any position makes us likely to use them while employing poor posture. (Almost by definition, it’s hard to set up a mobile device in some standard, ergonomically sound way.)
Touchscreen typing, too, puts us in peril. This is generally true of typing, actually: you’ve of course heard of carpal tunnel syndrome, one of several disorders that can result from the unusual contortions or repeated stress that typing evokes. But touchscreens bring with them an extra danger, a relic of their virtuality. Since we don’t receive tactile feedback from touchscreens, we often aren’t quite sure if we’ve pressed a key or not. (Those ersatz clicking key sounds are the best things engineers have come up with so far, but they’re not doing a lot of good, says Dr. Tessler, especially where there’s background noise.) As a result of this uncertainty, many of us are push-typing rather than touch-typing -- a Cornell ergonomics expert says users press virtual keys eight times as hard as the real thing, with all the consequent stresses that entails.
Even in between sentences, when we hold our fingers poised rigidly to descend, we are causing something called “isometric tension,” says Tessler, which stresses muscles and tendons.
Mobile devices also bring along their own variants of the old problem of eyestrain. If you’re covetous of your battery life, you dim your display, as I do, an inevitably find yourself squinting outside. And higher resolution screens bring with them ever tinier fonts, which strain your eyes even if your screen is bright.
How do we get out of this mess? What are some tips to avoid touchscreen related trauma? I’m not a doctor, and you should really read Tessler’s comprehensive post in its entirety (if only to learn of cool verbs like “dorsiflex”), but here are a few highlights of things both you and manufacturers can do to help stem this incipient plague. Hold your touchscreen in whatever angle helps you see it most clearly when reading, but when writing, hold it at a shallow angle of about 30 degrees. When typing, try to know your own strength, and not overdo it; manufacturers, meanwhile, should continue researching “haptic” (tactile) feedback. And if eyestrain is a problem for you, eschew tiny fonts, get some reading glasses, and ask your doctor about eye drops if your office or home is very dry.
You may now go back to your regularly scheduled browsing. Just take care of yourself, while you’re doing it.

Photosynthesis Fuel Company Gets a Large Investment



Joule Unlimited will build a production plant for turning sunlight and CO2 into liquid fuels.

  • BY PHIL MCKENNA

Green tea: Joule Energy's SolarConverter turns carbon dioxide and sunlight into ethanol fuel at a pilot plant in Leander, Texas.
Joule Unlimited




Joule Unlimited, a startup based in Bedford, Massachusetts, has received $70 million to commercialise
3 technology that uses microörganisms to turn sunlight and carbon dioxide into liquid fuel.
The company claims that its genetically engineered bacteria will eventually be able to produce ethanol for as little as $1.23 a gallon or diesel fuel for $1.19 a gallon, less than half the current cost of both fossil fuels and existing biofuels.
The new funding comes from undisclosed investors and will allow the company to expand from an existing pilot plant to its first small-scale production facility, in Hobbs, New Mexico.
Joule Unlimited has designed a device it calls the SolarConverter, in which thin, clear panels circulate brackish water and a nitrogen-based growth medium bubbling with carbon dioxide. Inside the converter, the engineered microörganisms use energy from the sun to convert the water and gas into ethanol or paraffinic hydrocarbons, the primary component of diesel fuel.

Enclosed solar conversion systems are expensive and difficult to manage. But Joule Unlimited's technology could prove practical because its microbes produce fuel continuously and efficiently.
The company, formerly known as Joule Biotechnologies, claimed in 2009 that its organisms could in theory produce as much as 20,000 gallons of ethanol on an acre of land in single year. Company officials now say their target is 25,000 gallons per acre, and that efficiencies they have already demonstrated take them 60 percent of the way to that goal.
The achievement would put Joule's fuel ahead of cellulosic ethanol in terms of productivity. "Even at 60 percent of our ultimate goal, our productivity is still leaps and bounds above cellulosic ethanol," says Dan Robertson, Joule Unlimited's senior vice president of biological sciences. Cellulosic fuels such as grass and wood chips yield only 2,000 to 3,000 gallons of ethanol per acre per year, Robertson says.
The facility in New Mexico will consist of a five-acre "module" made up of multiple 100-meter-long rows of SolarConverters connected to a central processing plant that collects and separates the fuel. The facility, slated to begin producing ethanol this summer, is located near three natural-gas power plants, each of which can provide carbon dioxide. Joule Unlimited has leased a total of 1,200 acres at the site and says it plans to add additional five-acre modules over time.
In a peer-reviewed paper published last year in the journal Photosynthesis Research, Robertson and others showed that their process can achieve an overall efficiency of 7.2 percent in converting sunlight to liquid fuel. The figure is roughly seven times higher than the efficiency rate of systems that use naturally occurring microörganisms. The key to the increased efficiency, Robertson says, is that the engineered bacteria can secrete liquid fuels continuously. Nonengineered microbes produce oils that have to be harvested and refined into fuels, and the organisms have to be ground up to release the oils, so each batch yields only a single harvest.
The microbes that attain 60 percent of the company's stated productivity goal have been secreting ethanol in outdoor SolarConverters at the company's three-acre pilot plant for the past six months. To increase efficiency, Robertson says, the company will further manipulate the organisms' genetic makeup to limit all biological processes that compete with fuel production. For example, Joule has been working for several years to shut down genetic pathways that allow the organisms to keep growing. That should enable them to devote more energy to fuel production.
Robertson says that the company has just begun to optimize production in its diesel-secreting microbes, which currently yield fuel at a rate that is only 10 percent of the company's goal of 15,000 gallons per acre per year.