> http://www.scientificamerican.com/article/genetically-modified-algae-could-replace-oil-for-plastic/ > The researchers are able to make ethylene from algae by altering a part of the organism’s metabolism called the tricarboxylic acid (TCA) cycle, which is involved in biosynthesis and energy production. In genetically unaltered blue-green algae, the cycle can only take in a relatively small fraction, or 13 percent, of the 2 to 3 percent of fixed CO2. But in Yu’s lab, the algae are able to send three times more carbon to the TCA cycle and emit 10 percent of the fixed carbon dioxide as ethylene—at a rate of 35 milligrams per liter per hour. That might not sound like very much, but it represents a thousandfold increase in productivity since he first began working with the cyanobacteria in 2010. By the end of this year, Yu is aiming to increase that productivity to 50 milligrams.
“This is by no means close to the upper limit,” he said, explaining that the ultimate goal will be to convert 90 percent of fixed carbon to ethylene. “I cannot see why it cannot go higher; I haven’t run into a brick wall yet. I don’t know what would prevent that from happening, but of course it could.” Surprisingly, even though the cyanobacteria are producing more ethylene, the organisms are still growing at the same rate as non-ethylene-producing algae. The results demonstrate that the cyanobacteria’s metabolism was much more flexible than previously thought, according to Yu. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
