A green plant may be too green, but if a new process holds true, it may help bring in more green.
In pursuing cleaner energy, unicellular microalgae may work out as a possible source in the pursuit of a viable biofuel, said scientists at the University of California, Berkeley.
By genetically modifying the tiny organisms, the researchers can minimize the number of chlorophyll molecules needed to harvest light without compromising the photosynthesis process in the cells. With this modification, instead of making more sugar molecules, the microalgae could produce hydrogen or hydrocarbons.
Researchers discovered the genetic instructions in the algae genome responsible for deploying 600 chlorophyll molecules in the cell’s light-gathering antennae. Algae can get along with as few as 130 molecules, the researchers said. Basically they divert the normal function of photosynthesis from generating biomass to making products such as lipids, hydrocarbons, and hydrogen.
The algae’s chlorophyll antennae help the organisms compete for sunlight absorption and survive in the wild, where there is limited sunlight, said Tasios Melis, a scientist at Berkeley and an author of a paper on the subject. The problem is that may also be detrimental to the engineering-driven effort of using algae to convert sunlight into biofuel, Melis said.
“Cellular optics” describes the effort to maximize the efficiency of the solar-to-product conversion process, Melis said. Besides getting the algae to convert more sunlight to fuel, another issue that needs addressing is how to configure bio-culture tanks in such a way that sunlight can penetrate the outer layer of algae so lower-down layers can participate in the photo-conversion, too.
Microalgae are ideal because of their high rate of photosynthesis; they are perhaps 10 times more efficient in this than sugarcane, corn, and switchgrass, which researchers say are possible biofuel stocks.
What is the timetable for algae to become a viable fuel?
“Progress is substantial to date, but not enough to make the process commercially competitive with fossil fuels,” Melis said. “Further improvement in the performance of photosynthesis under mass culture conditions, and in the yield of biofuels by the microalgae are needed before a cost parity with traditional fuels can be achieved.”
Tags: alternative fuel, green, Microalgae