Taken from the bottom of the marine food chain, microalgae may soon become a top-tier contender to combat global warming, as well as energy and food insecurity, according to a study by researchers associated with the Cornell Algal Biofuel Consortium, published in the journal Oceanography (December 2016).
“We may have stumbled onto the next green revolution,” said Charles H. Greene, professor of earth and atmospheric sciences, and lead author of the new paper, “Marine Microalgae: Climate, Energy and Food Security From the Sea.” The study presents an overview to the concept of large-scale industrial cultivation of marine microalgae, or ICMM for short.
ICMM could reduce fossil fuel use by supplying liquid hydrocarbon biofuels for the aviation and cargo shipping industries. The biomass of microalgae remaining after the lipids have been removed for biofuels can then be made into nutritious animal feeds or perhaps consumed by humans.
To make the biofuel, scientists harvest freshly grown microalgae, remove most of the water, and then extract the lipids for the fuel. The remaining defatted biomass is a protein-rich and highly nutritious byproduct – one that can be added to feeds for domesticated farm animals, like chickens and pigs, or aquacultured animals, like salmon and shrimp.
After consuming the algae-supplemented feeds, chickens produce eggs with three times the omega-3 fatty acids, according to previous Cornell research.
Growing enough algae to meet the current global liquid fuel demand would require an area of about 800,000 square miles, or slightly less than three times the size of Texas. At the same time, 2.4 billion tons of protein co-product would be generated, which is roughly 10 times the amount of soy protein produced globally each year.
Marine microalgae do not compete with terrestrial agriculture for arable land, nor does growing it require freshwater. Many arid, subtropical regions – such as Mexico, North Africa, the Middle East and Australia – would provide suitable locations for producing vast amounts of microalgae.
A commercial microalgae facility of about 2,500 acres would cost about $400 million to $500 million. Greene said: “That may seem like a lot of money, but integrated solutions to the world’s greatest challenges will pay for themselves many times over during the remainder of this century. The costs of inaction are too steep to even contemplate.”
Microalgae’s potential is striking. “I think of algae as providing food security for the world,” said Greene. “It will also provide our liquid fuels needs, not to mention its benefits in terms of land use. We can grow algae for food and fuels in only one-tenth to one one-hundredth the amount of land we currently use to grow food and energy crops.
“We can relieve the pressure to convert rainforests to palm plantations in Indonesia and soy plantations in Brazil,” Greene said. “We got into this looking to produce fuels, and in the process, we found an integrated solution to so many of society’s greatest challenges.”
Cornell University biological engineers have deciphered the cellular strategy to make the biofuel ethanol, using an anaerobic microbe feeding on carbon monoxide – a common industrial waste gas.
“Instead of having the waste go to waste, you make it into something you want,” said Ludmilla Aristilde, assistant professor in biological and environmental engineering. “In order to make the microbes do our work, we had to figure out how they work, their metabolism.”
Aristilde collaborated with her colleague Lars Angenent, professor of biological and environmental engineering, on the project. She explained, “The Angenent group had taken a waste product and turned it into a useful product.”
To make biofuel from inorganic, gaseous industrial rubbish, the researchers learned that the bacterium Clostridium ljungdahlii responds thermodynamically – rather than genetically – in the process of tuning favorable enzymatic reactions.
Synthetic gas – or syngas – fermentation is emerging as a key biotechnological solution, as industrial-sized operations are looking to produce ethanol from their gaseous waste streams, according to Angenent, a fellow at Cornell’s Atkinson Center for a Sustainable Future. The scientists sought to grasp the physiological nature of the process: “These findings are important for the syngas fermentation community to design future strategies to improve production,” Angenent said.
UCLA biochemists have devised a way to convert sugar into a variety of useful chemical compounds without using cells
UCLA biochemists have devised a clever way to make a variety of useful chemical compounds, which could lead to the production of biofuels and new pharmaceuticals.
“The idea of synthetic biology is to redesign cells so they will take sugar and run it through a series of chemical steps to convert it into a biofuel or a commodity chemical or a pharmaceutical,” said James Bowie, a professor of chemistry and biochemistry in the UCLA College, and senior author of the new research. “However, that’s extremely difficult to do. The cell protests. It will take the sugar and do other things with it that you don’t want, like build cell walls, proteins and RNA molecules. The cell fights us the whole way.”
As an alternative, Bowie and his research team have developed a promising approach he calls synthetic biochemistry that bypasses the need for cells.
“We want to do a particular set of chemical transformations — that’s all we want — so we decided to throw away the cells and just build the biochemical steps in a flask,” Bowie said. “We eliminate the annoying cell altogether.”
The biochemists purified more than two dozen enzymes in particular combinations and concentrations, put them in a flask and added glucose. The enzymes and pathways, created in Bowie’s laboratory, are not necessarily found in nature. “When we don’t have to worry about keeping cells happy, it’s easier to rearrange things the way we want,” he said.
Biofuels pioneer Mascoma LLC and the Department of Energy’s BioEnergy Science Center have developed a revolutionary strain of yeast that could help significantly accelerate the development of biofuels from nonfood plant matter.
The approach could provide a pathway to eventual expansion of biofuels production beyond the current output limited to ethanol derived from corn.
C5 FUEL™, engineered by researchers at Mascoma and BESC, features fermentation and ethanol yields that set a new standard for conversion of biomass sugars from pretreated corn stover—the non-edible portion of corn crops such as the stalk—converting up to 97 percent of the plant sugars into fuel.
Researchers announced that while conventional yeast leaves more than one-third of the biomass sugars unused in the form of xylose, Mascoma’s C5 FUEL™ efficiently converts this xylose into ethanol, and it accomplishes this feat in less than 48 hours. The finding was presented today at the 31st International Fuel Ethanol Workshop in Minneapolis.
“The ability to partner the combined expertise at Mascoma and BESC in engineering microbes to release and convert sugars from lignocellulosic biomass has greatly accelerated the translation of basic research outcomes to a commercial product,” BESC Director Paul Gilna said.
Gilna noted that this success and continued efforts through BESC could go a long way toward reducing the cost of ethanol and growing the number of commercial-level ethanol production plants. A key focus of BESC is to use basic research capabilities and expertise to validate the consolidated bioprocessing approach to improve cost competitiveness.
“Driving down the cost to develop, verify and consolidate bioprocessing was at the heart of the BESC effort when we began in 2007, and this achievement allows us to advance to the next challenge,” Gilna said. “This accomplishment represents a clearly impactful example of how our partnering with industry can accelerate the translation of our research capabilities and findings into commercial products.”
Although cellulosic biomass such as corn stover, wheat straw and bagasse (the fibrous remains after sugar is extracted from sugarcane or sorghum) is abundant and cheap, because of recalcitrance — a plant’s resistance to releasing sugars for conversion to alcohol – it is much more difficult to utilize than corn. However, Mascoma’s new strain of yeast, which is one of many strains Mascoma developed as part of BESC over the last two years, proved highly effective at xylose conversion.
While most processing methods simply convert cellulose to sugar, this new approach also converts hemicellulose, which significantly increases overall sugar yield and thereby increases the level of ethanol produced. In fact, the new strain of yeast simultaneously yields 97 percent conversion of xylose and glucose—and does so in a significantly shorter period of time than existing approaches.
Now scientists have a new technique that avoids the expensive enzymes
Producing second-generation biofuel from dead plant tissue is environmentally friendly — but it is also expensive because the process, as used today, needs expensive enzymes, and large companies dominate this market. Now scientists have a new technique that avoids the expensive enzymes. The production of second generation biofuels thus becomes cheaper, probably attracting many more producers and competition, and this may finally bring the price down.
The world’s need for fuel will persist, also when Earth’s deposits of fossil fuels run out. Bioethanol, which is made from the remains of plants after other parts have been used as food or other agricultural products, and therefore termed “second generation,” is seen as a strong potential substitute candidate, and countries like the United States and Brazil are far ahead when it comes to producing bioethanol from plant parts like corn or sugar canes. Corn cubs and sugar canes are in fact plant parts that can also be used directly as food, so there is a great public resistance to accept producing this kind of bioethanol. A big challenge is therefore to become able to produce bioethanol from plant parts, which cannot be used for food.
“The goal is to produce bioethanol from cellulose. Cellulose is very difficult to break down, and therefore cannot directly be used as a food source. Cellulose is found everywhere in nature in rich quantities, for example in the stems of the corn plant. If we can produce bioethanol from the corn stems and keep the corn cubs for food, we have come a long way,” says Per Morgen, professor at the Institute of Physics, Chemistry and Pharmacy, University of Southern Denmark.