
Brookhaven biochemists engineered duckweed, an aquatic plant, to produce large quantities of oil. If scaled up the approach could produce sustainable bio-based fuel without competing for high-value croplands while also potentially cleaning up agricultural wastewater.
Scientists drive oil accumulation in rapidly growing aquatic plants
Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory and collaborators at Cold Spring Harbor Laboratory (CSHL) have engineered duckweed to produce high yields of oil. The team added genes to one of nature’s fastest growing aquatic plants to “push” the synthesis of fatty acids, “pull” those fatty acids into oils, and “protect” the oil from degradation. As the scientists explain in a paper published in Plant Biotechnology Journal, such oil-rich duckweed could be easily harvested to produce biofuels or other bioproducts.
The paper describes how the scientists engineered a strain of duckweed, Lemna japonica, to accumulate oil at close to 10 percent of its dry weight biomass. That’s a dramatic, 100-fold increase over such plants growing in the wild—with yields more than seven times higher than soybeans, today’s largest source of biodiesel.
“Duckweed grows fast,” said Brookhaven Lab biochemist John Shanklin, who led the team. “It has only tiny stems and roots—so most of its biomass is in leaf-like fronds that grow on the surface of ponds worldwide. Our engineering creates high oil content in all that biomass.
“Growing and harvesting this engineered duckweed in batches and extracting its oil could be an efficient pathway to renewable and sustainable oil production,” he said.
Two added benefits: As an aquatic plant, oil-producing duckweed wouldn’t compete with food crops for prime agricultural land. It can even grow on runoff from pig and poultry farms.
“That means this engineered plant could potentially clean up agricultural waste streams as it produces oil,” Shanklin said.
Leveraging two Long Island research institutions
The current project has roots in Brookhaven Lab research on duckweeds from the 1970s, led by William S. Hillman in the Biology Department. Later, other members of the Biology Department worked with the Martienssen group at Cold Spring Harbor to develop a highly efficient method for expressing genes from other species in duckweeds, along with approaches to suppress expression of duckweeds’ own genes, as desired.
As Brookhaven researchers led by Shanklin and Jorg Schwender over the past two decades identified the key biochemical factors that drive oil production and accumulation in plants, one goal was to leverage that knowledge and the genetic tools to try to modify plant oil production. The latest research, reported here, tested this approach by engineering duckweed with the genes that control these oil-production factors to study their combined effects.
“The current project brings together Brookhaven Lab’s expertise in the biochemistry and regulation of plant oil biosynthesis with Cold Spring Harbor’s cutting-edge genomics and genetics capabilities,” Shanklin said.
One of the oil-production genes identified by the Brookhaven researchers pushes the production of the basic building blocks of oil, known as fatty acids. Another pulls, or assembles, those fatty acids into molecules called triacylglycerols (TAG)—combinations of three fatty acids that link up to form the hydrocarbons we call oils. The third gene produces a protein that coats oil droplets in plant tissues, protecting them from degradation.
From preliminary work, the scientists found that increased fatty acid levels triggered by the “push” gene can have detrimental effects on plant growth. To avoid those effects, Brookhaven Lab postdoctoral researcher Yuanxue Liang paired that gene with a promoter that can be turned on by the addition of a tiny amount of a specific chemical inducer.
“Adding this promoter keeps the push gene turned off until we add the inducer, which allows the plants to grow normally before we turn on fatty acid/oil production,” Shanklin said.
Liang then created a series of gene combinations to express the improved push, pull, and protect factors singly, in pairs, and all together. In the paper these are abbreviated as W, D, and O for their biochemical/genetic names, where W=push, D=pull, and O=protect.
The key findings
Overexpression of each gene modification alone did not significantly increase fatty acid levels in Lemna japonica fronds. But plants engineered with all three modifications accumulated up to 16 percent of their dry weight as fatty acids and 8.7 percent as oil when results were averaged across several different transgenic lines. The best plants accumulated up to 10 percent TAG—more than 100 times the level of oil that accumulates in unmodified wild type plants.
Some combinations of two modifications (WD and DO) increased fatty acid content and TAG accumulation dramatically relative to their individual effects. These results are called synergistic, where the combined effect of two genes increased production more than the sum of the two separate modifications.
These results were also revealed in images of lipid droplets in the plants’ fronds, produced using a confocal microscope at the Center for Functional Nanomaterials (CFN), a DOE Office of Science user facility at Brookhaven Lab. When the duckweed fronds were stained with a chemical that binds to oil, the images showed that plants with each two-gene combination (OD, OW, WD) had enhanced accumulation of lipid droplets relative to plants where these genes were expressed singly—and also when compared to control plants with no genetic modification. Plants from the OD and OWD lines both had large oil droplets, but the OWD line had more of them, producing the strongest signals.
“Future work will focus on testing push, pull, and protect factors from a variety of different sources, optimizing the levels of expression of the three oil-inducing genes, and refining the timing of their expression,” Shanklin said. “Beyond that we are working on how to scale up production from laboratory to industrial levels.”
That scale-up work has several main thrusts: 1) designing the types of large-scale culture vessels for growing the modified plants, 2) optimizing large-scale growth conditions, and 3) developing methods to efficiently extract oil at high levels.
Original Article: Engineering Duckweed to Produce Oil for Biofuels, Bioproducts
More from: Brookhaven National Laboratory | Cold Spring Harbor Laboratory
The Latest Updates from Bing News
Go deeper with Bing News on:
Engineered duckweed
- Engineered Floors Releases 2022 Sustainability Report
Dalton, GA, November 8, 2023-Engineered Floors, parent company of J+J Flooring and EF Contract, has released its 2022 Sustainability Report, illustrating its commitment to ever-improving ...
- Lemna/duckweed processor Lemnature AquaFarms files for bankruptcy, asset sale set for Dec 12
Florida-based foodtech firm Lemnature AquaFarms—which produced proteins and fibers from fast-growing aquatic plant lemna (a.k.a. duckweed)—has filed for bankruptcy. An online auction for the assets ...
- PHEV Review: 2024 Volvo V60 T8 eAWD Polestar Engineered
The 2024 Volvo V60 T8 eAWD Polestar Engineered is a vehicle that requires quite a lot of explanation. Breaking apart its ridiculously long name helps: Volvo you know, V60 means the small wagon ...
- Solid Wood vs. Engineered Wood Cost: Use These 7 Factors to Budget for a New Floor
Solid wood and engineered wood are two common options for homeowners who are choosing hardwood flooring materials. Known for its durability and timeless appeal, solid wood is a popular choice for ...
- The Most Durable Kind Of Engineered Hardwood Flooring You Can Find
When it comes to flooring options, engineered hardwood is a popular choice among homeowners seeking the perfect blend of aesthetics and durability. Unlike traditional hardwood, engineered hardwood is ...
Go deeper with Bing News on:
Plant oil
- Oil firms are out in force at the climate talks. Here's how to decode their language
The oil industry has a huge voice in this year's climate talks. But what are oil companies actually saying? And why does it matter? We break down their pledges and statements into plain English.
- Which Cooking Oils Are Best for Your Health?
Medically reviewed by Karina Tolentino, RD Fats play an essential role in your health. Incorporating healthy fats into meals and snacks can improve nutrient absorption, promote heart health, and help ...
- Watch Live: Cop28 holds event on phasedown of coal power plants
Watch live as Cop28 holds an event on the phasing out of coal power plants in Dubai, UAE, on 5 December 2023. Several nations have already committed to phasing out coal plants, which are known to ...
- Gardener shares genius way to get rid of plant-destroying aphids without using toxic chemicals: ‘[This] totally worked’
And while many insects are helpful, or at least neutral, some — like aphids — can be quite destructive. Luckily, there’s no need to resort to pesticides and chemicals to get rid of aphids, as one avid ...
- The Difference Between Marinating Regular Meat Vs Plant-Based
These days, plant-based meat is similar in both texture and flavor to animal meat, but there's one handy perk of plant-based when it comes to marinades.