Engineered duckweed could be a more sustainable source of biofuel

this exercise is about biofuel whose commercial future is chancy.  However it grows a lot of biomass fast and here we are manipulating the oil content.  Using it to treat waste water is nice, but how about treating the whole Mississippi to remove nutrient run off and then collect the plant product for cattle feed.

The cattle can then put all the nutrients back into the soil to better support regenerative agriculturde.  this should be way better than silage or hay in the winter.

Close management allows cattle to sort of successfully pasture year round, even with winters.  It can be made much easiuer if a quality feed was in place for the difficult times.

Engineered duckweed could be a more sustainable source of biofuel

By Ben Coxworth

October 17, 2022

A close look at the engineered Lemna japonica duckweed, the oil yield of which is reportedly seven times higher than that of soybeans

Brookhaven National Laboratory

While plants such as corn and soybeans are major sources of biofuel, they're grown on land that could otherwise be used for food crops. With that problem in mind, scientists have genetically engineered oil-producing duckweed that could be grown in wastewater.

The study was conducted by researchers from the US Department of Energy’s Brookhaven National Laboratory and New York's Cold Spring Harbor Laboratory. They started with an existing type of duckweed known as L

In what is described as a push/pull/protect effect, one of those genes pushes (increases) the production of fatty acids, one of them pulls (assembles) those fatty acids into triacylglycerol oils, and another protects them from environmental degradation by coating the oil droplets in plant tissue. As a result, the engineered duckweed accumulates oil at almost 10% of its dry weight biomass, which is reportedly a 100-fold increase over the accumulation rate of the plant's wild counterpart.

Its oil yields are also seven times higher than those of soybeans. Unlike soybeans, however, crops of the duckweed wouldn't take up farmland, as they'd be grown in large vessels or ponds. In fact, the scientists suggest that duckweed crops could be grown in the liquid waste runoff from pig and poultry farms, which the plants would help to clean up by drawing excess nutrients out of the water.

One challenge lay in the fact that ordinarily, the gene that pushes fatty acid production also stunts plant growth. In order to get around that problem, the "push" gene was paired with another gene known as a promoter, the latter of which is activated by adding a specific chemical inducer to the water. "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," said the lead scientist, Brookhaven biochemist John Shanklin.

The researchers are now looking into methods of growing the duckweed and extracting oil from it on a commercial scale.