Making biofuel from algae has just got a little bit easier, as a newly engineered strain produces twice as much oil as its wild parent, according to Californian researchers.
Previous attempts to get this type of algae to make more oil crippled its growth, which isn't an issue with this new strain. Without the growth restrictions, we are now one step closer to producing biodiesel on a large scale, say the researchers.
The idea of using fats and oils produced by phototrophic microalgae — microscopic organisms that can produce lipids when grown using light, water and CO2 — to produce biodiesel that can supplement petroleum-based transport fuels has been actively investigated since the late 1970s.
To date, efforts to engineer microalgae to produce more lipids have been restricted to industrial strains that just don't make enough for commercialisation.
Eric Moellering and the team used several engineering tools - including CRISPR–Cas9 gene editing - to identify ZnCys, which regulates accumulation of lipids in industrial strains of N. gaditana.
The researchers modified ZnCys and found that this doubled lipid productivity — to up to five grams per meter per day — while allowing growth at nearly equivalent rates to the parental, unmodified strains.
Understanding how to increase lipid production of microalgae, while retaining their ability to grow, is an advancement toward a microalgal phototrophic production process for lipids that would remove the need for biodiesel to be reliant on sugars produced by land-grown plants.