Palm oil is responsible for widespread deforestation and biodiversity loss—and yet it has become a ubiquitous essential in our food, cosmetics, and toiletries. Now, researchers might have found a solution to this environmental conundrum, buried in something that’s green, slimy, and abundant in nature: microalgae.
Writing in the Journal of Applied Phycology, they report that they’ve managed to extract oil from microalgae that has a similar makeup to palm and other vegetable oils. If produced at industrial scales, the comparatively low-impact, resource-efficient algae could reduce the need for vegetable oil crops, which require huge tracts of land and plenty of resources to grow.
Their discovery hinges on Chromochloris zofingiensis, a type of free-floating green algae found in lakes, ponds, and streams, which has also become a useful model organism in scientific research. In this instance, the researchers built on a body of work seeking to increase the algae’s ability to synthesize lipids, with applications in biofuels and other industries.
In a series of experiments, they bathed algae in different ‘chemical inducers’—substances believed to aid in the production of specific ingredients in the organisms, including lipids. One of these inducers was pyruvic acid, a naturally-occurring ingredient that’s thought to increase the carbon content available for algae to feed off of—and therefore boost the accumulation of fats and other ingredients.
The growing algae were also exposed to high levels of UV light, to accelerate photosynthesis and increase their production.
After this enriched growth period, the researchers washed and dried the algae, extracting a clear oil from the sludge that remained. When they analyzed these oil samples, they found that the lipid content of those mixed with pyruvic acid was highest—increasing by over 16% to comprise over 66% of the algae’s dry weight.
But most importantly for practical and environmental purposes, the lipid profile of these algae closely resembles that of widely-used commercial vegetable oils such as palm oil, suggesting the microalgae could be a substitute.
There was one notable difference: the algae contained a higher share of polyunsaturated fats than vegetable oils, which usually comprise more of the saturated variety and therefore may be less healthy. That means that algae may not only be a more sustainable alternative to conventionally-farmed vegetable oils; they could be a heart-healthier version, too.
These findings emerge just as we begin to catch on to the environmental impacts of conventionally-grown vegetable oils.
Recently, a separate study called for alternative ways of producing vegetable oils—not just the infamous palm oil, but also soybean, rapeseed and sunflower oils which are ubiquitous: all of these emit vast amounts of greenhouse gas through land conversion and fertilizer use, that study revealed.
The research also points to the fallacy of simply rejecting palm oil as a product—an approach taken by several brands—because that may just create a void in the market to be filled with other vegetable oils. And as those crops expand to take palm oil’s place, there’s nothing to stop them repeating the mistakes of that destructive industry. In fact, the above study revealed that emissions from soybean production for instance, were higher than palm—increasing the complexity of simply exchanging palm oil for another land-based crop.
Alternative ways of farming might bring solutions—or the ideal scenario presented by the current study, where oil production is simply decoupled from the land.
With growing commercial interest in the lipid-producing algae, it’s possible that before too long our foods and cosmetics could contain algae oils: the researchers have already calculated that producing a regular bar of chocolate would require 160 grams of microalgae to replace the traditional vegetable oils. They’re also starting to investigate ways to fine-tune the production process to make it even greener, turning to food waste to produce the essential pyruvic acid, and seeking natural light solutions to replace the energy-intensive UV for photosynthesis, they say.
“Uncovering algae as a potential human food source is an opportunity to lessen the impact the food supply chain has on our planet.”
Chen et. al. “Screening and effect evaluation of chemical inducers for enhancing astaxanthin and lipid production in mixotrophic Chromochloris zofingiensis.” Journal of Applied Phycology. 2022.
