Microalgae gaining traction in carbon dioxide removal community
Could microscopic plants help fix the climate?
Microbiologist Dr Eduardo Gorron Gomez thinks so. He collaborates closely with the Australian National Algae Culture Collection, investigating the role of lipid production in microalgae and thraustochytrids at CarbonLock.
Enter the world of thraustochytrids
Dion Frampton with one of several small scale tubular photobioreactors at the Australian National Algae Culture Collection, Hobart.
Eduardo explains that thraustochytrids are unique marine microorganisms. They are commonly found in coastal marine environments among silt, mud and decomposing organic matter rich in carbon.
“Thraustochytrids are really effective producers of carbon-rich molecules, such as lipids, and their strains can be grown quickly,” says Eduardo.
“This can help to understand lipid production routes critical in organisms that fix carbon in the form of lipids.”
Carbon dioxide removal (CDR) technologies are central to reaching net zero. The CDR potential of microalgae is gaining traction in the scientific community. Improved understanding of the unique properties of thraustrochytrids could be critical to uncovering novel ways of accelerating CDR.
“We know that algae can capture vast amounts of carbon as biomass that have many potential ecosystem co-benefits. The challenge for the global algal community is demonstrating that intensive algal systems can be reliably and economically deployed at scale while simultaneously making a meaningful contribution to durable CDR. Using thraustrochytrids to understand the metabolic routes involved would be a novel avenue of research in this field,” says Eduardo.
Algal air capture has exciting potential for CDR, alongside more established technologies like enhanced mineralisation and ocean alkalinity enhancement.
“There’s a subset of us who are specifically looking at how that algal air capture can contribute to our net zero goals, alongside direct air capture or enhanced mineralisation technologies, and bolster Australia’s overall CDR potential.”
From short-lived to long-lived products
Most efforts to date have focused on the use of microalgae to manufacture products that are short-lived (examples include bioplastics, biofuels and biodegradable polymers). These products are useful examples of carbon capture and utilisation, or CCU. However, CCU can only enable CDR if the product (containing CO2 captured from the atmosphere) is durable i.e. long-lived and does not re-release CO2.
Eduardo and his colleagues have found that some microalgae strains are able to produce non-biodegradable carbon polymers known as algaenan. Algaenan could be the basis of, or an additive in, many types of long-lived products and materials, or even stored in geological or oceanic reservoirs to guarantee its permanence. Thraustrochytrids could hold the key to improved understanding and manipulation of the critical algaenan synthesis pathways for carbon dioxide removal technologies.
Contributing to the international algal CDR network
Eduardo Gorron Gomez recently showcased his team’s work in understanding lipid production in Australian thraustochytrids.
Many of microalgae and thraustochytrid strains are endemic to Australia and are hence of great interest to the international algae community.
Eduardo travelled to Europe in December to present on behalf of CarbonLock at AlgaEurope 2024 in Athens, Greece.
AlgaEurope provides a unique opportunity to learn and understand all about algae production and commercialisation, with a focus on the European sector. Over 400 key players from more than 45 countries attended the conference.
At the AlgaEurope conference, Eduardo showcased the progress of his team in understanding lipid production in Australian thraustochytrids using genetic analysis.
“It was fantastic to share our progress in helping to understand the genetic mechanisms behind permanent carbon capture compound synthesis in microalgae,” says Eduardo.
“There were many opportunities to network with international scientists working both with thraustrochytrids and microalgae, including genetically modified algae. They provided me with ideas on how to grow thraustrochytrids in ways that are compatible with circular economy approaches, as well as to understand and troubleshoot genetic modification techniques used in algae.”
Looking ahead for CarbonLock
Eduardo (left) with John Benemann (right), a prominent figure in the microalgae industry with a career spanning 50 years. John is the Co-Founder and CEO of Microbio Engineering.
When paired with genetic technologies like CRISPR, CSIRO’s research could help move microalgae and thraustochytrid cultures out of the laboratory and into the hands of manufacturers. Potential durable products range from construction materials to natural and sustainable fire retardant products.
While Eduardo says the mechanisms of algaenan synthesis are still relatively unknown, genetic analysis of microalgae and thraustrochytrids is helping to close our knowledge gaps.
Eduardo’s team, which is led by Mr Dion Frampton and Dr Kim Lee Chang, is investigating an in vitro system to remove genes that they hypothesise are crucial for algaenan production. They have also made the first steps to implement in vivo genetic modifications in both microalgae and thraustrochytrids at CSIRO.
Over the next 18 months, the team plans to perform and evaluate in vivo genetic modifications that can be crucial for algaenan production, as well as to investigate and model the potential of large scale algaenan production in Australia via both empirical and life cycle analyses.