Western Researchers Pioneer New Method for Algae Biofuel Production

A team of researchers at Western University has developed a groundbreaking method for engineering diatoms, a type of single-celled algae, to produce more sustainable biofuels and nutraceuticals. This innovative technique, unveiled by Emma Walker, PhD’25, and Bogumil Karas, a professor at the Schulich School of Medicine & Dentistry, could lead to cleaner, cheaper sources of energy and health supplements.

Diatoms, which naturally store energy as oils, have long been of interest for their potential in producing biofuels and valuable compounds such as omega-3 fatty acids and antioxidants. The study, published in Nature Communications, highlights a more effective method for delivering DNA into these organisms, a key step in genetically modifying them for various applications.

Walker’s research focused on overcoming the challenges of DNA delivery to diatoms, which are protected by a silica shell known as a frustule. Previous methods were often slow and inconsistent. “People have long been interested in genetically modifying diatoms to make medicines, biofuels and other valuable compounds,” said Walker.

A pivotal moment in Walker’s research occurred when she tested a technique called electroporation, which uses electrical currents to create temporary pores in cell membranes. In her initial experiments, she observed the emergence of small colonies. However, when Karas repeated the process, he achieved over a hundred colonies, prompting Walker to investigate further.

Through a series of experiments, Walker discovered that older diatom cells exhibited a characteristic spherical shape, indicating a breakdown of their protective walls. This observation led her to hypothesize that the degradation of the cell wall could facilitate DNA insertion. By treating the cells with alcalase, an enzyme that disrupts the wall, she significantly enhanced the efficiency of DNA delivery, resulting in as many as 20,000 colonies in a single experiment.

The implications of this breakthrough are substantial. “This widens our ability to engineer the organism, which is important because one day we want to be able to create a strain of this diatom that is controlled by a synthetically built genome,” Walker stated. This capability is essential for advancing the development of biofuels and health products derived from diatoms.

The study also explored a low-cost chemical method for DNA insertion using polyethylene glycol (PEG), which proved to be more effective once the cell wall was compromised. This approach makes the technology more accessible, allowing laboratories to avoid expensive electroporation equipment.

Researchers further discovered that diatoms could assemble large pieces of DNA within their cells. “Suddenly, we could deliver very large pieces of DNA, not just small fragments,” Walker noted. This advancement has the potential to accelerate research timelines significantly. Karas emphasized the efficiency of the new method: “Instead of spending up to a few weeks moving DNA through bacteria before it reaches a diatom, we can now introduce the synthetic DNA directly.”

The techniques developed in this study have already been adapted for another diatom species through collaboration with Dr. Thomas Mock at the University of East Anglia in the UK. This international partnership brings scientists closer to the goal of resynthesizing DNA for greener energy technologies and innovative health solutions.

Walker’s findings demonstrate that some of the most significant advances in science come from unexpected observations and the curiosity to explore them. “Sometimes the biggest advances come from noticing something unexpected and asking why,” she said.

As research continues, the potential for diatoms to contribute to sustainable energy and health solutions appears brighter than ever. The work conducted at Western University represents a significant step forward in harnessing the capabilities of these remarkable organisms.