FROM PONDS TO PETRI DISHES

Applications of Algae in Biotechnology

WRITTEN BY Zainab Fatima and Eventine Youngblood ILLUSTRATED BY Taryn Cornell

PHOTO BY Beatte Kim

When the COVID-19 pandemic swept the nation, many commercial industries neared collapse, while biotechnology companies like Pfizer and Moderna capitalized to push for rapid development of their respective vaccines. From developing pharmaceuticals, vaccines, and even cleaning supplies, the biotechnology industry plays a crucial role in developing a wide range of commercial products from various biomolecules. However, as research, development, and demand for these products increase, so do worries of the industry’s environmental sustainability. As a response to these concerns, researchers and governments alike are looking to maximize production of sustainable bioproducts and biofuels with hopes of eventually replacing unsustainable sources of energy.

Algae Evolution And Biofuels

In a major collaboration, UC San Diego’s Shurin Lab, Los Alamos National Labs, and the United States Department of Energy look towards algae as a sustainable alternative biofuel. As one of the most utilized organisms in biotechnology, algae is cultivated and typically utilized as a source of pharmaceutical and nutraceutical compounds such as biolipids, beta carotene, and chlorophyll. These compounds can be used directly as alternative energy sources and play a significant role in the development of other bioproducts.

At UC San Diego, PhD student Ugbad Farah studies ecology and sustainability in Dr. Jonathan Shurin’s laboratory. Farah began studying moss variation in extreme environments as a master’s student at Cal State Los Angeles, where she discovered that environmental factors such as elevation, precipitation, and distance significantly altered the appearance of the same species of plant. With this experience, she proposed a question: does adaptation to environmental variations yield measurable differences in the raw production of biomolecules? Inspired by this question, Farah continued her research career in the Shurin Lab with an emphasis in biofuel production and sustainability in the field of biotechnology. She now works as a leading scientist on various algae projects including the Department of Energy collaboration.

In her primary project, Farah studies the directed evolution of algae populations. Directed evolution describes the phenomenon in which researchers guide the evolution of a population by tailoring environmental conditions over an extended period of time to understand how these conditions influence evolution. In her research, Farah studies whether evolution of algae under different conditions impacts the bioproducts it produces. To achieve this, Farah cultivated and utilized a controlled strain of algae, Nannochloropsis oceanica for 16

Extraction of Valuable Biomolecules from Algae

Algae can be cultivated under specific conditions to rapidly multiply and form colonies. These colonies can then be harvested to extract valuable biomolecules.

experimental groups, each with different treatments. This species was selected for its rapid reproduction cycle, as populations tend to double in as little as 19 hours. This rapid reproduction allows for changes in the phenotypes, or physical characteristics, of the algal populations, to be observed and compared between the 16 groups as they respond to different temperatures, carbon dioxide levels, nutrients, and lighting. After many generations, Farah plans to analyze each population to see how they change from their shared ancestor. Based on any observable and quantifiable changes, she can recognize trends in density, growth rates, fatty acid content, and size.

NEW POS-SEA-BILITIES

Farah’s research with algal evolution helps companies understand how to maximize algae for commercial use in biofuels. But once grown, how else can algae be applied for commercial purposes? The Mayfield Lab at UC San Diego’s California Center of Algae Biotechnology uses genetic engineering to explore different applications of algae in the production of nutritionally dense algae and biopolymers, or large molecules in biological systems synthesized from smaller repeating units.

As a PhD student at the Mayfield Lab, Crisandra Diaz researches how to genetically synthesize nutritionally dense algae with higher lipid and protein content. To induce mutations within algae strains, she uses techniques called UV mutagenesis and selective algae breeding that aim to create mutations with more lipid and protein content. In UV mutagenesis, an oven exposes individual colonies of microalgae to UV light that damages the DNA and forms mutations within the algae. The algae strains proceed through sequencing to identify which strains contain the most desirable mutations for lighter lipid and fat content. After identifying the mutations, Diaz and her team perform tests involving characterization and sequencing to determine which algae strains can breed together, in hopes of optimizing the breeding of algae with higher lipid and protein content. By maximizing lipid and protein content in algae, genetically modified algae can act as a food source in low-resource environments to help combat the global hunger crisis. Algae can act as a sustainable alternative form of nutrition in low-resource environments, due to its ability to regrow in the same area of water and take up less energy and land to grow than other food sources.

In addition to research, Diaz and the Mayfield Lab also synthesize a sustainable alternative to polyurethane plastics known as algal-based bioplastics. In most commercial uses, such as insulation, adhesives, and car manufacturing, polyurethane is made from petroleum and other less sustainable sources, creating a need for developing methods from more sustainable sources such as algae.

The Mayfield Lab first derived algal polyurethane foam from compost and passaged the foam to a carbon-free media to make the foam the only carbon source. After passaging and discovering bacterial colonies on the foam, the researchers sequenced the proteins from these bacterial colonies and tested if the bacterial enzymes break polyurethane bonds. The ability to break polyurethane bonds is an important feature for these bacterial enzymes since it allows the degradation of polyurethane plastics. To test whether the bacterial enzymes can break the bonds in polyurethane, the researchers used a fluorometric assay, where they mixed together the bacterial enzyme and the substrate with polyurethane bonds. The mixture then emitted a fluorescent light, signaling the breaking down of bonds in the substrate by a specific bacterial enzyme. The researchers repeated this process with other bacterial enzymes and other substrates with polyurethane bonds to compare the most biodegradable product. The research done on algae-based polyurethane foam is significant in improving the breakdown of algal-based polyurethane plastics. The algal-based polyurethane foam can use algal bacterial enzymes to break down further into smaller monomers. Monomers are small repeating units that can interact to form a larger molecule such as a polymer. These monomers can reform into a polymer that resembles the original foam structure, creating a bio-recyclable loop. By breaking down into monomers and rebuilding the molecule, algal-based polyurethane plastics can be recycled and still maintain the structural integrity of the original plastic product. This method is an improvement from other plastic recycling methods, such as heating or “mashing” that weakens the recycled product to a lower structural integrity than the original product.

Fueling The Future

Algae research provides a promising new avenue for introducing environmentally-friendly materials and products to the biotechnology industry, with applications in many areas of life. Algae can be used as a sustainable form of energy through the production of algae-based biofuels. Algae can also be used in other applications such as generating nutritionally-dense food or biodegradable plastics. The varied applications of algae in different sectors of the biotechnology industry open new opportunities to improve the environmental impact of current materials, food, and energy sources, and through continued research and development, algae will play a key role in the creation of a more sustainable future.

Analysis of Extraction

Based on the quantities of biomolecules extracted, conditions are then modified and applied to algal populations. These populations are then cultivated and compared to see which conditions offer optimal biomolecule harvests.

Dr. Shermin de Silva with Emily White

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