ISO: “Boutique Algae”

Summer 2013

GOING GREEN: An environmentally friendly process links wastewater treatment and biofuel production.

Overreliance on fossil fuels, depletion of natural resources, and pollution control are among the greatest global challenges of our time.

Michael Betenbaugh, professor of chemical and biomolecular engineering, and Edward Bouwer, the Abel Wolman Professor of Environmental Engineering, have teamed up on a project that aims to address all three of these issues at once. Their goal is to engineer a commercially viable, environmentally friendly process that links wastewater treatment and biofuel production.

Here’s how it works: Algae can be used to feed on nitrogen and phosphorus in wastewater from a treatment plant, removing excess nutrients that might otherwise run off into our waterways. In turn, the lipids, or fats, in the algae can be extracted for the production of renewable biodiesel, an alternative to standard petroleum-based diesel fuel.

The challenge lies in finding the right algae for the job. While the exact number of algal species on earth is unknown, algae have been estimated at anywhere from 30,000 to more than 1 million species. “Two different strains of algae can be as genetically different as humans are from insects,” says Betenbaugh.

To complicate matters more, algae with high levels of lipids are the most effective for biofuel production, but algal species that can thrive in wastewater generally exhibit low lipid accumulation.

So Betenbaugh and Bouwer are on a quest to find “boutique algae” that can consume nutrients in wastewater and convert them into lipids. Identifying the right strain of algae for the job is crucial to the success of this project, which is supported by a threeyear $348,900 grant from the National Science Foundation.

Since the start of the project in fall 2012, Pavlo Bohutskyi, an environmental engineering doctoral student who came to Hopkins on a Fulbright Scholarship, and Julian Rosenberg, a chemical and biomolecular engineering doctoral student, have screened 100 naturally occurring strains of algae for growth and lipid productivity. To do so, they harvest the algae in small glass beakers filled with wastewater and test a variety of techniques to “coax” the algae to produce lipids. The team is also exploring the idea of genetically modifying algal strains to improve their cellular composition and increase their productivity.

Bouwer envisions a future in which nutrients—from wastewater, agricultural run-off, and other sources—are recycled just as paper, plastics, and electronic components are today. “Biofuels hold promise for reducing our dependency on fossil fuels and for combating pollution, but first we need to come up with a sustainable, cost-effective process that works on a large scale,” Bouwer says.