UCLA Spotlight


Birgitte Ahring, Civil and Environmental Engineering

  • By Judy Lin Eftekhar, Reed Hutchinson
  • Published Mar 1, 2001 8:00 AM

The world is a better - and cleaner - place thanks to waste management expert Birgitte Ahring, UCLA Professor of Civil and Environmental Engineering.

Ahring is an internationally recognized authority in using anaerobic bacteria - bacteria that exists in an oxygen-free environment - to biodegrade waste. Fluent in English, French and German as well as her native Danish, she has traveled the world overseeing waste management projects for the United Nations.

Ahring's enthusiasm for the field of environmental biotechnology began in graduate school in the 1980s at the University of Copenhagen. At that time, advances in genetic engineering made it possible for the first time to clone difficult-to-cultivate microbes. While many of her colleagues headed for work in biotechnology companies, Ahring thought it would be much better to "save the world."

"I wanted to use waste to produce something useful," she said. "I found that very appealing."

When Ahring entered the field of waste management, aerobic bacteria - which use oxygen to metabolize - were already well-established for their ability to consume garbage as a food source. Ahring helped pioneer the use of anaerobic bacteria, using substances other than oxygen to metabolize. Anaerobes have proven especially effective in biodegrading hard-to-handle industrial and hazardous wastes.

"I'm fascinated with high-temperature bugs," Ahring said. Called "thermofiles" for their ability to thrive at higher-than-boiling temperatures, these bacteria biodegrade waste quickly. The anaerobic process has the added advantages of producing the biogas fuels methane and ethanol, which can produce electricity, and thermofilic digested sewage sludge, which can be used as an agricultural fertilizer.

Like a treasure hunter, Ahring is on a constant search for new anaerobes. She embarks on sampling expeditions at hot springs in places like Yellowstone National Park, where thermofiles thrive. Her graduate students accompany her, and sometimes also her two young sons. The most promising samples Ahring cultivates in her laboratory, genetically engineering them to work even better. She then adds them to her "microbe bank" of some 600 strains.

"I consider myself so fortunate," Ahring said. "There's so much going on in my area and so many new tools. This is a fascinating time."