Bacteria Feast on Pollutants in Oil Petrolite Part of Effort Using Genetic Research vs. Sulfur

Article excerpt

Biotechnology is battling brimstone right here in Webster Groves.

At Petrolite Corp.'s headquarters, two companies are using genetically engineered bacteria to remove sulfur from oil.

If successful, they could combat one of nature's most abundant elements and pervasive pollutants.

Sulfur-laden crude oil is an expensive problem for oil companies because it corrodes refining equipment. When burned, this oil produces sulfur oxides that are linked to smog and acid rain.

But in the presence of certain bacteria, the sulfurous oil becomes a grand repast.

So Petrolite has joined a Texas company to see if biotechnology and oil-purification skills can produce a new way to make cleaner oil by creating bacteria with bigger appetites.

The driving force is Energy BioSystems Corp. of suburban Houston. Founded in 1989, the company is training a bacterium to pry away sulfur bound to petroleum - without damaging the quality of the oil.

The bacterium - Rhodococcus erythropolis - is found in soil and has a natural affinity for sulfur.

Manufacturers have used it for more than 40 years to produce items as varied as citric acid and vitamins, said Daniel J. Monticello, vice president of research and development for Energy BioSystems.

Around oil, Rhodococcus is a scavenger because it needs sulfur to survive. "We have to convince the bacteria that this is the most important thing they can do," Monticello said.

Energy BioSystems does this by manipulating the bacterium's genes, isolating sulfur-eating enzymes. The natural bacterium is not aggressive enough in producing the enzymes.

"We need to get the organisms to sprint," Monticello said. "Right now, they're jogging. When we started, they were crawling."

The jazzed-up bacteria are cultivated, mixed with water and then combined in a special reactor with a stream of high-sulfur oil.

The oil passes through the reactor; the bacteria chow down, pulling the sulfur from the oil.

The oil is funneled from the reactor while the sulfur byproduct is removed. The water and bacteria are recycled into the reactor.

That's how it works in the laboratory, and now it's being tested in a two-story pilot plant at Petrolite's headquarters. The pilot plant started in March, and the two companies conducted a tour for securities analysts and the media Tuesday.

Energy BioSystems officials say they will know by the end of the year if the pilot plant works well enough to build a full-scale plant. …