Science roundup

Last update: October 31, 2009 - 6:34 PM

ROTTEN TOMATOES, OR A SALMONELLA BREAKTHROUGH?

The 10 tomatoes sitting in a Tupperware tub at the Food and Drug Administration seem to be doing nothing more than rotting slowly. But an invisible battle is raging on the surface of the fruit, with provocative implications for food safety and the war humans have been waging against bacteria for a century.

"This is the wrestling ring," said Eric Brown, a microbiologist at the FDA's Center for Food Safety and Applied Nutrition, as he clicked open the lid. "This is the smack-down."

Working in a College Park, Md., laboratory, Brown and a team of FDA scientists trying to prevent salmonella contamination in tomatoes have stumbled upon what they believe are powerful, naturally occurring "good" bacteria that can slaughter the "bad" bacteria that have become a persistent problem in fresh fruits and vegetables because they harm humans.

Brown presented his initial findings at an international conference recently in France. "The beauty is that we take something alive and organic and put it back into the field, and by itself, it will kill other bacteria. We're right on the edge of this," he said.

While Brown's findings haven't been applied outside the laboratory, in his experiments the microorganisms obliterate not only salmonella on tomatoes but also several other pathogens blamed for food-borne illnesses, including listeria and E. coli O15:H7.

"It's a phenomenal finding he's got," said Steve Rideout, an assistant professor of plant pathology at Virginia Tech, who has allowed the FDA team to take tomato samples from the university's 200-acre research farm.

Salmonella has become a leading cause of food-borne illness in the United States. Once largely associated with poultry and eggs, the bacteria live in the intestines of animals. But recently, the bacteria are increasingly in fruit and vegetables, for unknown reasons.

Salmonella causes about 1.4 million cases of food-borne illnesses and more than 500 deaths a year in the United States, according to the Centers for Disease Control and Prevention.

NOT QUITE A WORLDWIDE WEB

In time for Halloween, we have two new discoveries about one of the creepiest crawlers around: the spider.

The largest orb-weaving spider ever seen has been found in Madagascar and Africa. The Nephila komaci, about 1 1/2 inches across with a 5-inch leg span, spins webs as large as 3 feet in diameter. A team led by Matjaz Kuntner of the Slovenian Academy of Sciences in Ljubljana reported the finding in the online journal PLoS One.

A vegan spider has been found in Mexico. Entomologist Christopher J. Meehan, now at the University of Arizona but then a graduate student at Villanova University, observed the Bagheera kiplingi (named in the late 1800s after the panther in Rudyard Kipling's "Jungle Book") ignore ants covering an acacia plant, crawling over them to instead eat nectar from the tips of leaves. Repeated observations showed the spider subsists almost entirely on the plant, although it occasionally snacks on ant larvae.

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Blog: Patent Pending

Lights out at U energy conference. Irony police notified.

Just as Lawrence Kazmerski, a top official at the National Renewable Energy Laboratory, was about to give the keynote address at the University of Minnesota's annual E3 conference at the RiverCentre in St. Paul, the lights went out, bathing the audience in darkness and a deep sense of irony.