Scientist solves secret of bee bread.

Scientist solves secret of bee bread

A microbiologist has discovered the microbial ingredients honeybees embed in the nutrient-packed pollen derivative known as bee bread.

Martha A. Gilliam of the U.S. Department of Agriculture's Carl Hayden Bee Research Center in Tucson, Ariz., identified 107 molds, 81 yeasts and 29 bacteria in the bread while she and co-workers sifted through the yellow granules for proteins, lipids, vitamins, minerals, amino acids and enzymes.

Workers bees newly emerged from the comb must eat bee bread so their glands produce food for the queen and developing larvae, whereas older worker bees -- the foragers -- survive primarily on honey.

"We think bee bread is somewhat more nutritious than regular pollen, but until recently, we weren't sure what happened to it [after the bees collected it]," says Elton Herbert, a research entomologist at the Agriculture Department's Beneficial Insects Research Laboratory in Beltsville, Md.

Using standard chemical methods, Gilliam picked apart pollen on its path from plant to hive. She took samples from beeless almond trees, from the carrying basket on the bee's leg and from the combs in the hive.

"We found that as soon as bees touch the pollen on the plant, they are adding glandular secretions, microorganisms and either honey or nectar to make it sticky," Gilliam says. The added microbes produce enzymes that help release nutrients such as amino acids from pollen, and the organisms manufacture antibiotics and fatty acids that prevent spoilage. The bees also remove unwanted microbes from the pollen.

Gilliam aims to do more than satisfy scientific curiosity. "I am looking to give bees a complete diet," says Gilliam, who hopes to make bee bread herself in the next three to five years. Beekeepers today must use artificial supplements to keep bees alive through winters or when plants aren't blooming, and to boost bee populations in the spring when the crops are ready for pollination or honey production. "I'm hoping we can make a diet that is much better for bees -- because it's what they are going to eat in nature," she says. Moreover, artificial pollen supplements ar expensive and often carry bee diseases. "We haven't found any way to sterilize [the artificial pollen] without knocking out essential nutrients that make the pollen attractive to bees," Gilliam says.