USDA research on Stachybotrys

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http://www.ars.usda.gov/is/pr/2004/040618.htm

Indoor " Black Mold " Fungus Has Unexpected Relatives

By Peabody

June 18, 2004

Until now, scientists didn't know how to classify Stachybotrys chartarum,

the black mold that can grow in humid, indoor environments and is often

associated with " building sickness. " But an Agricultural Research Service

scientist recently found that the toxin- producing fungus comprises a

brand-new family within the order Hypocreales.

ARS mycologist A. Castlebury discovered that Stachybotrys' closest

relatives are actually members of the genus Myrothecium, fungi that cause

serious diseases in crop plants and invasive weeds. To determine this

relationship, Castlebury and her colleagues at the ARS Systematic Botany and

Mycology Laboratory in Beltsville, Md., sequenced and analyzed five genes of

Stachybotrys species and similar fungi.

Stachybotrys thrives on wet, cellulose-rich materials and can become

airborne. It also produces metabolic byproducts known as mycotoxins. A class

of these, known as macrocyclic trichocenes, are especially potent and have

been linked to serious illness in humans and livestock.

Up to now, when checking for fungi that produce harmful mycotoxins,

environmental engineers and others have generally tested houses and

buildings for the presence of Stachybotrys alone. But, according to the new

finding, a possible source of toxic macrocyclic trichocenes are also fungi

of the genus Myrothecium.

Despite the concern surrounding the presence of toxin-producing fungi in

homes, Stachybotrys and its relatives are relatively harmless when found in

nature. It's when they occur inside of artificially airtight spaces, with an

abundance of moist cellulosic materials, that the accumulating toxic

chemicals can reach high concentrations.

In a natural setting, moist, densely cellulosic material is scattered, and

mycotoxins produced by the fungi simply diffuse into the air.

ARS is the U.S. Department of Agriculture's chief in-house scientific

research agency.

Larkin, Executive Director

Mold Relief, Inc.

www.moldrelief.org

405-590-6372