Antimicrobial activity of some Pacific Northwest woods against anaerobic bacteria and yeast

Extracts of woods commonly used for animal bedding were tested for antimicr obial activity. Essential oils from Alaska cedar (Chamaecyparis nootkatensi s), western juniper (Juniperus occidentalis) and old growth Douglas fir (Ps eudotsuga menziesii) as well as methanol extracts of wood from these trees plus western red cedar (Thuja plicata) and ponderosa pine (Pinus ponderosa) were tested for antimicrobial activity against anaerobic bacteria and yeas t. The test microbes included Fusobactetium necrophorum, Clostridium perfri ngens, Actinomyces bovis and Candida albicans which are common to foot dise ases and other infections in animals. The essential oils and methanol extra cts were tested using a standardized broth assay. Only extracts of Alaska c edar and western juniper showed significant antimicrobial activity against each of the microbes tested. The essential oil of Douglas fir did show anti microbial activity against A. bovis at the concentrations tested. The metha nol extracts of the heartwood of Douglas fir and the sapwood of ponderosa p ine showed no antimicrobial activity. The major chemical components of west ern juniper (cedrol and alpha- and beta -cedrene) and Alaska cedar (nootkat in) were also tested. In western juniper, alpha- and beta -cedrene were fou nd to be active components. Nootkatin showed activity only against C. albic ans. The inhibitory activity in Alaska cedar oil was high enough to justify further efforts to define the other chemical components responsible for th e antimicrobial activity. Copyright (C) 2001 John Wiley & Sons, Ltd.