Isolating metal-tolerant bacteria capable of removing copper, chromium, and arsenic from treated wood

Bioremediation of chromated copper arsenate-treated waste wood with one or more metal-tolerant bacteria is a potential method of naturally releasing metals from treated wood fibre. Sampling eight environments with elevated levels of copper, chromium, and arsenic resulted in the isolation of 28 bacteria with the capability of releasing one or more of the components from chromated copper arsenate-treated wood. The isolates represent 13 species of 8 different genera of soilinhabiting bacteria. Three isolates, Acinetobacter calcoaceticus FN02, Aureobacterium esteroaromaticum VV03, and Klebsiella oxytoca CC08, were able to release 98% of the chromium, which is the most difficult component of chromated copper arsenate to remove from treated wood. Bacillus licheniformis CC01 released the highest percentage of copper, 93%, from treated wood. Eleven isolates, including Bacillus licheniformis CC01 and Acinetobacter calcoaceticus FN 02, released 44% to 48% of the arsenic. Carol A. Clausen USDA Forest Service, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53705-2398, USA