Elimination and detoxification of softwood extractives by white-rot fungi.
The ability of several white-rot fungal strains to remove and detoxify acetone extractives (pitch or resin) in Scots pine sapwood was investigated in stationary laboratory batch assays. Fungal pretreatment provided up to 62% total pitch reduction and significant decreases in pitch toxicity. The best strains were Bjerkandera sp. strain Stereum hirsutum and Trametes versicolor that eliminated over 93% of the problematic triglyceride fraction and 58-87% of other lipophilic extractive classes in only 2 weeks. Fungal removal of the wood extractives was accompanied by a 7.4-16.9-fold decrease in their inhibitory effect, as determined in the Microtox bioassay. Wood pretreatment by Bjerkandera sp. and T. versicolor caused limited losses of woody mass (less than 4% in 4 weeks); whereas S. hirsutum led to somewhat higher mass losses (7% in 4 weeks). These results indicate the potential of white rot fungi to control pitch deposition problems in pulping and to reduce the aquatic toxicity caused by naturally-occurring lipophilic extractives in forest industry effluents.
Dorado
J
J
Division of Wood Science, Department of Environmental Sciences, Wageningen University, The Netherlands.
Claassen
F W
FW
van Beek
T A
TA
Lenon
G
G
Wijnberg
J B
JB
Sierra-Alvarez
R
R
D000096:Acetone / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D002473:Cell Wall / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005658:Fungi / Q000378:metabolism*; D012116:Resins, Plant / Q000378:metabolism*; D013261:Sterols / Q000378:metabolism; D014197:Trees / Q000382:microbiology*; D014280:Triglycerides / Q000378:metabolism; D014873:Water Pollutants / Q000378:metabolism
D005227:Fatty Acids; D012116:Resins, Plant; D013261:Sterols; D014280:Triglycerides; D014873:Water Pollutants; D000096:Acetone