Biodegradation of a biocide (Cu-N-cyclohexyldiazenium dioxide) component of a wood preservative by a defined soil bacterial community.
The wood protection industry has refined their products from chrome-, copper-, and arsenate-based wood preservatives toward solely copper-based preservatives in combination with organic biocides. One of these is Cu-HDO, containing the chelation product of copper and N-cyclohexyldiazenium dioxide (HDO). In this study, the fate of isotope-labeled ((13)C) and nonlabeled ((12)C) Cu-HDO incorporated in wood sawdust mixed with soil was investigated. HDO concentration was monitored by high-pressure liquid chromatography. The total carbon and the δ(13)C content of respired CO(2), as well as of the soil-wood-sawdust mixture, were determined with an elemental analyzer-isotopic ratio mass spectrometer. The concentration of HDO decreased significantly after 105 days of incubation, and after 24 days the (13)CO(2) concentration respired from soil increased steadily to a maximum after 64 days of incubation. Phospholipid fatty acid-stable isotope probing (PFA-SIP) analysis revealed that the dominant PFAs C(19:0)d8,9, C(18:0), C(18:1)ω7, C(18:2)ω6,9, C(17:1)d7,8, C(16:0), and C(16:1)ω7 were highly enriched in their δ(13)C content. Moreover, RNA-SIP identified members of the phylum Acidobacteria and the genera Phenylobacterium and Comamonas that were assimilating carbon from HDO exclusively. Cu-HDO as part of a wood preservative effectively decreased fungal wood decay and overall microbial respiration from soil. In turn, a defined bacterial community was stimulated that was able to metabolize HDO completely.
BAM, Federal Institute for Materials Research and Testing, IV.1, Biology in Materials Protection and Environmental Issues, Unter den Eichen 87, DE-12205 Berlin, Germany.
Désirée
D
Jakobs-Schönwandt
Helena
H
Mathies
Wolf-Rainer
WR
Abraham
Wolfgang
W
Pritzkow
Ina
I
Stephan
Matthias
M
Noll
D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D001711:Biotransformation; D002247:Carbon Isotopes / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D016000:Cluster Analysis; D003300:Copper / Q000378:metabolism*; D003510:Cyclohexanes / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004202:Disinfectants / Q000378:metabolism*; D007094:Imides / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013194:Staining and Labeling / Q000379:methods
D002247:Carbon Isotopes; D003510:Cyclohexanes; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004202:Disinfectants; D007094:Imides; C469872:N-cyclohexyl-diazeniumdioxide; D012336:RNA, Ribosomal, 16S; D003300:Copper