Bacteria as Important Degraders in Waterlogged Archaeological Woods

Identification of bacterial cultures from archaeological wood using molecular biological techniques

“…The present work has demonstrated what had been previously postulated by Nilsson and co-workers (Kim et al, 1996) and Blanchette and co-workers (Blanchette, 2000), that archaeological woods contain living bacteria. The 16S rDNA identiÿcation showed that a wide range of bacteria inhabited the degraded archaeological wood examined.…”

“…The degree of preservation of buried wooden artefacts depends upon the nature of the environment at the archaeological site. Cold, dark and near anaerobic conditions result in slower degradation (Blanchette, 2000;Kim et al, 1996;Powell et al, 2001). With the ever-increasing discovery of archaeological sites, but lack of funds for excavation and conservation, it is becoming common to consider either in situ preservation or reburial of the archaeological objects (Bergstrand, 2002;Brunning et al, 2000;Gregory et al, 2002;Mouzouras et al, 1990;Olsson, 2001;Pournou et al, 1998).…”

“…In the case of ash wood, the density of the archaeological objects was around 0:1 g=cm 3 . It is widely accepted, that bacteria are the main degraders of archaeological wood under near-anaerobic conditions (Bj ordal et al, 1999(Bj ordal et al, , 2000Blanchette and Ho mann, 1994;Blanchette, 2000;Daniel and Nilsson, 1997;Gregory et al, 2002;Kim et al, 1996;Kim and Singh, 2000;Powell et al, 2001). As it has not been possible to isolate these bacteria by conventional methods (Bj ordal and Nilsson, 2002;Kim and Singh, 2000;Nilsson and Daniel, 1983;Schmidt and Liese, 1994), the identiÿcation of bacteria that degrade wood under such conditions has been based mainly on the micromorphology of the decay pattern (Daniel and Nilsson, 1986;Daniel and Nilsson, 1997;Eaton and Hale, 1993;Schmidt and Liese, 1994;Singh et al, 1990;Singh and Butcher, 1991).…”

Bacteria and lignin degradation

“…They produce minute tunnels to migrate through the cell wall. Erosion bacteria are responsible for the predominant form of degradation in waterlogged archaeological wood, since they seem to tolerate nearanaerobic or fully anoxic environments (Kim et al, 1996;Björdal et al, 1999). Erosion bacteria are typically rodshaped, and they attack the wall from the lumen into the secondary walls singly or in small groups (Holt, 1983).…”

Preservation, storage and display of waterlogged wood and wrecks in an aquarium: “Project Aquarius”

“…For wooden object of historical significance, this will lead to a total destruction of the important surface layer which often contain unique information in form of ornamentation and toolmarks. However, wood in a near-anaerobic waterlogged environment is degraded very slowly by erosion bacteria exclusively (Björdal et al, 1999;Blanchette et al, 1990;Kim et al, 1996), and these bacteria do not have the same destructive effect on the wood material. Low oxygen concentrations inhibit microbial degradation of wood (Björdal et al, 2000), and wood exposed in a waterlogged oxygen free environment has so far shown no indication of microbial degradation (unpublished results).…”