Chemical changes in wood degraded by bacteria

Archaeological wood and wood from foundation piles that were decayed mainly by bacteria was analysed chemically. It was found that with increasing decay the relative lignin concentration increases, as does the concentration of nitrogen and phosphorus. The lignin analyses (Klason lignin) were performed following the relevant TAPPI standards. These outcomes were confirmed by much less laborious FTIR measurements, which are seen to be a good tool for getting an indication of the level of bacterial attack of wood. Due to the ability of the microorganisms to degrade mainly polysaccharides, the hemicellulose and cellulose content decrease with increasing decay. The amount of phenolic compounds in waterlogged wood was considerably lowered, whereas the ash content increased due to the very long water storage conditions.