The bacterial factor in wood decay

Summary Bacteria and actinomycetes are probably the most common wood-inhabiting microorganisms, certainly they are the most adaptable in terms of environmental influences. When considering them as factors in wood decay they may be roughly classified into four groups for convenience and ease of comparison. 1. Those bacteria which affect the permeability to liquids of wood but have no significant effect on strength properties.—2. Those types which attack the wood structure.—3. Bacteria which only function as integral members of the total microflora and are associated in the ultimate breakdown of the wood.—4. The passive colonizers which have no effect upon the wood at all but which have a marked influence on the remainder of the population by their antagonistic activities.—As bacteria and actinomycetes cetes have previously been held to be of minor importance in the field of wood degradation, these microorganisms are discussed in terms of the above four groups in an attempt to bring out their true importance.