A comparative study of structural changes in loblolly pine wood following incubation with the fungus Physisporinus vitreus and the bacterium Bacillus subtilis

Abstract

ABSTRACT The fungus Physisporinus vitreus and the bacterium Bacillus subtilis are commonly used organisms in wood biotechnology to increase wood permeability. However, comparative researches on wood destruction by these biological wood decomposers are scarce, particularly from microscopic and chemical perspectives. This study aimed to compare the fungal and bacterial wood destruction patterns over time. Loblolly pine (Pinus taeda L.) heartwood samples were exposed to both organisms for six and nine weeks; microscopic and spectroscopic analyses of the incubated wood were performed, and mass loss of samples was calculated. Both organisms initially destroyed the pit tori and ray parenchyma cells, but B. subtilis was more selective in its consumption of wood components. It exclusively consumed hemicelluloses and free carbohydrates in wood, whereas the fungus destroyed all chemical components simultaneously. The digestion of bordered pits by B. subtilis was more selective than that by P. vitreus, making it a better choice for controlled wood destruction. By extending the exposure duration, the bacterial destruction pattern remained consistent, whereas fungal destruction spread to the secondary wall of the tracheids. Understanding the interactions between microbes and wood can lead to a more effective and efficient use of this natural resource.