Luminescence of wood samples during long-term storage

Abstract

The present study describes changes in the mycelium of the fungus growing on the luminescent wood collected on Borneo Island in early December 2013 that occurred during 31 months of storage. The study shows that wood samples retain their ability to emit light, forming two types of luminescent mycelium: surface mycelium and aerial mycelium. The hyphae of the surface mycelium form on the surface of the wood sample and then spread over the surface of the polyethylene bag or over the surface of the bottom of tissue culture flasks containing the samples. The aerial mycelium develops later and only in tissue culture flasks, forming biomass composed of local interlaced hyphae, growing upward. The surface mycelium is characterized by non-uniform "flickering" luminescence along the hyphae. There is no diurnal periodicity in the luminescence of this fungus, but luminescence is increased by mechanical disturbance or exposure to ultraviolet radiation. The local impact of these factors causes an increase in luminescence of the mycelium regions that have not been directly affected. It has been assumed that the variable level of luminescence is an individual trait of this fungus species. The results obtained in this study suggest that luminescent wood found on Borneo Island contains mycelium of a fungus species, whose luminescent properties are essentially different from those of the fungi described in the scientific literature.