Yeast and bacteria as biological control agents against fungal discolouration of Pinus sylvestris blocks in laboratory-based tests and the role of antifungal volatiles

This paper reports on the use of yeast as biological control agents against mould and blue-slain fungi in laboratory-based Pinus sylvestris sapwood wood block incubation rests. All 5 yeast isolates tested significantly reduced discolouration of wood surfaces by moulds and most were also effective against staining fungi. The 2 most promising yeast isolates also significantly reduced radial growth of selected mould and stain fungi in vitro solely through the liberation of volatile compounds. Five bacterial isolates were also tested fur antagonism toward mould and stain fungi and were effective biological control agents in wood block tests. Again, volatile production alone by the bacteria was shown to be sufficient to significantly reduce fungal growth in vitro. Most of the bacteria and yeasts significantly reduced wood discolouration by fungi when inoculated onto block surfaces 7 days before, or at the same time as the target Fungi, and in some cases even when inoculated 7 days after the fungi. The possibility of using yeasts as biological control agents to prevent wood spoilage during kiln drying and short-term storage at sawmills is considered.