Biological control of sapstain fungi in Egyptian wood stores and infected trees

Using microorganisms or their secondary products, especially volatile organic compounds (VOCs), to control wood infection by fungi has been exploited in recent years. A total of 17 local microbial isolates were screened for growth inhibition of wood-pathogenic fungi on solid artificial medium. Lactobacillus plantarum was selected as the most active VOC producer since it reduced the growth of sapstain fungi by 60-90% and that of wood-degrading fungi by 20-60%. During the interaction between the majority of the tested wood-pathogenic fungi and VOCs emitted by L. plantarum on wood blocks, both hyphal growth and conidial formation were inhibited. It was also observed that loss of wood dry weight and wood strength due to the action of pathogenic fungi was decreased to negligible values by exposing wood blocks to VOCs emitted by L. plantarum. The VOCs produced were trapped using a simple method and quantified by GC/MS. The main constituents of the VOC profile were 1,2-benzenedicarboxylic acid, dibutyl ester, isopropyl myristate, n-nonadecane, octadecane and n-eicosane. This study also evaluated using gamma radiation to enhance microbial production of VOCs.