Screening microbial inhibitors of Pseudogymnoascus destructans in Northern China.

White-nose syndrome is caused by Pseudogymnoascus destructans, leading to the near extinction of multiple bat populations in North America. This fungal pathogen has also been detected in China, but the prevalence and loads are relatively low in the hosts and environment. Previous studies have screened bat skin microbiomes in China to identify microbes that inhibit the growth of P. destructans. However, there is limited information on bacterial genera that possess properties that inhibit P. destructans in bat cave environments in China, particularly regarding antifungal metabolic pathways. We isolated 29 bacterial strains that have the ability to inhibit growth of P. destructans from the skin of bats and soil samples in China. These strains primarily belonged to several genera, including Acinetobacter, Pseudomonas, and Serratia. Gas chromatography-mass spectrometry analysis identified volatile organic compounds from strains that inhibit P. destructans, showing that 100 µL of α-Pinene, 2-Undecanone, 2-Nonanone, 2,5-Dimethylpyrazine, as well as 10 µL Benzaldehyde and Thujone, completely inhibited the growth of P. destructans and caused morphological damage to the mycelium. The soluble secondary metabolites from the antagonistic strains indicated that the bioactive compounds were predominantly small-molecule organic substances. Whole-genome sequencing of these antagonistic strains revealed that the most enriched potential antifungal gene clusters were associated with bacteriocins, siderophores, and β-lactones. β-Lactones were the primary gene cluster against P. destructans, and chitinases may play a crucial role in the antifungal process.IMPORTANCEBat skin and environmental microbiota may influence the colonization and persistence of Pseudogymnoascus destructans, thereby potentially affecting the occurrence of white-nose syndrome. Examining differences in these gene clusters contributes to understanding variation in the capacity of bacterial groups to have characteristics that inhibit P. destructans. This study lays the foundation for further exploration and elucidation of the mechanisms by which bacteria from bat skin and roosting environments suppress P. destructans growth in vitro.