Abstract:The present study sought to examine how sea buckthorn（SBT）oil impacts mitochondrial and overall functionality in Aspergillus niger.A.niger mycelia were treated with different concentrations of SBT oil.The mitochondria were extracted and their ultrastructure observed using transmission electron microscopy.In addition，the mitochondrial function of A.niger treated with different concentrations of SBT oil was assessed.The levels of reactive oxygen species and malondialdehyde，the changes of cell membrane potential，and the activities of the tricarboxylic acid cycle related enzymes，succinate dehydrogenase and adenosine triphosphatase，were measured.SBT oil induced mitochondrial damage in A.niger in a dose -dependent manner.The mitochondria treated with SBT oil showed obvious vacuolization，formation of abnormal vesicles，and the destruction of mitochondrial matrix structure，resulting in altered succinate dehydrogenase and adenosine triphosphatase activities，reduced mitochondrial membrane potential levels，and markedly elevated malondialdehyde and reactive oxygen species levels.Taken together，these findings suggest that SBT oil can damage mitochondrial membrane permeability，leading to mitochondrial structure destruction and impaired mitochondrial function.Thus，SBT oil may have antifungal activity.