不同光照条件对脱镁叶绿酸钠光敏抑菌活性的影响

脱镁叶绿酸钠是叶绿素代谢中间产物脱镁叶绿酸a的水溶性钠盐，具有良好的光敏抑菌活性。为探索光照条件对其抑菌活性的影响，采用菌丝生长速率法，研究在不同光照度、光波长及光照时间条件下，脱镁叶绿酸钠对忽视拟盘多毛孢Pestalotiopsis neglecta的抑制作用。结果表明:20 mg/mL的脱镁叶绿酸钠在照度为2 000 lx的白光照射下对菌丝生长的抑制率为83.7%，在黑暗条件下抑制率为77.0%，表明光照对脱镁叶绿酸钠抑菌活性有显著影响 (P < 0.05)；此外，白光的效果好于单色光；光照度及光照时间对抑菌活性也有显著影响，其中当照度为16 000 lx且光照时间为24 h时抑菌作用最强。

Photosensitive inhibition of sodium pheophorbide a against Pestalotiopsis neglecta under different light conditions

Sodium pheophorbide a (SPA) is a water-soluble sodium salt of pheophorbide a, an intermediate product of chlorophyll metabolism, which has good photoactivated antimicrobial activity. To investigate the effects of illumination conditions on its antifungal activity, the mycelial growth rate method was used to study the photoactivated inhibitory effect of SPA on Pestalotiopsis neglecta under different light intensities, light wavelengths and light durations. The results showed that, when treated by 20 mg/mL SPA, the inhibition rate of mycelial growth was 83.7% under white light with an illuminance of 2 000 lx, and the inhibition rate was 77.0% under dark conditions, which indicated that light had a significant effect on the antifungal activity of SPA (P < 0.05), and the effect of white light was better than that of the monochromatic light. In addition, light intensity and duration also had significant effects on the antifungal activity of SPA, and the strongest effect was observed when the light intensity was 16 000 lx and the light duration was 24 h.