Study On Inhibiting Mechanism Of Antiyeast Substances Produced By Lactobacillus

Two strains of lactobacillus ALAC-3 and ALAC-4 being of strong antiyeast ability were studied. Taking Candida albicans as the indicator strain, the interaction of antiyeast substance produced by lactobacillus and yeast DNA was investigated by ultraviolet spectrometry and fluorescence spectrometry. The effect of antiyeast substance on the ultrastructure of yeast was determined by scanning electron microscope and transmission electron microscope. The effect of antiyeast substance produced by Lactobacillus on the enzyme activity of respiratory system of yeast were determined too by ELISA. The results were showed as follows:(1) The ultraviolet absorption value was decreased significantly and hypochromism were observed after adding anti-bacterial substances. With the extension of time, the ultraviolet absorption value was increased and hyperchromism were observed.(2) The fluorescence intensity was decreased after adding anti-bacterial substances. When the anti-bacterial substances and EB-DNA were reacted with each other, the fluorescence intensity was decreased significantly. And the fluorescence intensity was increased after EB and anti-bacterial-DNA was reacted. It indicated that there was the competition of anti-bacterial-DNA and EB-DNA in the solution system. The relative fluorescence intensity was increased with the increase of the volume of NaH2PO4 after adding NaH2PO4 into anti-bacterial-DNA system.(3) The antibacterial substances produced by two strains of Lactobacillus had effect on the ultrastructure of the yeast. The results of scanning electron microscope showed that the shape of the yeast cells were deformed seriously with the increase of time, and the cell walls were lacked. The holes appeared on the cell surface and the partial cell structure was incomplete. Transmission electron microscopy showed that the cell wall was destroyed seriously with the increasing of the time and the content of the cell was dissolved.(4) The antibacterial substances produced by two strains of Lactobacillus had effect on the activity of succinate dehydrogenase and malic dehydrogenase in the yeast respiratory system. The average specific activity of SDH and MDH were less than that in the blank control group.The above results showed that the antiyeast substance produced by lactobacillus had the effect on the DNA, ultrastructure, enzyme activity of respiratory system of yeast. So yeast cannot grow and multiply normally.