Research On Physiological Regulation Mechanism Of Antaganostic Yeast

Bio-control is one of the main technology to prevent decay of post-harvest fruit and vegetable. This study was carried on original yeast strain BH-03which discovered has the antagonistic activity was mutagenized to improve its antagonistic activity, the biological activity was tested "in invo" on the pathogenic fungi Fusarium of tomatoes brown rot was tested too.The original yeast strain BH-03was mutagenized under the UV with alternating light and dark and it was investigated that the survival rate was85.42%with the5.0×105per milliliter yeast suspension after2minutes’ UV,3hours’ lights and followed3minutes’UV. The mutants M and N yeasts selected after the combined action of UV were better than the original yeast strain BH-03’s. The biocontrol efficacy of the antagonist to disease caused by wound in tomato fruits was investigated too. It was found that the diameter of the streak diseased decrease13.93%by the M yeast vaccinated, and the spores were badly inhibited.Compared with the original one, the mutants M and N were of difference from the colonial morphology. The membrane shapes in the liquid of the land M,and the cell’s morphology of the N were very different with the BH-03. The logarithmic phase of the M yeast was7hours, while the N yeast arrived at the stabilization period separately grows for6hours later.This paper adopts Native-PAGE, using different concentration of colloid chitin-induced antagonistic yeasts M, N which has been found in the laboratory.From the perspective of resistance-related enzymes, there are discussed using exogenous substances induction improve the feasibility of antagonist yeast biological activity and antibacterial mechanism.The results showed that by ex vitro,the optimal concentration of colloid chitosan of antagonistic yeasts M, N are1.0%and0.5%. And isoenzyme analysis and activities of superoxide dismutase(SOD)、peroxidase,(POD) and polyphenol oxidase(PPO) were used to show that PPO isoenzyme activity significant changes. Antagonistic yeasts M has more significant effects on the change of the SOD and PPO isoenzyme activities than antagonistic yeasts N.In conclusion, on the basis of the UV mutagenesis technology, which combined with the outer material induction, we can effectively improve antagonist effection of the new antagonist yeast,provided the basis for the production.