Identification Of The Secondary Metabolites Of C.minitans Chy-1 And Its Disease Resistance Affected By Chitosan Oligosaccharide

C.minitans Chy-1 has been widely used for biological control as importance biocontrol agents, and products active substances. Several compounds have been found from the homologous strains of Chy-1. Few report the secondary metabolites of Chy-1 although it can inhibit several pathogenic bacteria. This experiment has got three compounds isolated from the secondary metabolites of Chy-1, and their bioactive were studied. On the other hand, the bioactive of Chy-1 is worse than other mutant strains of Coniothyrium.minitans. It is benefic to advance the resistance of Chy-1. According to the previous research, chitosan oligosaccharide has the capacity to enhance disease resistance of microorganism. So chitosan oligosaccharide is used for carbon source in Chy-1 culture to enhance the disease resistance. The results are as follows:1. Prepared fermented liquid through cultivate the strains of Chy-1, and then isolated by TLC and chromatographic column followed appropriate elution solvent. The bioassay guided the isolation. The bioactive experiment showed medium active against Xanthomonas oryzae and Sclerotinia sclerotiorum Aa367 of three compounds. However, the three compounds can’t kill pathogenic bacteria only inhibit their growth. Furthermore, previous report demonstrated that macrosphelide A and P were cell-cell adhesion inhibitors.2. Bioactive substances tested by HPLC for purity analysis, and their structure determined by FT-IR, LC-MS, 1D and 2D NMR, respectively. We finally got three bioactive compounds, they are:two know 16-member-macrolide, macrosphelide A and P, one new compound Sesquiterpenketone C.3. Cultivate the strains of Chy-1 under different medium with different concentrations of chitosan oligosaccharide, respectively. Analyze the effect of chitosan oligosaccharide on the growth of strains Chy-1, and production of chitinase and bioactive compounds. To know more about the whole changes of metabolic network of Chy-1 affected by chitosan oligosaccharide, GC-MS is used for explain these changes.4. After a series of testes showed that the strains of Chy-1 has been inhibited by high concentration of chitosan oligosaccharide while the production of chitinase increased. The production of bioactive compounds also increased in high concentrations of chitosan oligosaccharide according to the bioassay experiment. Furthermore, the metabonomics demonstrated that the chitosan oligosaccharide caused some changes on Chy-1, such as carbohydrate, aliphatics, sterols compounds, et.al.