| A Gliocladium virens strain RCEF4099 with high agricultural activity from Anhui provincial key laboratory of Microbial Control was selected, and the anti-fungal activity of the metabolite from RCEF4099 was investigated in this paper,including the experiments such as determination of biological indicators, anti-fungal test, optimization of fermentation medium and conditions, indoor pot experiment, mechanism of inhibitory strains, purification and identification process of the bioactive components.Firstly, this experiment determined the growth rate and chitinase enzyme activity of strain RCEF4099. By measuring the diameter of colony growth, the RCEF4099 strains can be seen grown fast, and the fourth day is the fastest growth day, the diameter of colony reached a diameter of 9cm in the fifth day. measured chitinase activity of RCEF4099 in eight days. Chitinase activity started expressing in the second day, Reached a peak on day 7, the activity began to decline after the peak.Secondly, this experiment studied the activity of a green Gliocladium virens strain RCEF4099 against plant pathogenic fungi. To study the antifungal activity of a green Gliocladium virens RCEF4099 against Botrytis cinerea, Fusarium graminearum, Bipolaris maydis, Rhizoctonia cerealis, Peronophthora litchii, Glomerella cingulat, Sclerotinia screrotiorum, Rhizoctonia solani by plate confrontation method and cup-dish method. The result showed that this strain had the highest inhibitory effect on Botrytis cinerea .Thirdly, based on the activity screening, effects of nutritional and non-nutritional factors on the active compounds production of the strain RCEF4099 were studied. Based on the anti-activity, the liquid fermentation condition was optimized. The results showed that the optimum medium components were : glucose 4% , commercial sugar 0.5% , white sugar 1.5% , K2HPO4 0.02% ; the optimum culture conditions were: culture medium amount 40 / 100 ml (V / V) flask , inoculum 10% (V / V) , fermentation period 5 day , shake rotation 160 r/min.When strain RCEF4099 was subcultured for 6 generations, its stability was steadiness. Subcultured from 7th generation to the 10th generation, its stability was slowly felled, the inhibitory diameter of the 10th generation decreased only 1.7mm compared with original strain . Through the research of stability of the fermentation products of RCEF4099 to heat , acid and alkali , the fermentation of RCEF4099 had a high anti-fungal activity to Botrytis cinerea at 60℃, and it is stable to acid .Through the fermentation of Gliocladium virens on spores and mycelial to explore the mechanism of inhibition. The strain RCEF4099 has strong inhibition of spores germination. After treatment, the rate of abnormal spores are higher. Hyphae of the pathogens would also have teratogenic effect.The indoor potted plants experimental showed that the strain RCEF4099 had a higher protection and treatment on Botrytis cinerea.Finally, comparison of extraction solvents and conditions, physical and chemical characters tests of the activity components, an optimal extraction processing was obtained as follows: firstly, the liquid culture was condensed at 50℃to 1/5 volume of the broth. Secondly, 3 times 95% ethanol was added to remove large molecule impurities such as polysaccharide. Thirdly, supernatant was condensed and extracted with 2 times of Acetone for 3 times. The Acetone extracts were condensed to dryness. The concentrated substance was crude bioactive product.HPLC-DAD-HRMS-Bioassay and bioactive guided isolation was done to determine the sturcture of the active compound. High resolution MS and DAD analysis revealed that the compound molecular weight is 104, and the molecular formula is C8H8.
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