Chemical Mutation Of Streptomyces Purpeofuscus YSSPG3 Pesticide Resistance

To select the drug-resistant strain,the treptomyces purpeofuscus YSSPG3 was treated by chemical mutagen(Ethyl methane sulfonate,Sodium azide and 5-bromouracil)with different concentration,and then these mutation strains were screened out through the carbendazim and chlorothalonil,and determination of various indexes of the resistant strains,at last,selected the excellent resistance mutant strains and evaluated to kinds of pathogenic fungi,then synergistic use the resistant strain and pesticide,control effect on the pathogen.The results are as follows:1 After treated with chemical mutagenesis and chemical acclimation,selected 4 kinds of mutant strains tolerant to carbendazim were 3500mg/L,namely 2 kinds of mutant strains by the concentration of sodium azide mutagen concentration of 8,10mmol/L,and 2 strains after the addition of 10,20?L ethyl methyl sulfone(EMS)concentrate mutagenic treatment;5 kinds of mutant strains tolerant to chlorothalonil were 1500 mg/L,namely 2 strains by the sodium azide concentration of sodium azide mutagen concentration of 8,10mmol/L,and 3 strains after the addition of 10,20,40?L ethyl methyl sulfone(EMS)concentrate mutagenic treatment;2 With the starting strain Streptomyces purpeofuscus YSSPG3 sensitive control strain,the resistance level is 1,in the carbendazim pesticide processing,contrast the Ec50 of strain value is 180.18mg/L,the lethal concentration is 700mg/L,4 kinds of mutant strain in culture medium containing 3500mg/L carbendazim could grow colonies,with Ec50 value ranging from 3202.58 to 3722.20mg/L,the resistance level is from 17.99 to 20.66,while the drug-resistance of mutation strains which were induced by Sodium azide when concentration was 8 mmo/L were strongest;In pesticide processing of chlorothalonil,Ec50 value is 164.66mg/L,the lethal concentration is 500mg/L,5 kinds of mutant strain in culture medium containing chlorothalonil 1500mg/L can grow colonies,the Ec50 values ranging from 1301.97 to 1960.20mg/L,the resistance level is from 7.91 to 11.90,The sults of drug resistance experiment showed that the mutant strains which were treated by Sodium azide(8 mmo/L)had the bestresistance to chlorothalonil;3 Through the observation of several drug-resistant strains in determination of stability is the best by sodium azide mutagen concentration of 8mmol/L induced;all strains in the add of chlorothalonil,carbendazim culture medium on the growth rate slowed down significantly,and the fastest growth rate is the concentration of sodium azide mutagenesis was 8mmol/L;9 kinds of drug-resistant strains of spore production is the largest by adding 10?L ethyl methyl sulfonic(EMS)concentrate induced mutant strain after processing,is 3.03�109cfu/mL,but the spore germination rate is relatively small,the spore germination rate of the biggest is the concentration of sodium azide mutagenesis agent for 8mmol/L for the mutant strain after mutagenesis,is 21.34%;5 strains of chlorothalonil resistant mutant strains of spore production is the largest by sodium azide mutagen concentrations of 8mmol/L the mutant strain after mutagenesis,7.50�109cfu/mL,the spore germination rate is maximum,at 18.00%.But compared to start without mutagenic strain,9 kinds of resistance mutant strain system.all of the spore germination rate is significantly reduced.4 After the plate confrontation,found that 2 excellent resistance strains of 9 kinds of pathogenic bacteria has significant inhibitory effect,the addition of chlorothalonil,carbendazim medium also had a different degree of inhibition on 9 kinds of pathogenic bacteria,but the resistance of mutant strains and carbendazim,chlorothalonil collaborative use,stronger inhibitory effect on the pathogen.By sodium azide mutagen concentrations of 8mmol/L mutagenesis of carbendazim resistant mutant strain the Ec50 values of up to 3722.20mg/L,the concentration of sodium azide mutagenesis agent for 8mmol/L after mutagenesis of chlorothalonil resistant mutant strain the Ec50 values of up to 1960.20 mg/L,both in the production practice and carbendazim,chlorothalonil collaborative use of prevention and control of plant diseases,achieve better control effect,and to a certain extent,reduce the pesticide pollution to the environment.5 After a method of transparent for the determination of enzyme activity,found that the 9 kinds of Streptomyces purpeofuscus YSSPG3 mutant strains were net with chitinase activity.