Isolation And Identification Of Biological Preservative Bacteria After Picking Snap Beans

Snap bean is one of the most popular quality vegetable in Northeast China, due to its short storage period, limiting the people to eat. Now in Heilongjiang province white snap beans as the research object, from storage during the decay of the pods and the onset of pod screened main spoilage bacteria and biological preservative bacteria, and the physiological, biochemical and molecular biological identification, further research on the biological preservative bacteria and spoilage bacteria antagonistic, demonstrating the inhibitory effect of biological preservative bacteria screening of predominant spoilage bacteria in snap beans. The results are as follows:Selected northeast white snap beans, after storage at room temperature, the corruption and on spoilage bacteria were isolated by dilution and streak plate separation method, respectively, 12 strains of spoilage bacteria were isolated. According to the morphological characteristics of main bacteria and fungus as two judgment; analysis of 18S rDNA gene sequencing of the spoilage bacteria, determine the main spoilage bacteria rot for Botrytis cinerea (Botrytis cinerea).Never rotting pod surface sampling by dilution and streak plate separation method for isolation of microorganisms on the surface,8 strains of bacteria; screening for the biocontrol of snap bean in 96 well plates; 12 strains of spoilage bacteria hanging liquid which is respectively connected to a 96 well plate, then the income 8 strains points don't access the well microtiter plates at 37? after cultured for 48h; orificing bacteria suspension medium is corresponding to the immigration enzyme labeled board at 480 nm of ceiling light value determination, get F3 bacteria light absorption value of 0.338, the inhibitory effect was best. According to the morphological, physiological, biochemical and 16S rDNA gene sequencing analysis and identification of the F3 for Enterobacter cloacae. Due to many reports of Enterobacter cloacae showed no obvious acute toxicity and sensitization.The plate confrontation test of F3 Enterobacter cloacae and corruption of Botrytis cinerea grounding resistance are studied, the bacteriostatic circle the F3 Enterobacter cloacae of spoilage bacteria maximum inhibition zone diameter for 1.17 cm. The F3 Enterobacter cloacae and spoilage bacteria of Botrytis cinerea cultured for 48h, scanning electron microscope (SEM) results for F3 Enterobacter cloacae can inhibit the growth of spoilage bacteria mycelium, and the emergence of Botrytis cinerea hyphal cell inclusions spillover, hyphal distortion phenomenon.To train a large number of F3 Enterobacter cloacae, beef extract peptone medium as basic medium, to determine the optimal carbon source for lactose, nitrogen source of pancreatic peptone, inorganic salt KH2PO4; optimal cultivation base amount:lactose as 5g/L, tryptone is 20g/L, KH2PO4 of 18g/L could be fixed by response surface method test; culture conditions by orthogonal test result:the culture temperature of 40?, training time is 72h, pH is 7, inoculation quantity 5%. Under this condition, the number of live bacteria F3 in Enterobacter cloacae:6.13* 106cfu/mL.