Identification Of Endophytic Bacteria SMY-2 From Rumex Crispus L.and The Study Of Antibacterial Activity

Endophytic bacteria has great potential in medicine?agriculture?environmental protection and food industry,so it has became researchers' research focus in recent years.The author did a research of strain NO.SMY-2 that isolated from a kind of Medicinal plants-Rumex crispus L.,This study focused on the Stability of metabolites?fermentation broth?the fermentation conditions?growth-promoting,and field efficacy of strain NO.SMY-2.The results were as follows:1.In the experiment,the antagonistic strain NO.SMY-2 was identified by morphology?physiological and biochemical characteristics.Then the strain NO.SMY-2 was identified as Bacillus amyloliquefaciens by analysis of the 16S r DNA sequence.2.Through the study we can find that the strain NO.SMY-2 performed high antagonist activity to most of phytopathogen,and the Bacteriostatic rate to Alternaria alternata?Alternaria solani?Monilinia fructicola even over 80%.3.we can get the results by the growth rate method that the strain SMY-2 the best basic culture medium was NYBD medium,the best carbon source is maltose,the best nitrogen source is Beef extract+Peptone,the optimal fermentation parameters were pH8.0 or 9.0;volume 150-200 m L,inoculation 3%-5%,culturing for 48h.4.The results of the strain SMY-2 stability of its metabolites study:when the pH in the range of 3 to 11 its bacteriostasis rate can reach over 80%;Within the temperature range of 15-121 its bacteriostasis rate can reach over 75%;strain treated by ultraviolet light 2-12hours its bacteriostasis rate can reach over 80%.These show the stability of the strain NO.SMY-2 in acid?heat and ultraviolet light are great.5.Promoting effect analysis showed that the strain SMY-2 10 times dilution of strain SMY-2 fermentation could promote germination rate of tomato seeds,and the strain SMY-2 fermentation could promote tomato plants' growing.