Antibacterial Activity And Taxonomy Of Endophytic Bacteria Lsolated From Suaeda Salsa L.

Endophytic bacteria is a group of microorganisms which can inhabit healthy plant tissues without causing substantial harm to plants and with establishing a harmonious relationship. Recent studies have shown that endophytic bacteria have antibacterial, antiviral, antitumor, antioxidant and other biological activity. Endophytic bacteria and metabolites as a special resource have become an important resource library of researching and discovery natural drugs and bioactive components. It is also a hot field of microbiological research directions.Suaeda glauca bge is grown in saline soil, lake, river and coastal areas. As a typical indicator plants, it is an important model materials of salt tolerance genetic research in plants. The physiological and endogenous metabolism may present special characteristics because of the particular living environment. A broad-spectrum antimicrobial endophytic bacteria EB0901 strain had been isolated and selected from Suaeda glauca bge. The biological characteristics, identification, optimization of growth conditions and antibacterial activity had been studied. The results are as follows:1. Isolated and screened of endophytic104 strains endophytes had been isolated from 300 roots, stems and leaves of Suaeda glauca bge with the method of tissue surface disinfection of which bacteria 5 and fungi 99. A strong antagonistic endophytic bacteria from 5 with the method of confrontation by plate, number EB0901 strains.2. Morphology and taxonomy of EB0901Biological characteristics of EB0901:Thallus is rod-shaped in beef extract peptone culture medium, produce spores, week flagella, gram positive bacteria. Physiological and biochemical tests showed:catalase, starch hydrolysis, methyl red test were positive; V.P reaction, hydrogen sulfide were negative. It is facultative anaerobic. Reference to "Common Bacterial System Identification Manual" and "Berger Bacterial Identification Manual" eighth edition, EB0901 should be attributed to salt Bacillus.3. Optimization of growth conditions of EB0901Fermentation conditions of strain EB0901 is preliminary studied. Appropriate medium composition and culture conditions are defined. Under the conditions of yeast 5 g/L, starch 30 g/L, beef 6 g/L, (NH4)2SO4 0.2 g/L, peptone 10 g/L medium, inoculum dose 5%,35℃culture temperature, initial pH 7.0,0.5% NaCl concentration most suitable for the growth of strain EB0901. 4. Antibacterial activity of EB0901EB0901 strain and metabolites have a broad-spectrum antimicrobial. It has different antibacterial effect on 8 pathogen,6 bacteria and 5 mold. The inhibitory rate is more than 60% on Exserohilum turcicum, Scferotiniascferotiorm, Bipolaris, Gloeosporium piperatum. It has obvious inhibitory effect on Staphylococcus aureus and Bifido bacterium, reaching 67.03% and 60.53%. The inhibitory rate is 62.03% on Mucor. There is no significant antibacterial effect on Rhizopus. The study showed that:EB0901 strain has a good prospect for plant disease control.