Identification Of Endophytic Bacteria From Sophora Alopeuroides And Metabolites Research

Endophytic bacteria was isolated from Sophora alopecuroides in xinjiang, which had obvious antagonistic effect on Fusarium oxysporum f. vasinfectum and Methicillin-resistant staphylococcus aureus (MRSA).Strain KDNB6 was identified by its physiological characteristics and 16S rDNA sequence. In accordance with this strain's analysis, various characteristics of it were similar to Serratia marcescens. Strain KDNB6 was identified as Serratia marcescens. Strain KDNB6 was prepared liquid fermentation technique for the optimization condition study. The results indicated that the optimal initial conditions are ferm growth time is 24 h-27 h in liquid fermentation as seed fluid and inoculation amount is 4%(V/V) of inoculum; the optimal fermentation periods is determined to be 72 hours based on the growth curve of KDNB6 in the fermentation tank, the optimal liquid fermentation medium composition for KDNB6 glucose 10 g/L, (NH4)2SO₄ 5 g/L, wheat bran 20 g/L, C₆H₅Na₃O₇·2H₂O 2.0 g/L, K₂HPO₄·3H₂O 0.2 g/L, FeSO₄·7H₂O 0.05 g/L and MgSO₄·7H₂O 1.0 g/L. The optimal fermentation condations are pH 7.0, T 28°C and in all orbital shaker at 200 r/m.An anti-MRSA active components produced in fermentation broth were separated and purified using Silica gel column chromatography and Sephadex gel column chromatography. Two active components in fermentation broth had antagonistic effect on Fusarium oxysporum f. vasinfectum.