Optimization of B16 endophytic strain culture for its control of ginseng Cylindrocarpon destructans

Abstract:

[Objective] To study the optimal fermentation conditions of antagonistic strain B16 isolated from ginseng root for improving the quantity and antibacterial activity of the bacteria, and test its control effect on ginseng disease. [Methods] The single factor test and orthogonal test were used in optimizing the fermentation media and the conditions, and the strain’s antagonistic effects to ginseng pathogenic fungus Cylindrocarpon destructans were tested with pot trails. [Results] Optimum fermentation media for B16 was: sucrose 1.00%, yeast extract 0.50%, MgSO4·7H2O 0.05%, FeSO4·7H2O 0.06% and NaCl 1.00%; and the optimum conditions are: pH 7.5, 35 °C, 5% 108?CFU/mL bacterium suspension, 40 mL/250 mL, 170 r/min and 48 h fermentation. The B16 fermentation broth shows antagonistic effect to ginseng pathogenic fungus C. destructans, the protection effect and curation effect are 64.8% and 58.6%, respectively. [Conclusion] Strain B16 has potential for C. destructans biocotrol.