Isolation, Identification, and Herbicidal Activity of Metabolites Produced by Pseudomonas aeruginosa CB-4

• Main Authors: Juan YANG, Hong-zhe CAO, Wei WANG, Li-hui ZHANG, Jin-gao DONG
• Format: Article
• Language: English
• Published: Elsevier 2014-08-01
• Series: Journal of Integrative Agriculture
• Subjects: Pseudomonas aeruginosa; bioherbicide; biocontrol; HSCCC; HPLC
• Online Access: http://www.sciencedirect.com/science/article/pii/S2095311913606954

CB-4, a bacterial strain with highly effective herbicidal activity, was isolated from infected corn leaves. Through morphology, physiological and biochemical tests, and 16S ribosomal DNA gene sequencing methods, CB-4 was identified as Pseudomonas aeruginosa. We conducted activity-evaluation experiments in the laboratory to assess the herbicidal potential of metabolites produced by strain CB-4. Crude extracts of strain CB-4 have high inhibition activity on Digitaria sanguinalis. In general, the root and shoot growth parameters of D. sanguinalis were significantly reduced by metabolites of strain CB-4. The IC50 of the culture filtrate extracts for the radicula and coleoptile of D. sanguinalis were 0.299 and 0.210 mg mL−1, respectively. Component 2 of the herbicidal activity of the crude toxin from strain CB-4 was successfully purified for the first time by using high-speed counter current chromatography with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (4:5:4:5, v/v) and high-performance liquid chromatography. We concluded that the metabolites of strain CB-4 have the potential to be developed as a microbe-based herbicide.