[Algae-inhibitory effect and mechanism of plant source n-caprylic acid].

ABSTRACT

OBJECTIVE: To research the algae-inhibitory effect and mechanism of a plant source n-caprylic acid extracted from coconut oil on M. aeruginosa. METHODS: The M. aeruginosa were treated with 0, 12.5, 25, 50 and 100 µL/L densities of coconut oil n-caprylic acid respectively. And the change of algal density, cell permeability and antioxidant ability were measured. RESULTS: The greater the concentration of coconut oil n-caprylic acid, the stronger the inhibition on M. aeruginosa. When the concentration was 100 µL/L and processed time was 96 h, the inhibition ratio on M. aeruginosa reached 99%. Compared with the control group, the algal liquid conductivity, nucleic acid content and protein content of experimental groups increased significantly. The SOD activity enhanced with the increasing of coconut oil n-caprylic acid concentration (under 25 µL/L), but when beyond a certain concentration (exceed 25 µL/L), its activity weakened greatly. And the MDA content increased with the increasing of coconut oil n-caprylic acid concentration. CONCLUSION: Coconut oil n-caprylic acid has a significant inhibiting effect on M. aeruginosa. Its mechanism may be largely related to cell membrane permeability change and antioxidant capacity reducing.