Alginate Oligosaccharide is an oligosaccharide derived from the degradation of alginate. It is composed of β-D-mannuronic acid, α-L-guluronic acid or a hybrid of the two. It has a wide range of biological activities, such as promoting plants Growth, alleviating plant abiotic stress, anti-tumor, antibacterial and other effects, have broad prospects in the fields of green agriculture, medicine and health care. Chen Li et al. studied the inhibitory effect of Alginate Oligosaccharide on three common aquatic pathogens, which provided a theoretical basis for studying the application of marine oligosaccharides in feed.
Three common bacteria, Aeromonas hydrophila, Candida albicans and Vibrio an-guillarum, were used in the experiment. The slant strains were inoculated into a triangular flask containing 100mL liquid medium and cultured at 37℃, 170r/min shaking for 12h as seed solution. Take 5 numbers of 250mL Erlenmeyer flasks, add 60mL of liquid culture medium in turn, and then add Alginate Oligosaccharide respectively, so that the mass concentration of Alginate Oligosaccharide in each flask is 0, 2, 4, 6, 8 g/L, and sterilize. The seed solution was inoculated into 5 Erlenmeyer flasks at a volume fraction of 10%, the concentration of the bacterial solution was adjusted to 106-107 cells/mL, and the bacterial solution in each Erlenmeyer flask was transferred into 12 test tubes, each with 5 mL. Incubate with shaking at 37°C and 170 r/min. Take out 1 test tube at 0, 2, 3.5, 5.5, 7.5, 9.5, 12, 15, 17, 19, 21 and 23 h, mark the time, and put it in the refrigerator Store at 4°C. After all incubation is completed, use a blank medium as a control to measure the optical density at 600nm.
The test results show that Alginate Oligosaccharide has strong antibacterial activity against Aeromonas hydrophila and Candida albicans, and the antibacterial activity increases with the increase of oligosaccharide concentration (see Figures 1 and 3). Alginate Oligosaccharide has almost no antibacterial activity against Vibrio anguillarum in the early period of the exponential phase, but it shows strong antibacterial activity in the latter part of the exponential phase, and the antibacterial activity increases as the concentration of oligosaccharides increases (see Figure 2).