Antivirus and Prebiotic Properties of Seaweed-oligosaccharide-lysates Derived from Agarase AS-II

Abstract

The seaweed-oligosaccharide-lysates (SwOSLys) Gra-C108, Mon-C108, Gra-AS-II, or Mon-AS-II are seaweed polysaccharide extracts (SwPSExts) Gra (Gracilaria sp.) or Mon (Monostroma nitidum), as digested by either crude MAEF108-agarases or Agarase AS-II produced from marine bacteria Aeromonas salmonicida MAEF108. Different concentrations of Gra, Mon, Gra-C108, Mon-C108, Gra-AS-II, or Mon-AS-II were cultured with different cell densities of BHK-21 kidney cells, in which the SwPSExts or SwOSLys samples showed no cytotoxicity, and the cell viability was higher than 78%. The six seaweed samples displayed an ability to decrease the effects caused by Japanese encephalitis virus (JEV, Beijing-1 strain) infection. The six seaweed samples were tested as a carbon source for bifidobacteria growth to evaluate the prebiotic potentials. Viable bacteria counts of Bifidobacterium ( B.) pseudolongum subsp. pseudolongum BCRC 14673 could increase more than 3 log CFU/ml in 24 h incubation, when Gra-C108 is utilized. Mon and its agarase lysates can be used by bifidobacteria as a carbon source. B. adolescentis BCRC 14608 and B. pseudolongum subsp. pseudolongum BCRC 14673 could utilize the six seaweed samples to lower pH. B. longum BCRC 11847 displayed an increased pH-lowering ability when utilizing the Gracilaria sp. (red algae) than Mon. nitidum (green algae) as based samples.