Isolation and Antioxidative Activities of Algal Endophytes

Abstract:

The study compared the antioxidative activities of typical algal endophytes in Ulva lactuca L. and Undaria pinnatifida Suringar from Beibu Gulf in Guangxi and screened out the better ones. Among the first 12 strains with stronger antioxidative activities, 9 potent strains were screened out for the further study. Results indicated that the scavenging activities of algal endophytes on DPPH, hydroxyl radical and superoxide anions increased with concentrations. There was a significant difference in the antioxidative activity between Ulva lactuca L. and Undaria pinnatifida Suringar (P<0.05). The semi-inhibition concentrations (IC50) of endophytic bacteria from Ulva lactuca L. and Undaria pinnatifida Suringar for DPPH, hydroxyl radical and superoxide anions were significantly higher than those of endophytic fungi, indicating that the antioxidative activities of endophytic bacteria were significantly lower than those of endophytic fungi. SZ-5 strain from Ulva lactuca L. had the strongest potency to scavenge DPPH, hydroxyl and superoxide anions, and the IC_{50 was （0.59±0.06）, （1.30±0.36） mg/mL and (1.14±0.35) mg/mL, respectively. SZ-5 was identified as Aureobasidium spp.}