Comparison of biological activities in Sargassum siliquanstrum fermented by isolated lactic acid bacteria

Abstract

Brown alga Sargassum siliquanstrum was fermented by isolated lactic acid bacteria including Weissella sp. SH-1, Lactobacillus sp. SH-1, Leuconostoc sp. SH-1, and Streptococcus sp. SH-1, which could efficiently utilize its biologically active materials. Total polyphenol contents, total flavonoid contents and angiotensin converting enzyme inhibitory activities were measured after confirmation of pH and 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging activities. pH and DPPH radical scavenging activities plateaued after 2 days fermentation for each bacterium. Fermentation without algal debris showed better biological activities than fermentation with debris. Fermentation increased DPPH radical scavenging activities from 3.13% to 16.85% compared with non-fermented condition, with Lactobacillus sp. SH-1 being the most efficient. Weissella sp. SH-1 and Leuconostoc sp. SH-1 increased total polyphenol contents by 18.43% and total flavonoid contents by 5.70%, respectively, compared with non-fermented condition. Fermentation by Lactobacillus sp. SH-1 showed the highest angiotensin converting enzyme inhibitory activity (73.93%). Biological activities of S. siliquanstrum were upgraded by isolated lactic acid bacteria, which might be exploited in the development of functional materials or healthy drink products.