Enhancement of Polyphenol Content and Antioxidant Activity of Brown Alga Eisenia bicyclis Extract by Microbial Fermentation

Abstract

The objective of this study was to select an effective microbial strain to improve the functional qualities of Eisenia bicyclis water extract by fermentation. For this purpose, several microorganisms isolated from traditional Korean fermented foods were inoculated and cultivated in E. bicyclis water extract. Ultimately, yeast strain YM-1 was selected for further study based on its total phenolic compound (TP) content and antioxidant activity, which were enhanced by microbial fermentation. The extract fermented by YM-1 exhibited a superior TP content and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity compared to extracts fermented by other microbes. The highest TP content and DPPH radical scavenging activity were observed after one day of YM-1 fermentation. Yeast strain YM-1 was identified as Candida utilis based on an analysis of its physiological characteristics. During fermentation of the extract by C. utilis YM-1, no significant difference was observed in the proximate composition, including moisture, crude lipid, crude protein, and crude ash. Fermentation by C. utilis YM-1 resulted in enhanced biological activity, including increases in the TP content and antioxidant activity. Thus, fermentation by C. utilis YM-1 is an attractive strategy for developing value-added food ingredients.

Enhancement of Antioxidant Activity, Total Phenolic and Flavonoid Content of Saccharina japonica by Submerged Fermentation with Aspergillus oryzae

“…2) and the highest phenolic content was found after 5 days of fermentation. These results are consistent with the previous data showing that Lactobacillus fermentation of a Hizikia fusiforme [32] and yeast fermentation of Eisenia bicycilis [30] enhanced the phenolic content. The enhancement of phenolic content might be due to the fact that enzymes released from A. oryzae breakdown the cell wall of seaweed which helps to release out more phenolic compounds in the water.…”

“…Recently, fermentation of seaweed has been attracting much more interest as seaweed contains lots of polysaccharides. Previously, it has been reported that fermentation of seaweed by different lactic acid bacteria enhances the bioactive compound as well as biofunctional activity [27][28][29][30]. However, submerged fermentation of S. japonica by A. oryzae has been merely reported.…”

“…3 & 4). Previous studies have also demonstrated that fermentation process enhances the antioxidant activity [29][30]. Considering this, fermentation technique was applied to improve the antioxidant activity.…”

Synergistic Antibacterial Activity of Ecklonia cava (Phaeophyceae: Laminariales) against Listeria monocytogenes (Bacillales: Listeriaceae)

“…In fact, compounds with antioxidant, antiviral, antifungal, and antimicrobial activities have been detected in brown, red, and green algae (Eom et al, 2011). Ecklonia cava, of the family Laminariaceae, ranges along the eastern coast of Korea and Japan.…”

“…The antibacterial efficacy of marine algae extracts was evaluated by disk diffu sion assay followed by the CLSI (2009), as described in our previous reports (Lee et al, 2014;Eom et al, 2011). In brief, bacterial strains were cultured in BHI at 37°C until an OD at 600 nm of 0.5.…”