• Korean Journal of Microbiology
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• v.53 no.2
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• pp.83-96
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• 2017

A constructed sea stream in Yeongdo, Busan, Republic of Korea is mostly static due to the lifted stream bed and tidal characters, and receives domestic wastewater nearby, causing a consistent odor production and water quality degradation. Bioaugmentation of a microbial consortium was proposed as an effective and economical restoration technology to restore the polluted stream. The microbial consortium activated on site was augmented on a periodic basis (7~10 days) into the most polluted site (Site 2) which was chosen considering the pollution level and tidal movement. Physicochemical parameters of water qualities were monitored including pH, temperature, DO, ORP, SS, COD, T-N, and T-P. COD and microbial community analyses of the sediments were also performed. A significant reduction in SS, COD, T-N, and COD (sediment) at Site 2 occurred showing their removal rates 51%, 58% and 27% and 35%, respectively, in 13 months while T-P increased by 47%. In most of the test sites, population densities of sulfate reducing bacterial (SRB) groups (Desulfobacteraceae_uc_s, Desulfobacterales_uc_s, Desulfuromonadaceae_uc_s, Desulfuromonas_g1_uc, and Desulfobacter postgatei) and Anaerolinaeles was observed to generally decrease after the bioaugmentation while those of Gamma-proteobacteria (NOR5-6B_s and NOR5-6A_s), Bacteroidales_uc_s, and Flavobacteriales_uc_s appeared to generally increase. Aerobic microbial communities (Flavobacteriaceae_uc_s) were dominant in St. 4 that showed the highest level of DO and least level of COD. These microbial communities could be used as an indicator organism to monitor the restoration process. The alpha diversity indices (OTUs, Chao1, and Shannon) of microbial communities generally decreased after the augmentation. Fast uniFrac analysis of all the samples of different sites and dates showed that there was a similarity in the microbial community structures regardless of samples as the augmentation advanced in comparison with before- and early bioaugmentation event, indicating occurrence of changing of the indigenous microbial community structures. It was concluded that the bioaugmentation could improve the polluted water quality and simultaneously change the microbial community structures via their niche changes. This in situ remediation technology will contribute to an eco-friendly and economically cleaning up of polluted streams of brine water and freshwater.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.418-429
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• 2021

This paper investigates the antioxidant activity and quality characteristics of yanggaeng containing white ginseng and red ginseng extracts and their enzyme hydrolysates that were produced for the purpose of the study. White and red ginseng extracts were hydrolyzed using Rapidase C80 max, Pyr-flo, and Ultimase MFC. Ginsenoside F2 and compound K (CK) were not detected in white and red ginseng before enzymic reaction but were detected in white and red ginseng hydrolyzed through Rapidase C80 max, Pyr-flo, and Ultimase MFC, and the content of CK was the highest in the second enzymic reaction group of red ginseng. Upon preparing yanggaeng containing white and red ginseng before or after enzymatic hydrolysis, the polyphenol content and antioxidant abilities were analyzed. The yanggaeng containing enzyme-hydrolyzed white ginseng and red ginseng showed greater total polyphenol content, superior DPPH radical scavenging activity, superior ABTS radical scavenging activity, and superior FRAP analysis results compared to the yanggaeng that doesn't contain white or red ginseng. As the enzymic reaction was performed in the added white and red ginseng, the antioxidant activity increased significantly (P<0.05). In brightness(L^*), non-additive yanggaeng (control group) was the highest, red ginseng yanggaeng (RG) showed the highest redness(a^*), and the white ginseng yanggaeng (WG) showed the highest yellowness(b^*). In terms of texture, the yanggaeng containing red ginseng with second hydrolysis (RG-T2) showed significantly high results in hardness, springiness, chewiness, cohesiveness, and gumminess (P<0.05). In conclusion, treating white and red ginseng with Rapidase C80 max, Pyr-flo, and Ultimase MFC is very useful in ginsenoside deglycosylation and will produce CK with excellent biological activity. It can also be seen that yanggaeng containing white and red ginseng hydrolyzed with enzymes significantly increase total polyphenol and antioxidant activity compared to the control group (yanggaeng with no added ginseng). These results will be useful as excellent foundational data for the production of functional yanggaeng in the future.