Influence of tannase from Serratia marcescens strain IMBL5 on enhancing antioxidant properties of green tea

• Published in: Biocatalysis and agricultural biotechnology 2020-08, Vol.27, p.101675, Article 101675
• Main Authors: Thiyonila, Berchmans, Kannan, Mani, Paulin Reneeta, Naveenagandhi, Ramya, Thangaraj, Kayalvizhi, Nagarajan, Krishnan, Muthukalingan
• Format: Article
• Language: English
• Subjects: Bacterial tannase; Dung beetle gut microbes; Gel-filtration chromatography; Green tea catechins; Response surface methodology
• ISSN: 1878-8181; 1878-8181
• DOI: 10.1016/j.bcab.2020.101675

The present study was focused on the isolation and screening of potential tannase producing gut microbes from dung beetle Onthophagus babirussa IMBL, further optimized and characterized for industrial applications. Serratia marcescens strain IMBL5 was found to be the most potent tannase producer out of 36 isolates. The adjusted process parameters for maximum tannase yield were pH 4.5 at 45 °C and 96 h incubation. The tannase production was increased 4.46 fold i.e. 120.13 U/mL, by varying the concentration of media components using Response surface methodology. The molecular weight of purified tannase was resolved at ~40 kDa through SDS-PAGE analysis. Several functional groups including carboxyl, hydroxyl and amide groups were detected in FT-IR analysis whilst the occurrence of epicatechin gallate peaks detected from HPLC chromatogram signifying the tannin degradation. Tannase also potentially induce the antioxidant properties of green tea extract which was determined through in-vitro analysis. There was no hemolytic activity exhibited in hemolysis assay using human red blood cells which corroborated that tannase derived from S. marcescens strain IMBL5 might be a safe and promising agent in food industry. [Display omitted] •Tannase production was optimized through OFAT and CCD approach and acquired 4.46 fold augmented yield.•Purification of tannase was carried out and molecular mass was identified as ̴ 40 kDa.•FT-IR and HPLC results revealed the physico chemical properties of tannase.•Tannase is effective in enhancing the antioxidant properties of green tea.•There was no hemolytic activity exhibited for tannase in hemolysis assay which ensures its biocompatibility.