Screening of Producing Polyphenol Oxidase Strains from the Fermentation Process of Liupao Tea and Purification of Polyphenol Oxidase

In this study, 42 strains of microorganisms were isolated by traditional culture methods from the fermentation process of Liupao tea. The agar plate screening and liquid culture second round of screening was used to select microorganisms from 42 strains of microorganisms that could produce PPO. Then, the activity of PPO produced by microorganisms was measured. Salting out and dialysis were used to purify the microbial fermentation broth with the highest enzyme activity. The SDS-PAGE and Native-PAGE method was applied to determine the molecular weight and type of the PPO. The results identified 10 screened strains with PPO activity and No.16 (Pantoea vagans) with the highest activity. The enzyme activity of Pantoea vagans was 37 U/mL. The enzyme-producing activity of bacteria was generally higher than the fungus. The molecular weight of PPO between 16~48 kDa, the result showed that the enzyme was laccase. This study supplies a basis for exploring the relationship between Liupao tea quality and microorganisms. It can also provide data for the research and development of functional Liubao tea.