The isolation and identification of microbes from a fermented tea beverage, Haipao, and their interactions during Haipao fermentation

Samples of Haipao from three cities of Taiwan were analyzed for their microbial population. Two species of acetic acid bacteria and three species of yeast were isolated from tea fungus Haipao using appropriate isolation media. The isolated bacteria were identified as Acetobacter aceti and Acetobacter pasteurianus, based on their biochemical properties, and compared with those of the type strains of the genus Acetobacter. The yeasts were Saccharomyces cerevisiae, Zygosaccharomyces bailii, and Brettanomyces bruxellensis according to conventional phenotypic characterization combined with the Yeast Identification Program. The brew broth analyzed by high- performance liquid chromatography (HPLC) was shown to contain glycerol, acetic acid and ethanol. The symbiosis phenomenon between the yeast and Acetobacter was studied. It was found that the autoclaved yeast cells and ethanol produced by yeasts were helpful for Acetobacter to grow or produce acetic acid. The acetic acid produced by Acetobacter could stimulate the yeast to produce ethanol. The ethanol and acetic acid produced by yeasts and Acetobacter might prevent the competition from other micro-organisms.