Microbiological analysis and antibacterial effects of the indigenous fermented Puer tea

Microbiological analysis was done on samples from an indigenously fermented tea - Puer. Microbial counting and identification revealed that Aspergillus niger was the dominating microorganism during the fermentation. Antimicrobial activity of fermentation samples showed inhibitory effect on several food borne bacteria, including spore forming bacteria Bacillus cereus, Bacillus subtilis, Clostridium perfringens and Clostridium sporogenes. The antimicrobial activity increased with the course of the fermentation. This implied that certain metabolites of Aspergillus niger growing on tea leaves had the feature of inhibiting certain food borne spoilage and pathogen microorganisms.