One lot of tea drinks were found deteriorated,with pH decrease,gas production,swell can,visible deposition and discoloration.Over 104 CFU/mL bacteria were detected in 3 samples.Four main bacteria were isolated and identified by 16S rDNA sequence blast as Pseudomonas sp.,Enterobacter sp.,Bacillus sp.,and Brevibacillus sp.A few fungi were also detected in all 3 samples with amount of 101~102 CFU/mL.They were identified primarily as Alternaria spp.,Cladosporium spp.,Aspergillus spp.,and Penicillium spp.In this case,although fungi were not the main putrefactive organisms,but its unique flora were just the same as those of air,indicating that air was probably the pollutant source.And the bacterial flora also supported this deduction.In practice,the pollution was solved by replaced the air filter to confirm the conclusion.