Characterization of Bacterial Community Contaminating Floor of A Hot and Dry Sauna

ABSTRACT

The purpose of this study was to examine profile of bacteria contaminated in a dry sauna. Bacteria sampled from the floor of the dry sauna (75~80degrees C) were separated and identified by using a thermal gradient gel electrophoresis (TGGE) technique, and were cultivated using a defined medium at 50degrees C. Bacteria grown in the defined medium were identified based on 16S-rDNA sequence homology. The band number of DNA separated by TGGE was 15, indicating the species diversity of bacteria contaminating the dry sauna. Seven species of bacteria were successfully cultured on agar plate medium at 50degrees C, which represented a combination of thermophilic and thermoduric bacteria contaminating the dry sauna. The highest limit temperature for growth of the bacterial isolates was generally 50degrees C when cultivated in a defined medium, but was raised to 60degrees C when cultivated in a complex medium. Consequently, the bacteria grown at 50~60degrees C are thermoduric or thermophilic, but others may not be.