A halophilic thermophilic bacterium isolated from a coastal hot spring in

A heterotrophic, moderately thermophilic bacterial strain, designated strain T501, was isolated from a hot spring on the coast of Lutao, Taiwan. This bacterial strain was a strictly aerobic, Gram-negative rod, normally 0. 6 4 7 pm in diameter and 4-10 pm in length, and motility was achieved by one to several lateral flagella. Its minimum and maximum growth temperatures were approximately 30 and 60 "C, respectively, with an optimal temperature at about 50 "C. The G + C ratio of its DNA was 38.1 mol%. Strain T501 tolerated a pH range from 6 to 9. It was halophilic, growing optimally in about 2 % (w/v) salt, and Na+ was indispensable unless Mg2+ or Ca2+ were available. The addition of either cation to Na+-sufficient media significantly enhanced growth. Halophilic heterotrophic bacteria capable of aerobic growth over a temperature range of 4&55 "C have not been reported previously