DESCRIPTION OF 2 NEW THERMOPHILIC DESULFOTOMACULUM SPP, DESULFOTOMACULUM-PUTEI SP-NOV, FROM A DEEP TERRESTRIAL SUBSURFACE, AND DESULFOTOMACULUM-LUCIAE SP-NOV, FROM A HOT-SPRING

Six strains of thermophilic, endospore-forming, sulfate-reducing bacte ria were enriched and isolated from 2.7 km below the earth's surface i n the Taylorsville Triassic Basin in Virginia, The cells of these stra ins were motile rods that were 1 to 1.1 mu m in diameter and 2 to 5 mu m long. The cells grew by oxidizing H-2, formate, methanol (weakly), lactate (incompletely, to acetate and CO2), or pyruvate (incompletely) while reducing sulfate to sulfide; acetate did not serve as a catabol ic substrate, Thiosulfate or sulfite could replace sulfate as an elect ron acceptor, The results of a phylogenetic analysis of the 16S rRNA g ene indicated that these strains belong to the genus Desulfotomaculum, but are distinct from previously described Desulfotomaculum species, Thus, we propose a new species, Desulfotomaculum putei, for them, with strain TH-11 (= SMCC W459) as the type strain, The results of our phy logenetic analysis also indicated that strain SLTT, which was isolated from a hot spring and has been described previously (T. M. Karnauchow , S. F. Koval, and K. F. Jarrell, Syst. Appl. Microbiol, 15:296-310, 1 992), is also a member of the genus Desulfotomaculum and is distinct f rom other species in this genus, We therefore propose the new species Desulfotomaculum luciae for this organism; strain SLT (= SMCC W644) is the type strain of D. luciae.