Fig. 1.

Photos of the sulfur-turf (white microbial mat) thriving in the hot spring stream and RT-PCR detection of transcripts of genes related to reduced sulfur compound oxidation, respiration, and carbon fixation. The white arrow shows the discharge point of the spring. Hot spring water flows downward from the top to the bottom in this figure. dhsU1 and dhsU2, sulfide dehydrogenase; sqrX and sqrF, sulfide-quinone reductase; sorA, sulfite dehydrogenase; soxX, soxY, soxZ, soxA and soxB, sox complex; rhd1, rhd2 and rhd3, thiosulfate sulfurtransferase; ccoN, cbb-3 type cytochrome c oxidase; aclA, ATP citrate lyase; fumA, fumarate hydratase; forA, 2-oxoglutarate ferredoxin oxidoreductase; rpoZ, RNA polymerase; M, DNA marker.