FIG. 1.
RNase-free culture medium of R. sulfidophilum. The supernatant of R. sulfidophilum DSM 1374T or E. coli JM 109 culture medium was incubated with synthetic tRNA substrate (+ Synthetic tRNA) for 30 min or 90 min at 37°C as described in Materials and Methods. The reaction mixtures were analyzed by 10% denaturing PAGE. − Synthetic tRNA, no addition of the substrate to the reaction mixture; R-culture and E-culture, R. sulfidophilum culture medium and E. coli culture medium, respectively; nt, nucleotides. The cultivation time (17, 16, 27, 42, 65, or 87 h) and the reaction time (30 or 90 min) are indicated. RNase A represents the reaction mixture with RNase A instead of culture supernatant as a positive control.