Fig. 3

RNA stable isotope probing (RNA SIP) results for a Illium 55 °C, 9 h experiment; b Burke 55 °C, 9 h experiment; c Hafa Adai (Alba) 55 °C, 9 h experiment; d Hafa Adai (Voodoo Crater-2) 55 °C, 9 h experiment; e Hafa Adai (Voodoo Crater-2) 80 °C, 9 h experiment; and f Hafa Adai (Voodoo Crater-2) 80 °C, 18 h experiment. The left column shows density comparison of ¹²C (lighter line) and ¹³C (darker line) RNA-SIP experiments by ratio of 16S rRNA gene reverse transcription-quantitative PCR (RT-qPCR) count over maximum count of all density fractions for all incubations. For 80 °C incubations, the ¹³C-bicarbonate 9 h incubation was also compared to 18 h ¹²C-bicarbonate incubation, since no 9 h ¹²C-bicarbonate incubation was conducted. The middle column shows gene presence in peak ¹³C-RNA-SIP fraction metatranscriptomes. Solid outlined circles indicate complete pathway was observed and dashed outlines indicate partial pathway observed. Single-gene observations have no black outline. The right column shows dominant (>1%) integrated microbial genome (IMG) taxonomic assignment of genes with 30% or greater BLAST identities from RNA-SIP metatranscriptome