Time-Course Transcriptome of <i>Parageobacillus thermoglucosidasius</i> DSM 6285 Grown in the Presence of Carbon Monoxide and Air

• Main Authors: Habibu Aliyu, Teresa Mohr, Don Cowan, Pieter de Maayer, Anke Neumann
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: International Journal of Molecular Sciences
• Subjects: Carbon monoxide; hydrogen; Parageobacillus thermoglucosidasius¸ time-course; transcriptomics; and Water-Gas-Shift reaction
• Online Access: https://www.mdpi.com/1422-0067/21/11/3870
• ISSN: 1661-6596; 1422-0067

<i>Parageobacillus thermoglucosidasius </i>is a metabolically versatile, facultatively anaerobic thermophile belonging to the family <i>Bacillaceae</i>. Previous studies have shown that this bacterium harbours co-localised genes coding for a carbon monoxide (CO) dehydrogenase (CODH) and Ni-Fe hydrogenase (Phc) complex and oxidises CO and produces hydrogen (H₂) gas via the water-gas shift (WGS) reaction. To elucidate the genetic events culminating in the WGS reaction, <i>P. thermoglucosidasius</i> DSM 6285 was cultivated under an initial gas atmosphere of 50% CO and 50% air and total RNA was extracted at ~8 (aerobic phase), 20 (anaerobic phase), 27 and 44 (early and late hydrogenogenic phases) hours post inoculation. The rRNA-depleted fraction was sequenced using Illumina NextSeq, v2.5, 1x75bp chemistry. Differential expression revealed that at 8 vs 20, 20 vs 27 and 27 vs 44 hours post inoculation, 2190, 2118 and 231 transcripts were differentially (FDR < 0.05) expressed. Cluster analysis revealed 26 distinct gene expression trajectories across the four time points. Of these, two similar clusters, showing overexpression at 20 relative to 8 hours and depletion at 27 and 44 hours, harboured the CODH and Phc transcripts, suggesting possible regulation by O_2.The transition between aerobic respiration and anaerobic growth was marked by initial metabolic deterioration, as reflected by up-regulation of transcripts linked to sporulation and down-regulation of transcripts linked to flagellar assembly and metabolism. However, the transcriptome and growth profiles revealed the reversal of this trend during the hydrogenogenic phase.