Quantitaitve OM43 Transcriptome

The OM43 clade of Betaproteobacteria are abundant coastal methylotrophs with a range of carbon utilizing capabilities. However, their underlying transcriptional and metabolic responses to shifting conditions or different carbon substrates remains poorly understood. We examined the transcriptional dynamics of OM43 isolate NB0046 to varying inorganic nutrient, vitamin, and carbon substrate regimes over several growth phases to (1) develop a quantitative model of their mRNA content (2) identify transcriptional markers of physiological activity, nutritional state, and carbon and energy utilization, and (3) identify pathways involved in methanol or naturally occurring Dissolved Organic Matter (DOM) metabolism. Quantitative transcriptomics, achieved through addition of internal RNA standards, allowed for analyses on a transcripts cell-1 scale. The genome-wide inventory of cellular transcript abundances produced here provides insight into a streamlined marine bacterium’s regulation of carbon metabolism and energy flow, providing benchmarks for evaluating the activity of OM43 populations in situ.