Adaptive responses of Rhodococcus aetherivorans L13 to oligotrophy: genome and transcriptomic analysis

Area of Science:

• Microbiology
• Environmental Science
• Genomics

Background:

• Actinobacteria, including Rhodococcus aetherivorans, are widespread and possess adaptations for nutrient-limited environments.
• Understanding bacterial responses to oligotrophic conditions is crucial for various ecological and biotechnological applications.
• Rhodococcus aetherivorans L13 exhibits unique growth capabilities in nutrient-deficient settings, necessitating investigation into its adaptive mechanisms.

Purpose of the Study:

• To elucidate the genetic and metabolic strategies employed by Rhodococcus aetherivorans L13 for adaptation to oligotrophic conditions.
• To compare gene expression profiles between cells grown in oligotrophic environments and those grown with a glucose source.

Main Methods:

• Genome sequencing and assembly of Rhodococcus aetherivorans L13.
• RNA-sequencing (RNA-Seq) to analyze gene transcript abundance under different growth conditions.
• Comparative analysis of gene expression data to identify differentially regulated genes.

Main Results:

• The Rhodococcus aetherivorans L13 genome consists of a chromosome and six plasmids.
• RNA-Seq identified significant dysregulation (44% of detected genes) in response to oligotrophic conditions.
• Key metabolic shifts include activation of air component utilization, aldehyde/alcohol metabolism, C2 metabolism, glyoxylate shunt, and TCA bypass, alongside downregulation of CO2-releasing enzymes.

Conclusions:

• Rhodococcus aetherivorans L13 employs a carbon-conservative metabolic strategy for oligotrophic adaptation.
• Adaptation involves reduced metabolic activity, enhanced C2 and ketoacid metabolism, and utilization of alternative carbon sources like air components.
• The study provides a genetic basis for understanding bacterial resilience in nutrient-scarce environments.