Transcriptomic Analysis of the Dual Response of Rhodococcus aetherivorans BCP1 to Inorganic Arsenic Oxyanions

Area of Science:

• Microbiology
• Environmental Science
• Biochemistry

Background:

• Rhodococcus species are known for degrading toxic compounds and tolerating heavy metals.
• Rhodococcus aetherivorans BCP1 demonstrates resistance to both arsenite [As(III)] and arsenate [As(V)].
• BCP1 shows differential responses: arsenite is toxic at 5 mM, while arsenate at 30 mM promotes growth.

Purpose of the Study:

• To elucidate the mechanisms behind the arsenic stress response in R. aetherivorans BCP1.
• To compare the transcriptomic profiles of BCP1 cells exposed to arsenite and arsenate.
• To understand the metabolic adaptations of BCP1 to different arsenic oxyanions.

Main Methods:

• Transcriptomic analysis of BCP1 cells exposed to 5 mM As(III) and 30 mM As(V).
• Measurement of reactive oxygen species (ROS)-scavenging enzyme activity.
• Analysis of gene expression related to cellular damage recovery, redox buffers, and metabolic pathways.

Main Results:

• As(III) exposure led to higher ROS-scavenging enzyme activity and downregulation of cell division pathways.
• Both As(III) and As(V) downregulated glycolysis.
• As(V) induced metallophore synthesis, rearranged central metabolism, and promoted alternative ATP synthesis and glucose consumption pathways.

Conclusions:

• R. aetherivorans BCP1 displays significant metabolic plasticity in response to different arsenic oxyanions.
• The distinct transcriptomic responses highlight unique adaptation strategies to arsenite and arsenate stress.
• Findings provide insights into rhodococcal energetic metabolism under arsenic stress, relevant for biotechnological applications.