Minor Actinides Can Replace Essential Lanthanides in Bacterial Life.

Area of Science:

• Biochemistry
• Microbiology
• Radiochemistry

Background:

• Certain f-block elements, lanthanides (4f), are biologically relevant.
• Methylotrophic bacteria incorporate lanthanides into methanol dehydrogenase, a key metabolic enzyme.

Purpose of the Study:

• Investigate if actinides (5f), radioactive elements, can replace lanthanides in bacterial metabolism.
• Determine the viability of actinides in lanthanide-dependent bacterial pathways.

Main Methods:

• Growth studies using Methylacidiphilum fumariolicum SolV and Methylobacterium extorquens AM1 ΔmxaF mutant.
• In vivo and in vitro analyses of bacterial metabolic activity.

Main Results:

• Americium and curium support bacterial growth in the absence of lanthanides.
• Strain SolV preferentially utilizes actinides over late lanthanides when mixed.

Conclusions:

• Methylotrophic bacteria can utilize actinides in place of lanthanides for one-carbon metabolism.
• Actinide utilization depends on appropriate ionic size and a +III oxidation state.