Microbial reduction and resistance to selenium: Mechanisms, applications and prospects

Area of Science:

• Environmental Microbiology
• Biogeochemistry
• Biotechnology

Background:

• Selenium is a vital trace element for all life forms.
• Microbial selenium transformations, especially dissimilatory reduction, are gaining research interest for bioremediation.
• Understanding selenium-reducing pathways is crucial for environmental and health applications.

Purpose of the Study:

• To review microbial selenium-reducing pathways under diverse environmental conditions (anaerobic and aerobic).
• To explore the phylogenetic relationships of selenium-reducing enzymes.
• To discuss the broader implications of selenium transformations in ecosystems and potential applications.

Main Methods:

• Literature review of studies on microbial selenium reduction pathways and enzymes.
• Analysis of phylogenetic clustering of selenium-reducing enzymes.
• Discussion of selenium transformation links to biogeochemical cycles and ecological roles.

Main Results:

• Multiple selenium reduction pathways exist, varying with conditions and bacterial strains.
• A single selenium reductase can possess multiple metabolic functions.
• Se(IV) reduction efficiency does not directly correlate with Se(IV) resistance in bacteria.

Conclusions:

• Selenium transformations are intricately linked to other element cycles and microbial ecology.
• Se-reducing bacteria play significant roles in soil, plant, and digestive systems.
• Functional genes in selenium transformation offer potential as environmental biomarkers and for bioremediation/fortification strategies.