Tellurite and selenite processing by tellurite resistant marine microbes

Area of Science:

• Environmental Microbiology
• Biotechnology
• Biogeochemistry

Background:

• Microbial transformations of tellurium and selenium are crucial for environmental remediation and green nanoparticle synthesis.
• Previously isolated aerobic marine yeast and bacteria strains exhibit tellurite resistance.
• Understanding microbial metabolism of selenite and tellurite mixtures is essential for process optimization.

Purpose of the Study:

• To explore the capability of marine yeast and bacteria to metabolize selenite and tellurite mixtures.
• To quantify the fate of selenium and tellurium under different conditions.
• To identify volatile metabolic products and assess their toxicity implications.

Main Methods:

• Culturing of marine yeast (Rhodotorula mucilaginosa) and bacteria (Bacillus spp., Virgibacillus halodenitrificans) resistant to tellurite.
• Exposure of microbial cultures to selenite and mixtures of selenite and tellurite.
• Analysis of volatile compound production and precipitation of selenium and tellurium species.

Main Results:

• Selenite metabolism differs from tellurite metabolism in the studied microbes.
• Volatile selenium compound production correlates with selenite resistance but is not predictable from tellurite resistance.
• Tellurite in mixtures inhibits selenium volatilization, increases precipitation of tellurium and selenium, and reduces volatile compound production.

Conclusions:

• Microbial selenium and tellurium metabolism is influenced by the presence of both metalloids.
• Combined selenium and tellurium exposure promotes precipitation and reduces volatile toxic byproducts, making it potentially safer for remediation and nanoparticle synthesis.
• Further research into biochemical mechanisms is needed to fully understand Te and Se fate in microbial processes.