Missing Iron-Oxidizing Acidophiles Highly Sensitive to Organic Compounds.

Area of Science:

• Microbiology
• Environmental Science
• Biotechnology

Background:

• The genus Acidithiobacillus comprises lithoautotrophic bacteria crucial for acidic mine environments.
• Acidithiobacillus ferrooxidans is a key species utilized in precious metal bioleaching.
• Cultivation of A. ferrooxidans type strain revealed emergent cultures with enhanced growth.

Purpose of the Study:

• To isolate and characterize novel iron-oxidizing acidithiobacilli from enrichment cultures.
• To evaluate the industrial potential of newly isolated strains for bioleaching applications.
• To investigate the genomic features of an isolated strain exhibiting superior growth traits.

Main Methods:

• Enrichment and isolation of bacterial strains using inorganic silica-gel plates.
• Phenotypic characterization, including growth assays on various media and sensitivity to organic compounds.
• Draft genome sequencing of a representative isolate (strain NU-1).

Main Results:

• Isolation of strain NU-1, an iron-oxidizing acidithiobacillus with superior growth in inorganic iron media.
• Strain NU-1 demonstrated distinct characteristics, including inability to form colonies on agarose and sensitivity to glucose.
• Genomic analysis revealed unique catabolic enzymes in NU-1, differentiating it from the A. ferrooxidans type strain.
• Silica-gel plate cultivation proved effective for isolating previously unexamined acidithiobacilli.

Conclusions:

• Inorganic silica-gel plates are a valuable tool for isolating novel iron-oxidizing acidithiobacilli.
• Strain NU-1 represents a distinct iron-oxidizing acidithiobacillus with significant potential for industrial bioleaching.
• Further research into strain NU-1's unique genomic features may uncover new bioleaching mechanisms.