Thiobacillus thiooxidans

The primary biological function of these bacteria is the oxidation of reduced sulfur compounds, such as elemental sulfur, sulfides, and thiosulfates, into sulfuric acid.

During their metabolism, these bacteria generate the energy required for carbon dioxide fixation while releasing strong acids as metabolic byproducts.

Intense activity of these microorganisms leads to localized acidification of the soil solution surrounding plant roots.

In agronomic practice, the presence of these bacteria is considered a biochemical factor that influences the availability of mineral nutrition and the soil pH environment.

The development of Thiobacillus thiooxidans populations depends directly on the availability of a substrate for oxidation, primarily finely divided elemental sulfur.

Aerobic conditions are essential for active reproduction, as the process of sulfur oxidation requires a constant supply of oxygen.

The optimal pH range for most strains of these bacteria is quite low, allowing them to dominate in acidic environments.

Favorable factors include moderate soil moisture and temperatures ranging from 20 to 30 degrees Celsius.

The presence of organic matter in the soil may slow down their activity, whereas the application of mineral sulfur-containing fertilizers triggers a rapid increase in their population density.

The main risk is the rapid decrease in soil pH, which leads to the degradation of soil structure and the leaching of essential nutrients.

Excessive accumulation of sulfuric acid in the rhizosphere can result in root system toxicity for sensitive crops.

Acidification promotes the release of heavy metals from the soil adsorption complex, making them more available for uptake by plants.

Under high acidity, the development of beneficial microflora, including nitrogen-fixing bacteria, is inhibited, reducing natural soil fertility.

The indirect harm manifests as reduced overall yield and decreased plant resilience to environmental stress factors.

The primary control method is soil liming, which helps to neutralize the excess acid produced during bacterial sulfur oxidation.

Fractional application of sulfur-containing fertilizers is recommended to avoid sudden spikes in sulfur-oxidizing bacterial populations.

Crop rotation and the use of organic amendments play a crucial role in maintaining a stable acid-base balance.

Drip irrigation helps control salt concentrations in the root zone, preventing localized hyper-acidification.

• Regular soil pH monitoring
• Optimized dosage of sulfur fertilizers
• Application of dolomite flour
• Aeration of compacted soils