MYCOLab Ai Logo - gold and army green

The Importance of Humic Acids in Shaping the Resistance of Soil Microorganisms and the Tolerance of Zea mays to Excess Cadmium in Soil

Summary

This research explores how humic acids, which are natural organic substances found in soil, can help protect plants and soil bacteria from cadmium, a toxic heavy metal. When cadmium contaminated soil, the application of humic acid preparation called Humus Active promoted the growth of specialized bacteria that can tolerate and break down cadmium. As a result, corn plants grew better and maize biomass increased significantly when the soil was treated with the humic preparation, suggesting this is a practical solution for farming on contaminated land.

Background

Cadmium contamination poses a severe threat to soil environments and plant health through its toxic effects on bacteria essential for soil fertility. Humic substances have been identified as natural agents capable of reducing heavy metal bioavailability in soils. Understanding the interaction between humic acids and soil microbiota under cadmium stress is crucial for developing effective soil remediation strategies.

Objective

To evaluate the effect of Humus Active preparation on the structure, diversity, and functional potential of soil bacteria under cadmium contamination during Zea mays cultivation. The study aimed to determine bacterial taxonomic structure using 16S rRNA sequencing and assess metabolic functions related to metal stress response.

Results

Cadmium caused 92% reduction in Zea mays biomass and 52% decrease in organotrophic bacteria abundance. Humus Active application, particularly at HA4 dose, substantially mitigated cadmium phytotoxicity and stimulated growth of culturable actinobacteria. The bacterial community was dominated by chemoheterotrophs and nitrogen cycle bacteria from tolerant genera including Bacillus, Nocardioides, and Arthrobacter.

Conclusion

Humic acids promote development of stress-resistant bacterial communities with high bioremediating potential, thereby improving plant condition under cadmium contamination. The synergistic interaction between humic acids and cadmium-tolerant microorganisms represents a promising approach for biological remediation of heavy metal-contaminated soils. Appropriately selected humic acid doses provide dual chemical and biological functions in reducing cadmium mobility.
  • Published in:International Journal of Molecular Sciences,
  • Study Type:Experimental Study,
  • Source: PMID: 41465599, PMCID: PMC12733556, DOI: 10.3390/ijms262412175
Scroll to Top