MYCOLab Ai Logo - gold and army green

Biodegradation of Microcystins by Aquatic Bacteria Klebsiella spp. Isolated from Lake Kasumigaura

Summary

Scientists discovered three bacteria from a Japanese lake that can effectively break down microcystins, toxic substances produced by harmful algal blooms. These bacteria work well at warm temperatures and alkaline conditions typical of contaminated lakes during summer. The research shows these bacteria contain a special gene that helps them degrade different types of microcystins, offering a promising biological solution for cleaning contaminated water without harmful side effects.

Background

Microcystins are highly toxic cyanotoxins produced during harmful cyanobacterial blooms that pose significant threats to plant, animal, and human health. Physical and chemical water treatments have proven ineffective for MC removal. Biodegradation by MC-degrading bacteria offers a promising, safe, and cost-effective alternative approach.

Objective

This study aimed to isolate new MC-degrading bacteria from Lake Kasumigaura and investigate how temperature, pH, and MC variants affect biodegradation. Additionally, the researchers examined the presence of the MC-degrading gene (mlrA) in isolated strains.

Results

Three Klebsiella isolates (TA13, TA14, TA19) were identified, with TA13 showing the highest MC-degradative activity (87.3% after 10 h). All three strains effectively degraded MC-RR, MC-YR, and MC-LR, with optimal degradation at 40°C. The strains degraded MCs across pH 6.0-10.0, with highest degradation at neutral pH 7.0. The mlrA gene was detected in all three strains, marking the first report of this gene in Klebsiella species.

Conclusion

The three isolated Klebsiella strains exhibit superior MC degradation at higher temperatures and broader pH ranges compared to previously reported MC-degrading bacteria. These strains can effectively degrade multiple MC variants under both neutral and alkaline conditions, making them promising candidates for bioremediation in natural lake waters, particularly as global temperatures rise.
  • Published in:Toxins (Basel),
  • Study Type:Laboratory Research Study,
  • Source: PMID: 40711157, PMCID: PMC12298343
Scroll to Top