Strains of Aureobasidium pullulans from Extreme Environments: New Potential Biocontrol Agents?

Author: mycolabadmin
11/14/2025
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Summary

Researchers studied yeast strains collected from extreme environments like deserts and cold coastlines to find natural solutions for protecting fruit crops. They found that Aureobasidium pullulans, a black yeast that thrives in harsh conditions, can effectively control brown rot disease on peaches. The strains showed remarkable ability to survive extreme temperatures and pH levels, making them promising candidates for environmentally friendly crop protection that could help agriculture adapt to climate change.

Background

Extremophilic microorganisms represent an underexplored reservoir of microbial diversity with potential agricultural applications. Aureobasidium pullulans, a black yeast, is recognized as a poly-extremotolerant microorganism and potential biocontrol agent against postharvest fungal pathogens. This study investigates strains isolated from extreme environments across multiple continents.

Objective

To characterize 67 A. pullulans strains isolated from extreme environments in Italy, Sweden, Algeria, and France through molecular identification and phylogenetic analysis. To evaluate their extremotolerant behavior under different temperatures and pH conditions, assess enzymatic production, and test their potential as biocontrol agents against Monilinia fructicola.

Results

Molecular analysis identified 67 A. pullulans strains grouped by geographic origin. Strains demonstrated remarkable thermotolerance and pH adaptability, with Groups 2 (Algerian Desert) and 3 (Alto Adige Region) showing highest thermotolerance and biocontrol ability respectively. In vitro inhibition rates exceeded 70% in some strains, while in vivo assays showed near-complete disease suppression. All tested strains produced cellulase and xylanase enzymes but no siderophores.

Conclusion

Extreme environments represent promising sources for biocontrol agents with superior stress tolerance and efficacy against postharvest pathogens. The ecological plasticity of A. pullulans and its adaptation to diverse environmental extremes support its potential as a climate-resilient biocontrol strategy. Further research on mechanisms of action and secondary metabolism is needed for practical agricultural applications.

Published in:Microorganisms,
Study Type:Experimental Study,
Source: 10.3390/microorganisms13112596, PMID: 41304280