Assessment of radiotropic behavior in isolates of Aspergillus niger, Aspergillus calidoustus, and Paecilomyces variotii.

Four filamentous fungi, including two Aspergillus species and two Paecilomyces variotii isolates, showed no measurable radiotropism after 7 days near a 137 Cs gamma source.

• Why it matters: Understanding radiotropism in fungi could reveal mechanisms of radiation adaptation and potential bioremediation applications, but inconsistent methods have hindered progress.
• What they did: Researchers assessed growth rate and direction in four fungal isolates placed at equal distances from a 137 Cs source, measuring responses over a 7-day period.
• The result: No significant differences in growth rate or direction were observed, suggesting these fungi do not exhibit radiotropism under the tested conditions, highlighting the need for further parameter variation.