Aims

The control of Xanthomonas citri subsp. citri (X. citri), causal agent of citrus canker, relies heavily in integrated agricultural practices involving the use of copper-based chemicals. Considering the need for alternatives to control this disease and the potential of fungi from extreme regions as producers of bioactive metabolites, we isolated and identified a bioactive compound from Penicillium sp. CRM 1540 isolated from Antarctica marine sediment.

Methods and Results

The compound potential as an antibacterial agent against X. citri was assessed through in vitro and greenhouse experiments. Molecular taxonomy indicates this fungus is a possible new species of Penicillium. The results revealed 90% inhibition at 25 µg mL-1in vitro and a decrease in symptoms emergency for the in vivo experiment in Citrus sinensis (L.) Osbeck leaves. The number of lesions per cm² for the treatment with the isolated compound was 75.31% smaller and significantly different (p <0.05) from the untreated control. The structure of the active agent was identified as penicillic acid based on detailed spectroscopic analysis.

Conclusion

Penicillic acid can be an alternative against citrus canker.

Significance and Impact of Study

Research on extremophile microorganisms can lead to molecules with biotechnological potential and alternatives to current agriculture practices.