L-Amino Acid Oxidases from Mushrooms Show Antibacterial Activity Against the Phytopathogen Ralstonia solanacearum

Author: mycolabadmin
2020-05-19
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Summary

This research discovered antibacterial enzymes from mushrooms that can help protect crops from harmful bacteria. The scientists isolated special proteins called L-amino acid oxidases (LAOs) from two mushroom species and found they could kill or inhibit the growth of bacteria that cause devastating crop diseases. The findings are significant for agriculture and food security. Impacts on everyday life: • Could lead to new natural crop protection products to replace harmful chemical pesticides • May help reduce crop losses and improve food security globally • Demonstrates the untapped potential of mushrooms as sources of useful compounds • Could reduce food costs by preventing crop diseases • Shows promise for developing environmentally-friendly agricultural solutions

Background

Ralstonia solanacearum is a quarantine plant pathogenic bacterium that causes bacterial wilt in over 200 host plants, including economically important crops like potato, tomato, tobacco, banana and ginger. The pathogen results in approximately US$950 million annual losses worldwide, with some countries suffering 30-90% crop losses. There are currently no effective chemical or biological control agents available, making the search for new antibacterial agents particularly important.

Objective

To identify and characterize L-amino acid oxidases (LAOs) from mushroom fruiting bodies with antibacterial activity against R. solanacearum, and evaluate their potential as new biological phytoprotective agents. The study aimed to isolate and biochemically characterize LAOs from Amanita phalloides and Infundibulicybe geotropa, and assess their in vitro and in vivo antibacterial activities.

Results

The isolated LAOs showed broad substrate specificities for hydrophobic and charged amino acids, with highest activity against L-Leu. They demonstrated greater antibacterial activity against Gram-negative versus Gram-positive bacteria. CgLAO and CgmycLAO significantly delayed disease progression in tomato plants, while ApLAO showed no in vivo activity despite strong in vitro effects. Electron microscopy revealed morphological changes in R. solanacearum cells upon LAO treatment. The enzymes showed broad specificity antibacterial activities against multiple phytopathogenic bacteria in vitro screening.

Conclusion

The fungal LAOs isolated from A. phalloides and I. geotropa show great potential as new biological phytoprotective agents. The study demonstrates that fruiting bodies of higher fungi are a valuable source of antimicrobials with unique features. The LAOs from I. geotropa show particular promise as they demonstrate both in vitro and in vivo antibacterial activity against R. solanacearum.

Published in:Frontiers in Microbiology,
Study Type:Laboratory Research,
Source: 10.3389/fmicb.2020.00977