Oct 9, 2019 by News Staff
Scientists have discovered an antibiotic produced by a symbiotic nitrogen-fixing bacterium from a tropical forest in Mexico that may help lead to a ‘plant prebiotic.’
Rhizobium sp. forms nodules on bean plant roots, resulting in a more robust plant (right) than on the left. Image credit: Dmitrii Y. Travin.
The bacterium that produces phazolicin is an unidentified species of Rhizobium. It was isolated in a tropical forest in Los Tuxtlas, Mexico, from the roots of wild beans called Phaseolus vulgaris.
Like other Rhizobium species, this bacterium forms nodules on bean plant roots and provides plants with nitrogen, making them grow more robustly than others. Unlike other species of Rhizobium, it also defends plants from harmful bacteria sensitive to phazolicin.
The phenomenon could eventually be exploited in beans, peas, chickpeas, lentils, peanuts, soybeans and other legumes.
“We hope to show the bacterium can be used as a ‘plant probiotic’ because phazolicin will prevent other, potentially harmful bacteria from growing in the root system of agriculturally important plants,” said Professor Konstantin Severinov, from the Waksman Institute of Microbiology and Rutgers University-New Brunswick.
Using computer and bioinformatic analysis, Professor Severinov and colleagues predicted the existence of phazolicin and then confirmed its existence in the lab.
They revealed the atomic structure of the antibiotic and showed it is bound to and targets the ribosome, a protein production factory in bacterial cells.
They also found they can modify and control sensitivity, or susceptibility, to the antibiotic by introducing mutations in ribosomes.
“Antibiotic resistance is a huge problem in both medicine and agriculture, and continuing searches for new antibiotics are very important as they may provide leads for future anti-bacterial agents,” Professor Severinov said.
The findings appear in the journal Nature Communications.
Dmitrii Y. Travin et al. 2019. Structure of ribosome-bound azole-modified peptide phazolicin rationalizes its species-specific mode of bacterial translation inhibition. Nature Communications 10, article number: 4563; doi: 10.1038/s41467-019-12589-5
Thanks to: http://www.sci-news.com