Elicitation of Pseudomonas aeruginosa with live and dead microbial cells enhances phenazine production

摘要

Biotic elicitation mimics the inter-species interactions in the natural habitat by introducing live or dead cells into the culture of an antibiotic producer resulting in complex metabolic and physiological responses. We report the exploitation of the interspecies interaction to enhance phenazine production by Pseudomonas aeruginosa. Live and heat killed cells of three microorganisms have been tested as elicitors: gram negative E. coli; gram positive Bacillus subtilis and the eukaryotic organism Saccharomyces cerevisiae. For the elicitation with live cells, phenazine production increased significantly by 2.4, 1.8 and 1.9 fold in cultures elicited with E. coli, Bacillus subtilis and Saccharomyces cerevisiae respectively, compared to the pure cultures of P. aeruginosa. Moreover, this study showed that the heat killed cells of the elicitors had the same elicitation effects as the live cells. In these cultures, production of phenazine was increased by 1.43, 2.1 and 3.19 fold in cultures elicited with heat killed cells of E. coli, Bacillus subtilis and Saccharomyces cerevisiae respectively. Such inter- species interactions may form the basis of new strategies in the search for novel antibiotics and other bioactive compounds. They can also be used to increase the productivity of existing processes for antibiotics as it was found in this work.