Secondary Metabolism and Interspecific Competition Affect Accumulation of Spontaneous Mutants in the GacS-GacA Regulatory System in Pseudomonas protegens
| Autor: | Virginia O. Stockwell, Chunxu Song, Kerry L. McPhail, Joyce E. Loper, Oliver B. Vining, Lucas Dantas Lopes, Teresa A. Kidarsa, Qing Yan, Benjamin Philmus, Jos M. Raaijmakers, Jeff H. Chang, Fernando Dini Andreote, Brenda T. Shaffer |
|---|---|
| Přispěvatelé: | Microbial Ecology (ME) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
medicine.drug_class Microorganism 030106 microbiology Antibiotics Mutant Bacillus subtilis Biology Microbiology 03 medical and health sciences chemistry.chemical_compound Pseudomonas protegens Biosynthesis Bacterial Proteins Phenols Virology Pseudomonas Botany medicine Pyrroles Secondary metabolism Genetics secondary metabolism interspecific competition biology.organism_classification spontaneous mutations QR1-502 030104 developmental biology chemistry international GacS-GacA Mutation Microbial Interactions PSEUDOMONAS Energy Metabolism Research Article Transcription Factors |
| Zdroj: | mBio mBio, Vol 9, Iss 1, p e01845-17 (2018) mBio, 9(1):e01845-17. American Society for Microbiology Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP mBio, Vol 9, Iss 1 (2018) |
| ISSN: | 2150-7511 2161-2129 |
| Popis: | Secondary metabolites are synthesized by many microorganisms and provide a fitness benefit in the presence of competitors and predators. Secondary metabolism also can be costly, as it shunts energy and intermediates from primary metabolism. In Pseudomonas spp., secondary metabolism is controlled by the GacS-GacA global regulatory system. Intriguingly, spontaneous mutations in gacS or gacA (Gac− mutants) are commonly observed in laboratory cultures. Here we investigated the role of secondary metabolism in the accumulation of Gac− mutants in Pseudomonas protegens strain Pf-5. Our results showed that secondary metabolism, specifically biosynthesis of the antimicrobial compound pyoluteorin, contributes significantly to the accumulation of Gac− mutants. Pyoluteorin biosynthesis, which poses a metabolic burden on the producer cells, but not pyoluteorin itself, leads to the accumulation of the spontaneous mutants. Interspecific competition also influenced the accumulation of the Gac− mutants: a reduced proportion of Gac− mutants accumulated when P. protegens Pf-5 was cocultured with Bacillus subtilis than in pure cultures of strain Pf-5. Overall, our study associated a fitness trade-off with secondary metabolism, with metabolic costs versus competitive benefits of production influencing the evolution of P. protegens, assessed by the accumulation of Gac− mutants. IMPORTANCE Many microorganisms produce antibiotics, which contribute to ecologic fitness in natural environments where microbes constantly compete for resources with other organisms. However, biosynthesis of antibiotics is costly due to the metabolic burdens of the antibiotic-producing microorganism. Our results provide an example of the fitness trade-off associated with antibiotic production. Under noncompetitive conditions, antibiotic biosynthesis led to accumulation of spontaneous mutants lacking a master regulator of antibiotic production. However, relatively few of these spontaneous mutants accumulated when a competitor was present. Results from this work provide information on the evolution of antibiotic biosynthesis and provide a framework for their discovery and regulation. |
| Databáze: | OpenAIRE |
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