title: Exploiting adaptive laboratory evolution of Streptomyces clavuligerus for antibiotic discovery and overproduction.
abstract: Adaptation is normally viewed as the enemy of the antibiotic discovery and development process because adaptation among pathogens to antibiotic exposure leads to resistance. We present a method here that, in contrast, exploits the power of adaptation among antibiotic producers to accelerate the discovery of antibiotics. A competition-based adaptive laboratory evolution scheme is presented whereby an antibiotic-producing microorganism is competed against a target pathogen and serially passed over time until the producer evolves the ability to synthesize a chemical entity that inhibits growth of the pathogen. When multiple Streptomyces clavuligerus replicates were adaptively evolved against methicillin-resistant Staphylococcus aureus N315 in this manner, a strain emerged that acquired the ability to constitutively produce holomycin. In contrast, no holomycin could be detected from the unevolved wild-type strain. Moreover, genome re-sequencing revealed that the evolved strain had lost pSCL4, a large 1.8 Mbp plasmid, and acquired several single nucleotide polymorphisms in genes that have been shown to affect secondary metabolite biosynthesis. These results demonstrate that competition-based adaptive laboratory evolution can constitute a platform to create mutants that overproduce known antibiotics and possibly to discover new compounds as well.
authors.affiliation: Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Pep
authors.initials: P
authors.lastname: Charusanti
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Fong
authors.forename: Harish
authors.initials: H
authors.lastname: Nagarajan
authors.forename: Alban R
authors.initials: AR
authors.lastname: Pereira
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Li
authors.forename: Elisa A
authors.initials: EA
authors.lastname: Abate
authors.forename: Yongxuan
authors.initials: Y
authors.lastname: Su
authors.forename: William H
authors.initials: WH
authors.lastname: Gerwick
authors.forename: Bernhard O
authors.initials: BO
authors.lastname: Palsson
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005075:Biological Evolution; D024881:Drug Resistance, Bacterial; D016680:Genome, Bacterial; D007769:Lactams / Q000737:chemistry / Q000378:metabolism*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D007769:Lactams; C015265:holomycin