Project description:Streptomyces clavuligerus is an industrially important producer of clavulanic acid (CA), a β-lactamase inhibitor which is used together with amoxicillin in one of the most widely prescribed antibacterial medicines, the co-amoxiclav. In a mid-eighties ATCC vial of S. clavuligerus ATCC 27064 culture, we have found a new genotype, which was apparently lost from the subsequent ATCC collection stocks, and has remained obscure to the scientific community. Most importantly, this genotype harbors teleocidin (lyngbyatoxin) biosynthetic genes, which are located on an enigmatic 138 kb chromosomal region and support accumulation of significant amounts of these highly toxic, tumor-promoting secondary metabolites in cultures of S. clavuligerus. While this genomic region is completely absent from all published sequences for S. clavuligerus ATCC strain, at least one of the industrial strains for commercial production of CA, originating from ATCC 27064, retained the genetic potential for production of teleocidins. The origin of teleocidin biosynthetic cluster can now be traced back to early S. clavuligerus stocks at the ATCC. Our work provides a genome sequence and a deposited monoisolate of this genotype. Given the scale of industrial use of S. clavuligerus world-wide and toxicity of teleocidins, we also discuss the environmental and safety implications and provide a method of abolishing teleocidin production without affecting productivity of CA. KEY POINTS: • Early stocks of S. clavuligerus ATCC 27064 produce toxic teleocidins • Teleocidin biosynthetic genes were found within a distinct S. clavuligerus genotype • The genotype has been passed on to some industrial clavulanic acid producer strains.
Project description:To increase production of the important pharmaceutical compounds, both mutagenesis approaches and rational engineering have been extensively applied. Mutagenesis approaches are most popular in industry, but their effects have not yet been studied very well. Here, we used microarrays to compare the transcriptomes of the S. clavuligerus wild type (ATCC 27064) strain and the DS48802 clavulanic acid high-producer strain, which has been obtained by classical strain improvement (mutagenesis).
Project description:To increase production of the important pharmaceutical compounds, both mutagenesis approaches and rational engineering have been extensively applied. Mutagenesis approaches are most popular in industry, but their effects have not yet been studied very well. Here, we used microarrays to compare the transcriptomes of the S. clavuligerus wild type (ATCC 27064) strain and the DS48802 clavulanic acid high-producer strain, which has been obtained by classical strain improvement (mutagenesis). Streptomyces clavuligerus strains were grown in shake flasks. RNA was extracted after 70h and hybridized to microarrays.
Project description:The objective is to analyze the differential expression between the wild strain and a pSCL4- S. clavuligerus mutant Experiment type Expression profiling by array
Project description:Clavulanic acid (CA) is a powerful inhibitor of the beta-lactamases, enzymes produced by bacteria resistants to penicillin and cefalosporin. This molecule is produced industrially by strains of Streptomyces clavuligerus in complex media which carbon and nitrogen resources are supplied by inexpensive compounds still providing high productivity. The genetic production improvement using physical and chemical mutagenic agents is an important strategy in programs of industrial production development of bioactive metabolites. However, parental strains are susceptible to loss of their original productivity due genetic instability phenomenona. In this work, some S. clavuligerus mutant strains obtained by treatment with UV light and with MMS are compared with the wild type (Streptomyces clavuligerus ATCC 27064). The results indicated that the random mutations originated some strains with different phenotypes, most divergent demonstrated by the mutants strains named AC116, MMS 150 and MMS 54, that exhibited lack of pigmentation in their mature spores. Also, the strain MMS 150 presented a larger production of CA when cultivated in semi-synthetics media. Using other media, the wild type strain obtained a larger CA production. Besides, using the modifed complex media the MMS 150 strain showed changes in its lipolitic activity and a larger production of CA. The studies also allowed finding the best conditions for a lipase activity exhibited by wild type S. clavuligerus and the MMS150 mutant.
Project description:Clavulanic acid is a clinically-important secondary metabolite used in treatment of infectious diseases. We aimed to decipher complex regulatory mechanisms acting in clavulanic acid biosynthesis through the analysis of transcriptome- and proteome-wide alterations in an industrial clavulanic acid overproducer Streptomyces clavuligerus, namely DEPA and its wild-type counterpart NRRL3585.