The β-lactamase inhibitor, clavulanic acid is frequently used in combination with β-lactam antibiotics to treat a wide spectrum of infectious diseases. Clavulanic acid prevents drug resistance by pathogens against these β-lactam antibiotics by preventing the degradation of the β-lactam ring, thus ensuring eradication of these harmful microorganisms from the host. This systematic review provides...

In Streptomyces coelicolor bldA encodes the principal leucyl tRNA for translation of UUA codons and controls pigmented antibiotic production by the presence of TTA codons in the genes encoding the pathway-specific activators of actinorhodin and undecylprodigiosin biosynthesis. In Streptomyces clavuligerus the gene encoding the pathway-specific activator of both cephamycin C and clavulanic acid ...

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 a...

The (p)ppGpp synthetase gene, relA, of Streptomyces clavuligerus was cloned, sequenced and shown to be located in a genomic region that is highly conserved in other Streptomyces species. relA-disrupted and relA-deleted mutants of S. clavuligerus were constructed, and both were unable to form aerial mycelium or to sporulate, but regained these abilities when complemented with wild-type relA. Nei...

A regulatory gene (ccaR), located within the cephamycin gene cluster of Streptomyces clavuligerus, is linked to a gene (blp) encoding a protein similar to a beta-lactamase-inhibitory protein. Expression of ccaR is required for cephamycin and clavulanic acid biosynthesis in S. clavuligerus. The ccaR-encoded protein resembles the ActII-ORF4, RedD, AfsR, and DnrI regulatory proteins of other Strep...

Carboxyethylarginine synthase genes show complex cross regulation in 1 Streptomyces clavuligerus 2 Thomas Kwong, Kapil Tahlan, Cecilia L. Anders and Susan E. Jensen 3 Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9 Canada 4 5 6

Protoplasts of the wild type Streptomyces clavuligerus NRRL 3585 (ATCC 27064) were formed from spores cultures obtained in the lag, exponential and stationary growth phases by using 0.5% glycine in the culture medium. The protoplasts were obtained by treatment of the cells with lysozyme (EC-3.2.1.17) 40,000 U (1mg/ mL), in an osmotic solution for 90 min at 28oC. The frequency of regenerated pro...

The paper argues for the importance of utterances (as opposed to \sen-tences in context") as basic units in dialogue. The main case study is clar-iication: a characterization is provided within KOS, a recently developed synthesis of situation semantics and dialogue games, of the clariications that can follow up on an utterance. This involves outlining: (a) a theory of understanding for dialogue...

The conditions for optimal formation and regeneration of protoplasts of Streptomyces clavuligerus were established. The optimal temperature for regeneration of protoplasts and for transformation was 26 degrees C in three different regeneration media. The best efficiency of transformation was obtained with 40% polyethylene glycol 1000. The efficiencies of regeneration and transformation increase...

A cluster of genes argCJBDRGH containing most of the arginine biosynthesis genes has been found in Streptomyces clavuligerus after sequencing a 8.3 kb DNA region containing overlapping sequences of two DNA fragments known to contain arginine biosynthesis genes. Subcloning, complementation of E. coli arginine auxotrophic strains and enzymatic assays confirmed the identity of each gene. S1 nuclea...