University of Alberta

Queen's University at Kingston

Smithkline Beecham Corporation

Other

Glaxo Group Limited

Susan E Jensen

Saul Wolfe

Donald Westlake

Barry Barton

Ashish S Paradkar

Kwamena A Aidoo

John Patrick Griffin

Cecilia Anders

Roy Henry Mosher

Ashish Sudhakar Paradkar

Jian Yang

Richard Nigel Coleman

Perrin Hudson Beatty

Alison Michelle Griffin

Prem Dutt Kharbanda

Jalpa P Tewari

Annie Wong

New processes for improving the manufacture of clavams e.g. clavulanic acid. Novel DNA sequences and new microorganisms capable of producing increased amounts of clavulanic acid are also disclosed.

Process for improving the manufacture of clavams e.g. clavulanic acid

Novel bacterial genes, microorganisms and processes for improving the manufacture of 5R clavams, eg. clavulanic acid.

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Isolated DNA comprising one or more genes specific for 5S clavam biosynthesis, vectors comprising such DNA and streptomyces hosts capable of improved clavulanic acid production

strain ATCC 202127 capable of producing a peptide antibiotic against fungi, and specifically Leptosphaeria spp. is disclosed. Further, mutants of said strain capable of producing the peptide are also disclosed. In addition, a method of controlling a fungal disease of a crop is disclosed. The method comprises applying an amount of the strain or mutants thereof to at least one of a medium for growing the crop, seeds of the crop prior to planting, and plants of the crop. The strain can also inhibit the growth of bacteria such as Micrococcus spp., Streptomyces spp. or Escherichia spp. The fungi which the strain or mutants thereof capable of producing the peptide are effective against include in addition to Leptosphaeria spp., the fungus selected from Sclerotinia spp., Rhizotonia spp., Pythium spp., Fusarium spp., Alternaria spp., Aspergillus spp., Sporobolomyces spp., Trichoderma spp., Penicillium spp. or Marasmius spp.

Paenibacillus polymyxa strain ATCC 202127 for biocontrol of bacteria and fungi

DNA sequences are provided which encode the enzymes required for clavulanic acid synthesis. A process is provided for producing clavulanic acid in a transformant of a non-clavulanate-producing host.

DNA sequence encoding enzymes of clavulanic acid biosynthesis

A process for producing unnatural penicillins and cephalosporin derivatives thereof in which peptide analogs of ACV in which the L-.alpha.-aminodipyl moiety is replaced by L-S-carboxymethyl cysteine or other obvious substituents, are reacted with cyclase, epimerase, ring expansion and hydroxylase enzymes isolated from a cell free extract of a prokaryotic organism such as S. clavuligerus. The product depends upon the presence or absence of co-factors such as ferrous ion, .alpha.-ketoglutarate, and ascorbate. In an alternative embodiment, a penicillin analog having the formula: ##STR1## may be reduced with L-cysteine to produce an analog of isopenicillin N which may be reacted with the enzyme reagent to produce the desired penicillin or cephalosporin.

Biosynthesis of unnatural cephalosporins

Enzymes extracted from a prokaryotic .beta.-lactam producing microorganism are immobilized on a support for producing desacetoxycephalosporin and analogs thereof from L-.alpha.-aminoadipyl-L-cysteinyl-D-valine and analogs thereof. The enzymes are an epimerase, a cyclase and a ring expansion enzyme extracted preferably from S. clavuligerus, S. cattleya or S. lipmanii. The support is preferably a diethylaminoethyl ion exchange resin.

Enzyme immobilization for producing cephalosporin antibiotics

A process is disclosed for converting a peptide precursor of the ACV type, in which the valine moiety may be replaced by any readily available amino acid, to an unnatural cephalosporin of the type ##STR1## where R.sub.1 is H, lower alkyl or functionalized carboxylic group and R.sub.2 is H or lower alkyl, in which the precursor is reacted with cyclase, epimerase and a ring expansion enzyme isolated from a cell-free extract of a prokaryotic organism such as Streptomyces clavuligerus. The three enzymes may be immobilized on a suitable support medium and the conversion may be carried out in a continuous mode.

Cyclase, epimerase and a ring expansion enzyme are isolated separately from a cell free extract of a prokaryotic beta-lactam producing organism to provide three separate and stable enzyme reagents for commercial production of cephalosporins from peptide precursors. Isolation is carried out by using ammonium sulfate, gel filtration and ion exchange chromatography. The enzymes may be immobilized on a suitable support and the production of cephalosporins may be carried out continuously.

Stable epimerase reagent, cyclase reagent and ring expansion reagent for

The enzymes, cyclase, epimerase and a ring expansion enzyme, are isolated separately from a cell-free extract of a prokaryotic beta-lactam producing organism. The isolated enzymes are used to produce unnatural cephalosporins from polypeptide precursors. Isolation is carried out by adding ammonium sulfate to 40% saturation to the cell-free extract to precipitate contaminating proteins, adding ammonium sulfate to 70% saturation to the resultant supernatant to precipitate the enzymes, suspending the precipitated enzymes in a buffer, separating epimerase from the suspension by gel filtration, and separating cyclase and the ring expansion enzyme from each other by ion exchange chromatography.

Growing community of inventors

Edmonton, Canada

Susan E Jensen