Acremonium chrysogenum strain

Diez B, Mellado E, Fouces R, Rodriguez M, Barredo JL. Recombinant Acremonium chrysogenum strains for the industrial production of cephalosporin. Microbiologia 12(3) 359-370, 1996. 

The ancestral strain of Acremonium chrysogenum (at that time called Cephalosporium acremonium) was isolated on the Sardinian coast in 1945 following an observation that the local sewage outlet into the sea cleared at a quite remarkable rate. Advances were slow because the activity was associated with a number of different types of compound. Cephalosporin C was first isolated in 1952, but it was a further decade before clinically usefiil semisynthetic cephalosporins became available. 

Cephalosporin C (Figure 7.37) is produced commercially by fermentation using cultures of a high-yielding strain of Acremonium chrysogenum (formerly Cephalosporium acremonium). Initial studies of the antibiotic compounds synthesized by C. acremonium identified penicillin N (originally called cephalosporin N) as the major component, with small amounts of cephalosporin C. In contrast to the penicillins, cephalosporin C was stable under acidic conditions and also was not attacked by penicillinase ((5-lactamase). Antibacterial activity was rather low, however, and the antibiotic was poorly absorbed after oral administration. However, the structure offered considerable scope for side-chain modifications, more so than with the penicillins since it has two side-chains, and this has led to a wide variety of cephalosporin drugs, many of which are currently in clinical use. As with the penicillins, removal of the amide... 

These approaches, developments, and states in industrial strain improvement and pathway characterization will be illustrated for some of the best characterized organisms, namely the two fungal species mainly employed in industrial [3-lactam antibiotic production, the penicillin producing Peni-cillium chrysogenum, and the cephalosporin C producer Acremonium chrysogenum. 

On the one hand, the implication of RNAi may supply an explanation for observations made in the course of strain improvement programs of Penicillium chrys-ogenum and Acremonium chrysogenum, according to which antibiotic productivity can decrease drastically upon amplification of genes involved in antiobiotic biosynthesis. 

P. A. Fawcett, B. Loder, M. J. Duncan, T. J. Biesley, and E.P. Abraham, Formation and properties of protoplasts from antibiotic-producing strains of Penicillium chrysogenum and Cephalo-sporium acremonium, J.gen. Microbiol. 79, 293 (1973). 

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