Jim Newkirk

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The superiority of d-methionine over l-methionine for stimulation of cephalosporin C synthesis in a crude medium was confirmed. The optimal level of dl-methionine was 0.5%. Methionine stimulates growth slightly but this is not thought to be the cause of the marked stimulation of antibiotic synthesis. Of a large number of sulfur compounds tested, only(More)
Demain, A. L. (Merck Sharp & Dohme Research Laboratories, Rahway, N.J.), Joanne F. Newkirk, and D. Hendlin. Effect of methionine, norleucine, and lysine derivatives on cephalosporin C formation in chemically defined media. J. Bacteriol. 85: 339-344. 1963.-Chemically defined media were developed for production of cephalosporin C by Cephalosporium sp. In such(More)
Case-based reasoning (CBR) is an arti cial intelligence methodology that uses speci c encapsulated prior experiences as a basis for reasoning about similar new situations. CBR systems rely on various \knowledge containers," such as the casebase of prior experiences and similarity criteria for comparing situations and retrieving the most relevant cases.(More)
The apparent stimulation of cephalosporin C biosynthesis by sodium thiosulfate is due to a nonbiological conversion of cephalosporin C to a new derivative, cephalosporin C(x). The new compound is more active than cephalosporin C against the assay organism, Escherichia coli W-208. Cephalosporin C(x) retains the properties of ultraviolet absorption and(More)
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