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Production Of L-asparaginase By Pseudomonas Ovalis.
Published 1974 · Chemistry, Medicine, Biology
Summary The enzyme L-asparaginase has been proved lately to have an inhibitory effect on human iymphosarcoma. Screening of microbial cultures, isolated from Egyptian soils, yielded a bacterium with high potentiality for L-asparaginase production. The organism was isolated on gelatin plates from samples, taken from slaughter house soils, and identified as Pseudomonas ovalis. The enzyme was assayed in intact cells by direct nesslerization of ammonia, liberated in the reaction. L-asparagine and L-aspartic and L-glutamic acids serve as inducers for the enzyme. The enzyme is produced optimum at pH 7.5 and repressed significantly by complex nitrogen sources and certain amino-acids. No activity could be detected in the presence of ammonium phosphate. The highest yield of the enzyme was obtained when the organism was grown aerobically in a medium containing L-glutamic acid and yeast extract, buffered at pH 7.5. Further characterization of the enzyme is reported.