@article{mbs:/content/journal/micro/10.1099/00221287-91-1-1, author = "Bascomb, Shoshana and Banks, G. T. and Skarstedt, M. T. and Fleming, A. and Bettelheim, K. A. and Connors, T. A.", title = "The Properties and Large-scale Production of l-Asparaginase from Citrobacter", journal= "Microbiology", year = "1975", volume = "91", number = "1", pages = "1-16", doi = "https://doi.org/10.1099/00221287-91-1-1", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-91-1-1", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Summary: An intracellular l-asparaginase with antitumour activity was purified from a strain of Citrobacter. The optimum conditions for enzyme production by fermentation on scales up to 2700 l were investigated. Highest enzyme yield was obtained in corn-steep liquor medium (9·2%, w/v) at 37 °C. Oxygen limitation was not necessary for high enzyme yield. A total recovery of 4·3% from nucleic-acid-free extract and a 180-fold increase in specific activity were obtained after purification. The specific activity of the purified preparation was 45 i.u./mg protein. The enzyme hydrolysed d-asparagine and l-glutamine at 7 and 5%, respectively, of its activity toward l-asparagine, but l-glutaminase activity could be demonstrated only at substrate concentrations above 5 mm. The Km values for l-asparagine and d-asparagine were 2·6 × 10−5 and 1·4 × 10−4 respectively. The anti-lymphoma activity of the enzyme was demonstrated with Gardner lymphosarcoma and was found only slightly less potent that Crasnitin, the most active asparaginase so far tested in this system.", }