Studies on nutritional and oxygen requirements for production of L-asparaginase by Enterobacter aerogenes.
The carbon and nitrogen sources most suitable for L-asparaginase production by Enterobacter aerogenes were selected and their concentrations optimized in shake-flask cultures. Sodium citrate (1.0%) and diammonium hydrogen phosphate (0.16%) proved to be the best sources of carbon and nitrogen, respectively. Nitrogen catabolite repression of enzyme formation was absent in this bacterium. Cultivation in a reactor showed that the dissolved oxygen level is the limiting factor for L-asparaginase production by E. aerogenes. Glucose was found to be a repressor of enzyme synthesis. Asparagine was absent intracellularly when the L-asparaginase level was high. An increase in the extracellular alanine level when the dissolved oxygen remained low indicated a shift from aerobic to fermentative metabolism.
Mukherjee
J
J
Institut für Technische Chemie der Universität Hannover, Germany. mukherjee@mbox.iftc.uni-hannover.de
Majumdar
S
S
Scheper
T
T
D000332:Aerobiosis; D000409:Alanine / Q000378:metabolism; D001215:Asparaginase / Q000096:biosynthesis*; D002851:Chromatography, High Pressure Liquid; D002951:Citrates / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004754:Enterobacter / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D010101:Oxygen Consumption; D010710:Phosphates / Q000378:metabolism; D000077559:Sodium Citrate; D013997:Time Factors
D002951:Citrates; D003470:Culture Media; D010710:Phosphates; C024788:ammonium phosphate; D000077559:Sodium Citrate; D001215:Asparaginase; D005947:Glucose; D000409:Alanine