Cedar H, Schwartz J H
J Bacteriol. 1968 Dec;96(6):2043-8. doi: 10.1128/jb.96.6.2043-2048.1968.
l-Asparaginase II was synthesized at constant rates by Escherichia coli under anaerobic conditions. The enzyme was produced optimally by bacteria grown between pH 7 and 8 at 37 C. Although some enzyme was formed aerobically, between 100 and 1,000 times more asparaginase II was produced during anaerobic growth in media enriched with high concentrations of a variety of amino acids. Bacteria grown under these conditions should provide a rich starting material for the large-scale production of the enzyme. No single amino acid specifically induced the synthesis of the asparaginase, nor did l-asparagine, even when it was used as the only source of nitrogen. The enzyme was produced at lower rates in the presence of sugars; glucose was the most inhibitory.
在厌氧条件下，大肠杆菌以恒定速率合成L-天冬酰胺酶II。该酶在pH值为7至8、温度为37℃的条件下生长的细菌中产量最佳。虽然在有氧条件下也能形成一些酶，但在富含多种高浓度氨基酸的培养基中进行厌氧生长时，产生的天冬酰胺酶II要多100至1000倍。在这些条件下生长的细菌应为大规模生产该酶提供丰富的起始原料。没有单一氨基酸能特异性诱导天冬酰胺酶的合成，L-天冬酰胺也不能，即使它被用作唯一的氮源。在有糖存在的情况下，该酶的产量较低；葡萄糖的抑制作用最强。
