Iuodval'kite D Iu, Glemzha A A, Gal'vidis I Iu
Mikrobiologiia. 1982 Nov-Dec;51(6):919-25.
The effect of growth conditions on urease synthesis was studied with Staphylococcus saprophyticus L-1 isolated from natural sources. Urease biosynthesis was recorded in the absence of urea in the complete medium and in the conditions of nitrogen deficiency; the highest level of the enzyme biosynthesis was found when the culture was grown in the absence of amine nitrogen in the medium. Ammonium ions were a reversible inhibitor of urease and, at a high concentration (30 g of (NH4)2SO4 per litre of the medium), partly repressed its biosynthesis. The rate of growth was low when the cells were cultivated in flasks in a medium containing urea (20 g per litre of the medium). The growth was not inhibited when the cells were cultivated in 20-litre fermenters at the same concentration of urea, but with automatic pH regulation. The alkaline medium rather than urea contained in it appeared to be the principal factor inhibiting growth of the culture.
利用从天然来源分离得到的腐生葡萄球菌L-1研究了生长条件对脲酶合成的影响。在完全培养基中不存在尿素以及氮缺乏的条件下记录到了脲酶的生物合成；当培养物在培养基中不存在胺氮的情况下生长时，发现酶生物合成水平最高。铵离子是脲酶的可逆抑制剂，在高浓度（每升培养基30克硫酸铵）时会部分抑制其生物合成。当细胞在含有尿素（每升培养基20克）的烧瓶中培养时，生长速率较低。当细胞在相同尿素浓度但具有自动pH调节功能的20升发酵罐中培养时，生长并未受到抑制。似乎是碱性培养基而非其中所含的尿素是抑制培养物生长的主要因素。
