Crow V L, Thomas T D
J Bacteriol. 1982 Jun;150(3):1024-32. doi: 10.1128/jb.150.3.1024-1032.1982.
Streptococcus lactis metabolizes arginine via the arginine deiminase pathway producing ornithine, ammonia, carbon dioxide, and ATP. In the four strains of S. lactis examined, the specific activities of arginine deiminase and ornithine transcarbamylase were 5- to 10-fold higher in galactose-grown cells compared with glucose- or lactose-grown cells. The addition of arginine increased the specific activities of these two enzymes with all growth sugars. The specific activity of the third enzyme involved in arginine metabolism (carbamate kinase) was not altered by the composition of the growth medium. In continuous cultures arginine deiminase was not induced, and arginine was not metabolized, until glucose limitation occurred. In batch cultures the metabolism of glucose and arginine was sequential, whereas galactose and arginine were metabolized concurrently, and the energy derived from arginine metabolism was efficiently coupled to growth. No arginine deiminase activity was detected in the nine Streptococcus cremoris strains examined, thus accounting for their inability to metabolize arginine. All nine strains of S. cremoris had specific activities of carbamate kinase similar to those found in S. lactis, but only five S. cremoris strains had ornithine transcarbamylase activity.
乳酸链球菌通过精氨酸脱亚胺酶途径代谢精氨酸，产生鸟氨酸、氨、二氧化碳和三磷酸腺苷（ATP）。在所检测的四株乳酸链球菌中，与在葡萄糖或乳糖培养基中生长的细胞相比，在半乳糖培养基中生长的细胞中精氨酸脱亚胺酶和鸟氨酸转氨甲酰酶的比活性高5至10倍。添加精氨酸可提高这两种酶在所有生长糖类中的比活性。参与精氨酸代谢的第三种酶（氨基甲酸激酶）的比活性不受生长培养基成分的影响。在连续培养中，直到出现葡萄糖限制，精氨酸脱亚胺酶才被诱导，精氨酸也才开始代谢。在分批培养中，葡萄糖和精氨酸的代谢是顺序进行的，而半乳糖和精氨酸是同时代谢的，并且精氨酸代谢产生的能量有效地与生长相偶联。在所检测的九株乳脂链球菌中未检测到精氨酸脱亚胺酶活性，因此这解释了它们无法代谢精氨酸的原因。所有九株乳脂链球菌的氨基甲酸激酶比活性与乳酸链球菌中的相似，但只有五株乳脂链球菌具有鸟氨酸转氨甲酰酶活性。
