Minhas T, Greenman J, Schaffer A G
Department of Biological Sciences, University of West England, Bristol, Great Britain.
Microbios. 1993;76(307):105-14.
Porphyromonas gingivalis was grown in continuous culture in brain heart infusion medium with haemin (5 microgm 1(-1) to 10 mg 1(-1)). Growth was haemin-limited up to 400 microgm 1(-1), and steady-state growth could not be obtained in the absence of haemin. It was confirmed that protoporphyrin IX could replace the haemin requirement. The results indicate that P. gingivalis has more than one uptake system for haemin, one of which is high affinity. The effect of haemin on hydrolytic enzyme production revealed a complex picture. Trypsin-like protease activity peaked at 200 microgm 1(-1) with a substantial and highly significant reduction at high (2 and 10 mg 1(-1)) concentrations of haemin. Alkaline phosphatase also peaked around 100 to 400 microgm 1(-1) while N-acetyl-beta-glucosaminidase was not greatly affected except that a greater proportion of enzyme was secreted into the medium at the lowest haemin concentration. In general, haemin-limitation enhanced export of the hydrolytic enzymes to the extracellular vesicle fraction. Protoporphyrin IX at 2 mg 1(-1) caused a highly significant reduction i the production of all three enzymes.
牙龈卟啉单胞菌在添加了血红素（5微克/升至10毫克/升）的脑心浸液培养基中进行连续培养。在血红素浓度达到400微克/升之前，生长受血红素限制，且在没有血红素的情况下无法获得稳态生长。已证实原卟啉IX可以替代对血红素的需求。结果表明，牙龈卟啉单胞菌对血红素有不止一种摄取系统，其中之一是高亲和力系统。血红素对水解酶产生的影响呈现出复杂的情况。类胰蛋白酶活性在200微克/升时达到峰值，在高浓度（2毫克/升和10毫克/升）血红素时大幅且极显著降低。碱性磷酸酶也在100至400微克/升左右达到峰值，而N - 乙酰 - β - 氨基葡萄糖苷酶受影响不大，只是在最低血红素浓度下有更大比例的酶分泌到培养基中。总体而言，血红素限制增强了水解酶向细胞外囊泡部分的输出。2毫克/升的原卟啉IX导致所有三种酶的产量极显著降低。
