Occurrence and Distribution of Proteinase of Streptococcus faecalis var. liquefaciens

Shugart, Lee R. (University of Tennessee, Knoxville),and Raymond W. Beck . Occurrence and distribution of proteinase ofStreptococcus faecalis var.liquefaciens . J. Bacteriol.92: 338–341. 1966.—The proteolytic enzyme produced byStreptococcus faecalis var.liquefaciens (ATCC 13398) was shown to be an exoenzyme. The production of the proteinase was followed in growing cultures, and its distribution was compared with that of the intracellular enzymes reduced nicotinamide adenine dinucleotide (NADH2 ) peroxidase and lactate dehydrogenase. The proteinase appeared in the culture medium prior to the stationary phase of growth, whereas the other enzymes could be found only in whole cells. Fractionation of whole cells by sonic treatment and by treatment with lysozyme showed the proteinase to be associated primarily with the cell wall and cell membrane, and NADH2 peroxidase to be associated only with the cytoplasmic fractions.