Characteristics of glucosyltransferase from cultures ofStreptococcus mutans 6715 grown in trypticase soy broth and chemically defined media

Streptococcus mutants 6715 was grown in trypticase soy broth and chemically defined media. When compared by cellular mass, DNA content, acid production, or glucosyltransferase (GTase) production, the growth parameters were nearly identical. The doubling time for the organism grown in either medium was approximately 75 min. The extracellular glucosyltransferase produced byS. mutans 6715 grown in both media was purified from the culture supernatant with nearly total recovery and a degree of purification approximately 74-fold. Apparent proteolytic degradation of the enzyme was prevented by nitriloacetate. The temperature effects showed typical loss of enzymatic activity from 37° to 60°C. When the GTase was heated above 60°C there was partial restoration of activity. Immunological studies were used to establish the relationship between the enzymatically active proteins separated by gel filtration chromatography.