GLUCAN-BINDING PROTEINS OF STREPTOCOCCUS-SOBRINUS B13 GROWN IN HIGH GLUCOSE MEDIA

To improve the yield of an 87-kDa glucan-binding protein (GBP) of Stre ptococcus sobrinus B13 (serogroup d), tripticase-yeast extract (TYE) m edium supplemented with higher (1 and 2%) than the usual amount (0.2%) of glucose was used for growth. The production of this GBP extracellu lary in 1.0 and 2.0% glucose-TYE media was examined and compared with the control (0.2% glucose). Upon analysis using SDS-PAGE, extracellula r culture concentrates of 1.0 and 2.0% glucose-TYE cultures revealed s imilar protein profiles as the control. Higher glucose concentrations did not inhibit the synthesis of the 87-kDa GBP. Cells grown in 1.0 or 2.0% glucose-supplemented media aggregated rapidly compared to those observed in the control cells (0.2% glucose grown). Higher cell yield and higher extracellular protein content were obtainable in both 1.0% and 2% glucose-TYE cultures, thus improving the yield of the 87 kDa GB P.