SECRETION KINETICS OF ENDO-N-ACETYL-BETA-D-GLUCOSAMINIDASE DURING VEGETATIVE GROWTH OF MYXOCOCCUS-XANTHUS

It was recently demonstrated that endo-N-acetyl-beta-D-glucosaminidase s (ENGase) acting on N-glycosylproteins are produced by myxobacteria. In this study, it was shown that the secretion of ENGase during vegeta tive growth of Myxococcus xanthus was cell-density-dependent. The acti vity produced per cell increased up to 6 x 10(8) cells/ml and stabiliz ed thereafter (maximum level). Two of the developmental mutants used i n this study (bsgA and csgA) were locked for ENGase secretion into the maximum level regardless of cell density. To explain the pattern of E NGase secretion, we postulated the presence of a molecule that induces the enzyme until it reaches a proper concentration threshold. Althoug h the chemical structure of this cell density signal was not determine d during this study, its occurrence during vegetative growth of M. xan thus was strongly suggested by the results.