Morphology of Mycoplasma laidlawii type A. II. Effect of glucose on growth and cellular morphology.

Anderson, D. L. (University of Minnesota, Minneapolis), M. E. Pollock, and L. F. Brower. Morphology of Mycoplasma laidlawii type A. II. Effect of glucose on growth and cellular morphology. J. Bacteriol. 90:1768-1777. 1965.-Cells of Mycoplasma laidlawii A grown in soy peptone-yeast extract (SP-YE) broth reached higher maximal titers than cells grown in SP-YE supplemented with 0.2% glucose, and remained viable longer than glucose-grown cells. Moreover, addition of glucose to SP-YE markedly affected the morphological developmental sequence of the organism. The diameter of glucose-grown cells at 28 to 40 hr was often two to four times that of cells grown without glucose; these large glucose-grown cells deteriorated progressively, and presumably liberated 0.1- to 0.25-mu small bodies. In contrast, pleomorphic 22- to 28-hr cells grown in SP-YE without glucose gave rise to uniform bodies 0.5 to 1.0 mu in diameter; limited numbers of 0.1- to 0.25-mu small bodies were also liberated in nonglucose cultures after 45 to 64 hr. Electron-microscopic counts of 16- to 64-hr cultures agreed well with counts of colony-forming units (CFU) when organisms larger than 0.25 mu were included in the microscopic counts. Small bodies, 0.1 to 0.25 mu in diameter, apparently did not contribute substantially to numbers of CFU. Droplet patterns of cells grown in Arginine Assay Medium and L15 Tissue Culture Medium were cleaner than patterns of cells grown in SP-YE.