FIG 1.

(A) Predation behavior of Myxococcus xanthus against Gram-positive species Micrococcus luteus and Bacillus subtilis and Gram-negative species Escherichia coli and Agrobacterium tumefaciens. M. xanthus was spotted next to prey bacteria on a CF minimal agar plate, incubated for 2 days, and documented with a stereo microscope. Scale bar, 5 mm. (B) Bacteriolytic activity of M. xanthus protein fractions. Cell suspensions of prey bacteria M. luteus, B. subtilis, E. coli, and A. tumefaciens adjusted to an OD₆₀₀ of 0.08 were spotted on agar plates. Dried spots were overlaid with 2 µl of a sample of intact M. xanthus cells (OD₆₀₀, 0.1), soluble proteins (sol), membrane proteins (mem), or secreted proteins (sec) at a protein concentration as indicated. Agar plates were incubated at 30°C overnight and visually screened for bacteriolytic activity. Results represent three biological replicates. Scale bar, 8 mm.