Extracellular matrix components required for coculture biofilm structure. (A) Colony morphology of B. subtilis strains lacking genes encoding essential matrix components (epsA-O, bslA, and tasA) in monoculture (top) and in coculture with P. agglomerans (bottom) grown on MSgg for 48 h. (B) Representative P. agglomerans mutants (transposon insertion amsC::kan, P. agglomerans amsC, P. agglomerans amsC complemented with amsC on a plasmid [pBBR1MCS-amsC], amsC plus pBBR1MCS [empty vector control]) grown in monoculture (top) and coculture with B. subtilis (bottom) in a 1:500 B. subtilis-to-P. agglomerans ratio on MSgg for 48 h. Bars, 1 mm.