FIG. 3.

Bacterial growth on mucus of Montastraea faveolata. Isolates of Serratia marcescens, P. mandapamensis 33C12, and E. coli DH5α were grown on mucus from a nonhost coral, M. faveolata. Bacteria were seeded into seawater containing 60 mg ml⁻¹ (wt/vol) total mucus (closed triangles) or high-molecular-mass (>15 kDa; open squares) or low-molecular-mass (<15 kDa; open diamonds) fractions. Growth was monitored by dilution plating. (Insets) The extent to which the bacteria hydrolyzed substrates in mucus was examined using a BCA assay as described in Materials and Methods. White bars indicate accumulation of reducing group equivalents in the low-molecular-mass fraction of mucus; gray bars indicate accumulation of reducing group equivalents in the high-molecular-mass fraction of mucus; and black bars indicate accumulation of reducing group equivalents in total mucus. (A) Growth of S. marcescens PDL100. (B) Growth of S. marcescens EL31. (C) Growth of S. marcescens MG1. (D) Growth of P. mandapamensis 33C12. (E) Growth of E. coli DH5α. Graphs show the results from a representative experiment; error bars indicate standard errors from three parallel independent cultures.