Fig. 1.

The viability of Serratia marcescens WW4 and Pseudomonas aeruginosa WW5 in pure or co-cultures. The viability of S. marcescens WW4 (a) or P. aeruginosa WW5 (b) pure culture in LB, M9 or BM medium was counted at 0, 3, 6, 12, 24, 48 and 72 h. The individual viability of co-cultured S. marcescens WW4 and P. aeruginosa WW5 in BM medium is shown in (c). To confirm the effect of phosphate, the viability of P. aeruginosa WW5 in co-culture is shown in (d), when cultured in phosphate-supplied BM medium (BM+1/2P or BM+P) or phosphate-reduced M9 medium (M9 P-reduced), compared with BM or M9 medium. All data show the means of viable cell numbers (CFU mL⁻¹), and the bars represent the standard error.