Biofilm viability increases closer to the anode when the electrode is active. Adjacent CLSM images (20 ×) are both 72 hour side-views of S. oneidensis biofilms from batch experiment detected RG7112 using the Live/Dead (baclight) stain. Circle: G. sulfurreducens, Square: P. aeruginosa, Upright triangle: S. oneidensis, Upsidedown triangle: E. faeciumand Diamond: C. acetobutylicum Development and current generation of pure and co-culture anode biofilms During the pure culture closed circuit experiments the heights of the biofilms
were less than that of the open circuit experiments (Table 1). For example, the biofilm click here height of P. aeruginosa was 30 ± 3 μm for the closed circuit experiment and 42 ± 3 μm for the open circuit experiment, as calculated with COMSTAT. All G- cultures developed an ample coverage of the electrode within the three ay period both in closed and open circuit. For example, the S. oneidensis biofilm formed large towers of 40 μm high and up to ~50 μm in diameter while the G+ species developed smaller microcolonies with the odd tower up to 20 μm high and 10-20 μm
in diameter (during closed circuit). The latter was also reflected in the higher roughness coefficient between the G- and G+ biofilms indicating buy Saracatinib that during batch mode the G+ are flatter and more uniform than the G- (Table 2). During these pure culture batch experiments G+ species delivered low current throughout while the G- produced a much higher current as shown in Table 1. Table 1 Comparison of current generation
and biofilm heights in pure and co-cultures. Imax (mA) Maximum Biofilm thickness (μm, batch)-COMSTAT Continuous Batch Closed circuit anode Open circuit anode Pure culture experiments Geobacter sulfurreducens 1.1 ± 0.06 1.0 ± 0.05 25 ± 6 49 ± 5 Pseudomonas aeruginosa 0.5 ± 0.01 0.9 ± 0.01 30 ± 3 42 ± 3 Shewanella oneidensis 1.3 ± 0.05 1.0 ± 0.15 26 ± 2 41 ± 3 Venetoclax Clostridium acetobutylicum 0.13 ± 0.006 0.1 ± 0.03 14 ± 6 24 ± 6 Enterococcus faecium 0.1 ± 0.05 0.2 ± 0.05 18 ± 3 23 ± 4 Co-cultures with Enterococcus faecium Geobacter sulfurreducens 1.9 ± 0.03 – 50 ± 7 – Pseudomonas aeruginosa 1.8 ± 0.04 – 40 ± 4 – Shewanella oneidensis 2.0 ± 0.06 – 39 ± 7 – Co-cultures with Clostridium acetobutylicum Geobacter sulfurreducens 0.1 ± 0.03 – 7 ± 3 – Pseudomonas aeruginosa 0.3 ± 0.05 – 8 ± 2 – Shewanella oneidensis 0.2 ± 0.06 – 5 ± 1 – Table 2 Roughness coefficients of biofilms determine by COMSTAT. Roughness Coefficient -Batch Roughness Coefficient -continuous Closed circuit anode Open circuit anode Pure culture experiments Geobacter sulfurreducens 1.8 ± 0.3 1.0 ± 0.4 1.8 ± 0.2 Pseudomonas aeruginosa 1.8 ± 0.5 1.1 ± 0.2 1.9 ± 0.1 Shewanella oneidensis 1.7 ± 0.2 0.9 ± 0.3 1.9 ± 0.3 Clostridium acetobutylicum 1.5 ± 0.3 1.2 ± 0.3 1.7 ± 0.2 Enterococcus faecium 1.4 ± 0.2 1.2 ± 0.2 1.9 ± 0.