Table 1.

Parameter values.

Parameter	Symbol	Value	Source
Dimension of neutrophil layer	h N or rN	20–2000 μm	Diegelmann (2003); Fazli et al. (2011); Kragh et al. (2014)
Dimension of biofilm layer	h B or rB	5–1200 μm	Bjarnsholt et al. (2013)
Oxygen concentration at tissue interface	C H	30–160 μM	Spence and Walker (1984)
Oxygen concentration at air interface	C A	190–250 μM	a
First-order oxygen consumption rate for neutrophils	k N	0.001–0.28 s−1	b
First-order oxygen consumption rate for biofilm	k B	0.017–1.7 s−1	c
Diffusion coefficient of oxygen in neutrophil layer	D N	1 × 10−5 cm2 s−1	Stewart (2003)
Diffusion coefficient of oxygen in biofilm layer	D B	1 × 10−5 cm2 s−1	Stewart (2003)

^aAir saturation at elevations from sea level to one mile.

^bRates from Bernstein, Humbert and Hliwa (1985), Green, Hill and Tew (1987) and Kolpen et al. (2010) normalized to 10⁷ neutrophils per ml thenscaled up by a factor of 100 to apply to neutrophil densities of 10⁹ neutrophils per ml (Fazli et al.2011). This calculation result in zero-order rates of 25, 28 and 70 μM s⁻¹, respectively. Salva et al. (1996) suggests the possibility of even higher local neutrophil densities. Ordoñez et al. (2003) reported sputum neutrophil density of 8 × 10⁶ cells per ml. First-order rate coefficients were determined by dividing the zero-order coefficients quoted above by the maximum concentration of oxygen in the system, 250 μM. This concentration corresponds to the dissolved oxygen concentration at equilibrium with air at sea level.

^cUpper and lower values of biofilm zero-order oxygen consumption rate estimated from (μX/Y_xs)(mole/32 g)(10⁶ μmole/mole)(h/3600 s) using ranges of possible specific growth rate (μ, 0.1 to 1 h⁻¹), yield coefficient (Y_xs, 0.5 to 1 g_X per gO₂) and cell density (X, 5 to 25 g_X per liter). This calculation results in zero-order rates that range from 4.3 to 434 μM s⁻¹. First-order rate coefficients were determined as explained in footnote b above.