TABLE 3.

Equations for calculating parameters relevant to microbial cellulose utilization based on continuous culture data

ParameterUnitsSymbolEquationa
Growth rate1/hμ$$mathtex$$\({\mu}{=}\mathit{D}\)$$mathtex$$
Hydrolysis rateg of cellulose/liter/hrS$$mathtex$$\(\mathit{r}_{\mathit{S}}{=}\mathit{D}(\mathit{S}_{0}{-}\mathit{S})\)$$mathtex$$
Cell yieldg of cells produced/g of cellulose consumedYX/S$$mathtex$$\(\mathit{Y}_{\mathit{X}/\mathit{S}}{=}\frac{\mathit{X}}{\mathit{S}_{0}{-}\mathit{S}}\)$$mathtex$$
Cellulase yieldg of cellulase produced/g of cellulose consumedYE/S$$mathtex$$\(\mathit{Y}_{\mathit{E}/\mathit{S}}{=}\frac{\mathit{E}}{\mathit{S}_{0}{-}\mathit{S}}\)$$mathtex$$
Cell-specific hydrolysis rateg of cellulose/g of cells/hrSX$$mathtex$$\(\mathit{r}_{\mathit{S}}^{\mathit{X}}{=}\mathit{D}{\,}\frac{(\mathit{S}_{0}{-}\mathit{S})}{\mathit{X}}{=}\mathit{D}{\,}\frac{\mathit{S}_{0}{-}\mathit{S}}{\mathit{Y}_{\mathit{X}/\mathit{S}}(\mathit{S}_{0}{-}\mathit{S})}{=}\frac{\mathit{D}}{\mathit{Y}_{\mathit{X}/\mathit{S}}}\)$$mathtex$$
Cellulase-specific hydrolysis rateg of cellulose/g of cellulase/hrSE$$mathtex$$\(\mathit{r}_{\mathit{S}}^{\mathit{E}}{=}\mathit{D}{\,}\frac{(\mathit{S}_{0}{-}\mathit{S})}{\mathit{E}}{=}\mathit{D}{\,}\frac{\mathit{S}_{0}{-}\mathit{S}}{\mathit{Y}_{\mathit{E}/\mathit{S}}(\mathit{S}_{0}{-}\mathit{S})}{=}\frac{\mathit{D}}{\mathit{Y}_{\mathit{E}/\mathit{S}}}\)$$mathtex$$
  • a Symbol definitions: D, dilution rate (h−1); S0, feed cellulose concentration (g/liter); S, fermentor substrate concentration (g/liter); X, cell concentration (g/liter); E, cellulase concentration (g/liter).