Article Figures & Data
Figures
- FIG. 1.
Oxygen uptake rates of homogenized Paecilomyces variotii biomass from STBE with various intermediates.
- FIG. 2.
Toluene oxygenase activity with different toluene concentrations. Vmax and Km are the constants from the Michaelis-Menten model. Chisq, chi-square test; NA, not applicable.
- FIG. 3.
Evolution of the toluene EC (•) and CO2 (⋄) production in a 2.5-liter biofilter inoculated with Paecilomyces variotii. Arrows indicate the time of mineral medium additions, and the diagonal line shows the average EC and the average CO2 production.
- FIG. 4.
Evolution of the toluene EC (•) and CO2 (⋄) production in the STBE inoculated with Paecilomyces variotii (TA, start of toluene addition).
- FIG. 5.
Correlation between the average experimental EC measured in different biofiltration systems and the calculated elimination capacity, ECc, obtained through the enzymatic activity values. ○, five different biofiltration experiments (9); ▪, STBE. The line corresponds to EC = ECc.
Tables
- TABLE 1.
Carbon balance for the various intermediates of the toluene metabolic pathways used as growth substrates for Paecilomyces variotii
Carbon source Substrate (mg) Biomass (mg) Biomass yield (mg/mg) CO2 yield (mg/mg) Glucose 30.0 14.4 0.48 0.58 Toluene 6.26 5.2 0.83 1.58 Benzyl alcohol 6.26 3.1 0.50 1.87 Benzaldehyde 6.26 3 0.48 2.10 Benzoate 6.26 2.4 0.38 0.66 Catechol 6.49 3.8 0.59 2.25 m-Cresol 6.05 3 0.50 1.94 p-Cresol 6.05 3.6 0.60 1.84 o-Cresol 6.05 0.2 0.03 0.55 Protocatehuate 8.63 3.9 0.45 1.49 - TABLE 2.
Comparison of the enzymatic activity of Paecilomyces variotii biomass produced in liquid culture and in STBE
Experimental system Oxygenase sp act (nmol O2/min/mg biomass)a Dehydrogenase sp act (nmol NADH/min/mg protein)b Biomass from liquid culture 4.7 ND Cell extract ND 16.2 (NAD+) 4.6 (NADP+) Biomass from STBE 6.3 ND Homogenized 11.9 ND Cell extract ND 36.6 (NAD+) 0.2 (NADP+) - TABLE 3.
Volatile intermediates produced from toluene consumption in biofilters by Paecilomyces variotiib
Time (days) Toluene EC (g/m3 biofilm/h) and REa (%) Recovered intermediate (mg/liter biofilter/h) Carbon recovered as intermediate (%) Yield (%C)c BOH BA p-C BOH BA p-C 7 62 (53) 0.15 0.054 0.054 0.206 0.076 0.076 0.357 11 126 (94) 0.018 0.022 0.05 0.012 0.015 0.034 0.003 13 124 (95) 0.012 0.018 0.02 0.008 0.013 0.014 0.002 - TABLE 4.
Correlation between the experimental EC measured in the biofilter and the calculated EC obtained through the enzymatic activity values
Biofilter level Humidity (%) Biomass concn in each level (mg/g DM) Volumetric enzymatic activity (nmol O2/min/g WM)a Specific enzymatic activity (nmol O2/min/mg biomass) Calculated ECc (g/m3 biofilm/h) Experimental EC (g/m3 biofilm/h)b Inlet 31 15.1 65.6 6.3 83.1 117 Level 2 42 21.6 56.2 4.5 85.3 ND Level 3 51 36.6 56.2 3.1 102.5 262 Level 4 59 39.3 46.9 2.9 102.4 ND Outlet 73 143.4 76.2 1.9 283.7 317 Global 131.4 232
