Table 4.
Activity of P. ruminicola 23 esterases tested on various acetylated substrates
| Substrate | Reaction conditions |
Activity (mmol HAc/μmol protein) at 20 min; 2 h; 20 ha |
||||
|---|---|---|---|---|---|---|
| Substrate (g/liter) | Protein concn (μM), AxeA1; Axe7A; Axe1-6A; Xyl10D-Fae1A | AxeA1 | Axe7A | Axe1-6A | Xyn10D-Fae1A | |
| Glucose-pentaacetate | 0.47 (1.2 mM) | 0.05; 0.05; 0.08; 0.25 | 27; 63; ND | 4; 12; ND | 9; 19; ND | <0.5b |
| Cephalosporin C | 0.68 (1.7 mM) | 0.05; 0.05 | 11; 13; ND | 7; 8; ND | ND | ND |
| N-Acetyl-d-glucosamine | 0.64 (2.9 mM) | 0.33; 0.33 | <0.5b | <0.5b | ND | ND |
| N-Acetyl-neuraminic acid (type IV-S) | 0.60 (1.9 mM) | 0.33; 0.33 | <0.5b | <0.5b | ND | ND |
| Acetylated xanthan | 2.0 | 0.04; 0.37 | ND; 1; 1 | <0.5b | ND | ND |
| Sugar beet pectin (acetylated homogalacturonan) | 4.0 | 0.04; 0.37 | <0.5b | <0.5b | ND | ND |
| Apple MHR (branched pectin) | 4.0 | 0.04; 0.37 | ND; 5; 7 | <0.5b | ND | ND |
| Acetylated xylo-oligosaccharides (DP 2-20; wood) | 4.0 | 0.04; 0.37 | ND; 79; 116 | ND; <0.5; 4 | ND | ND |
| Acetylated xylan (polymer) | 4.0 | 0.04; 0.37 | ND; 26; 29 | <0.5b | ND | ND |
| Acetylated GlcAme-xylo-oligosaccharides (DP 4-12) | 4.0 | 0.04; 0.37 | ND; 125; 125 | ND; <0.5; 3 | ND | ND |
| X2GlcAAc + X2GlcAmeAc (FA-20) | 1.0 | 0.04; 0.37 | ND; 8; 11 | <0.5b | ND | ND |
a
ND, not determined.
b
Amount of acetic acid released below the level of detection (0.5 μM) in 20 h.