TY - JOUR

T1 - Upgrading the Nutritional Value of PKC Using a Bacillus subtilis Derived Monocomponent β-Mannanase

AU - Gomez-Osorio, Luis Miguel

AU - Nielsen, Janni Ulnits

AU - Martens, Helle Jakobe

AU - Wimmer, Reinhard

N1 - Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/1/1

Y1 - 2022/1/1

N2 - Palm kernel cake (PKC) is an abundant side stream that can only be added to non-ruminant feed in small concentrations due to its content of antinutritional factors, mainly galactomannan, which cannot be digested by non-ruminants. β-mannanases can be added to partially hydrolyze galactomannan to form mannose oligosaccharides, which are known to be prebiotic. We here investigate the action of a β-mannanase from B. subtilis on PKC by colorimetry, NMR and fluorescence microscopy. The amount of mannan oligosaccharides in solution was significantly increased by the β-mannanase and their degree of polymerization (DP) was significantly reduced. There was a dose-response behavior in that larger β-mannanase concentrations increased the amount of soluble mannose oligosaccharides while reducing their average DP. Using confocal immunofluorescence microscopy, solubilization of galactomannan in PKC was clearly visualized. Images show a clear disruption of the cellulose and galactomannan structures of the PKC cell walls. We thus show in this study that using commercial dosages of β-mannanase on PKC can lead to formation of prebiotic compounds. Thus, this study suggests that utilization of PKC in poultry feed formulation might be increased by addition of a β-mannanase and would improve the return on investment.

AB - Palm kernel cake (PKC) is an abundant side stream that can only be added to non-ruminant feed in small concentrations due to its content of antinutritional factors, mainly galactomannan, which cannot be digested by non-ruminants. β-mannanases can be added to partially hydrolyze galactomannan to form mannose oligosaccharides, which are known to be prebiotic. We here investigate the action of a β-mannanase from B. subtilis on PKC by colorimetry, NMR and fluorescence microscopy. The amount of mannan oligosaccharides in solution was significantly increased by the β-mannanase and their degree of polymerization (DP) was significantly reduced. There was a dose-response behavior in that larger β-mannanase concentrations increased the amount of soluble mannose oligosaccharides while reducing their average DP. Using confocal immunofluorescence microscopy, solubilization of galactomannan in PKC was clearly visualized. Images show a clear disruption of the cellulose and galactomannan structures of the PKC cell walls. We thus show in this study that using commercial dosages of β-mannanase on PKC can lead to formation of prebiotic compounds. Thus, this study suggests that utilization of PKC in poultry feed formulation might be increased by addition of a β-mannanase and would improve the return on investment.

KW - Cage effect

KW - Mannan

KW - Mannan oligosaccharides

KW - Non-starch polysaccharides

KW - Palm kernel

KW - Prebiotic

KW - β-mannanase

U2 - 10.3390/molecules27020563

DO - 10.3390/molecules27020563

M3 - Journal article

C2 - 35056877

AN - SCOPUS:85122975109

VL - 27

JO - Molecules

JF - Molecules

SN - 1420-3049

IS - 2

M1 - 563

ER -