title: Improvement in Saccharification Yield of Mixed Rumen Enzymes by Identification of Recalcitrant Cell Wall Constituents Using Enzyme Fingerprinting.
abstract: Identification of recalcitrant factors that limit digestion of forages and the development of enzymatic approaches that improve hydrolysis could play a key role in improving the efficiency of meat and milk production in ruminants. Enzyme fingerprinting of barley silage fed to heifers and total tract indigestible fibre residue (TIFR) collected from feces was used to identify cell wall components resistant to total tract digestion. Enzyme fingerprinting results identified acetyl xylan esterases as key to the enhanced ruminal digestion. FTIR analysis also suggested cross-link cell wall polymers as principal components of indigested fiber residues in feces. Based on structural information from enzymatic fingerprinting and FTIR, enzyme pretreatment to enhance glucose yield from barley straw and alfalfa hay upon exposure to mixed rumen-enzymes was developed. Prehydrolysis effects of recombinant fungal fibrolytic hydrolases were analyzed using microassay in combination with statistical experimental design. Recombinant hemicellulases and auxiliary enzymes initiated degradation of plant structural polysaccharides upon application and improved the in vitro saccharification of alfalfa and barley straw by mixed rumen enzymes. The validation results showed that microassay in combination with statistical experimental design can be successfully used to predict effective enzyme pretreatments that can enhance plant cell wall digestion by mixed rumen enzymes.
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada T1H 4P4.
authors.forename: Ajay
authors.initials: A
authors.lastname: Badhan
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada T1H 4P4.
authors.forename: Yu-Xi
authors.initials: YX
authors.lastname: Wang
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada T1H 4P4.
authors.forename: Robert
authors.initials: R
authors.lastname: Gruninger
authors.affiliation: Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada H4B 1R6.
authors.forename: Donald
authors.initials: D
authors.lastname: Patton
authors.affiliation: Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada H4B 1R6.
authors.forename: Justin
authors.initials: J
authors.lastname: Powlowski
authors.affiliation: Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada H4B 1R6.
authors.forename: Adrian
authors.initials: A
authors.lastname: Tsang
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada T1H 4P4.
authors.forename: Tim A
authors.initials: TA
authors.lastname: McAllister
mesh_terms: D000115:Acetylesterase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D004063:Digestion / Q000502:physiology*; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000378:metabolism*; D001467:Hordeum / Q000737:chemistry; D008954:Models, Biological; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D012417:Rumen / Q000737:chemistry / Q000201:enzymology*
chemical_list: D011134:Polysaccharides; D000115:Acetylesterase; C081851:acetylxylan esterase; D006026:Glycoside Hydrolases; C023305:hemicellulase; D005947:Glucose