title: β-Mannanase production by Aspergillus niger BCC4525 and its efficacy on broiler performance.
abstract: BACKGROUND
  Mannan is a hemicellulose constituent commonly found in plant-derived feed ingredients. The gum-like property of mannan can obstruct digestive enzymes and bile acids, resulting in impaired nutrient utilisation. In this study, β-mannanase production by Aspergillus niger strain BCC4525 was investigated using several agricultural residues under solid state condition. The biochemical properties of the target enzyme and the effects of enzyme supplementation on broiler performance and energy utilisation were assessed.
  
  
  RESULTS
  Among five carbon sources tested, copra meal was found to be the best carbon source for β-mannanase production with the maximum yield of 1837.5 U g(-1) . The crude β-mannanase exhibited maximum activity at 80 °C within a broad range of pH from 2 to 6. In vitro digestibility assay, which simulates the gastrointestinal tract system of broilers, showed that β-mannanase could liberate reducing sugars from corn/soybean diet. Surprisingly, β-mannanase supplementation had no significant effect on broiler feed intake, feed conversion rate or energy utilisation.
  
  
  CONCLUSIONS
  A high level of β-mannanase was produced by A. niger BCC4525 under solid state condition using copra meal as carbon source. Although the enzyme has the desired properties of an enzyme additive for improving broiler performance, it does not appear to be beneficial.
authors.affiliation: Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.
authors.forename: Warasirin
authors.initials: W
authors.lastname: Sornlake
authors.forename: Panida
authors.initials: P
authors.lastname: Matetaviparee
authors.forename: Nakul
authors.initials: N
authors.lastname: Rattanaphan
authors.forename: Sutipa
authors.initials: S
authors.lastname: Tanapongpipat
authors.forename: Lily
authors.initials: L
authors.lastname: Eurwilaichitr
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001234:Aspergillus niger / Q000201:enzymology*; D002645:Chickens / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004063:Digestion / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000378:metabolism; D008351:Mannans / Q000378:metabolism; D044902:beta-Mannosidase / Q000008:administration & dosage* / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D008351:Mannans; D044902:beta-Mannosidase
keywords: Aspergillus niger; broiler performance; feed enzyme; β-mannanase