title: Protein profiles of hatchery egg shell membrane.
abstract: BACKGROUND
  Eggshells which consist largely of calcareous outer shell and shell membranes, constitute a significant part of poultry hatchery waste. The shell membranes (ESM) not only contain proteins that originate from egg whites but also from the developing embryos and different contaminants of microbial and environmental origins. As feed supplements, during post hatch growth, the hatchery egg shell membranes (HESM) have shown potential for imparting resistance of chickens to endotoxin stress and exert positive health effects. Considering that these effects are mediated by the bioactive proteins and peptides present in the membrane, the objective of the study was to identify the protein profiles of hatchery eggshell membranes (HESM).
  
  
  METHODS
  Hatchery egg shell membranes were extracted with acidified methanol and a guanidine hydrochloride buffer then subjected to reduction/alkylation, and trypsin digestion. The methanol extract was additionally analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). The tryptic digests were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS-MS) to identify the proteins.
  
  
  RESULTS
  Our results showed the presence of several proteins that are inherent and abundant in egg white such as, ovalbumin, ovotransferrin, ovocleidin-116, and lysozyme, and several proteins associated with cytoskeletal, cell signaling, antimicrobial, and catalytic functions involving carbohydrate, nucleic acid, and protein metabolisms. There were some blood derived proteins most likely originating from the embryos and several other proteins identified with different aerobic, anaerobic, gram positive, gram negative, soil, and marine bacterial species some commensals and others zoonotic.
  
  
  CONCLUSIONS
  The variety of bioactive proteins, particularly the cell signaling and enzymatic proteins along with the diverse microbial proteins, make the HESM suitable for nutritional and biological application to improve post hatch immunity of poultry.
authors.affiliation: USDA/Agricultural Research Service, Poultry Production and Product Safety Research Unit, Fayetteville, AR 72701 USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Rath
authors.affiliation: Statewide Mass Spectrometry Facility, University of Arkansas, Fayetteville, AR 72701 USA.
authors.forename: R
authors.initials: R
authors.lastname: Liyanage
authors.affiliation: Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701 USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Makkar
authors.affiliation: Statewide Mass Spectrometry Facility, University of Arkansas, Fayetteville, AR 72701 USA.
authors.forename: J O
authors.initials: JO
authors.lastname: Lay
keywords: Hatchery egg shell membrane; Mass spectrometry; Proteins