Bacterial xylanase expression in mammalian cells and transgenic mice

The energy which simple-stomached livestock can derive from dietary plant m aterial is limited by the lack of plant polysaccharide degrading enzymes in their gastro-intestinal (GI) tract and the inefficient microbial fermentat ion of such material in their hind-gut. In poultry the non-starch polysacch arides found in cereal grains can also impair normal digestive function as they form viscous gels in the GI tract inhibiting the breakdown and absorpt ion of nutrients, The nutrition of such livestock could, therefore, be impr oved by the introduction of enzymes able to degrade plant polysaccharides i n the small intestine. We describe the expression of a xylanase, XYLY', fro m the bacterium Clostridium thermocellum in mammalian cells and the exocrin e pancreas of transgenic mice. The enzyme is synthesised, secreted and func tionally active in the eukaryote system. This work demonstrates the feasibi lity of generating animals with the endogenous capacity to depolymerise the xylan component of hemi-cellulose. (C) 1999 Elsevier Science B.V. All righ ts reserved.