Encapsulated Phytase Produced by Recombinant Yarrowia lipolytica Exhibits High Efficiency on Broiler Chickens in Low Dosage

Abstract

Phytases are the largest group of feed enzymes increasing the accessibility of organic phosphorus for the animals. Feed phytases are usually sold as dried powder of secreting producers, mainly micellar fungi. We proposed a new technology for producing phytase from Obesumbacterium proteus (OPP) in yeast Yarrowia lipolytica as cytosolic protein (encapsulated OPP), where the capsule (yeast cell) protects the enzyme from unfavourable factors (acid medium and active proteolysis in stomachs) and releases it along with the substrate in the duodenum only. Here we report results of testing the encapsulated OPP on the model of a broiler chicken in comparison to a conventional phytase from Aspergillus ficuum. The encapsulated OPP at a dosage of 30 FYT/kg provided the maximum body weight of the chicken in the end of experiment equal or somewhat higher than in the control group, where the available phosphorus deficit was complemented with a mineral phosphorus supply. In contrast, the conventional soluble phytase at a dosage of 100 or 1000 FYT/kg was not able to compensate for the phosphorus deficit in the diet, although chemical analysis demonstrated much phosphorus in the diet in a non-accessible form. The encapsulated OPP decreased the residual Pi in the chicken faeces by 2.1 times in comparison to the control when added to the diet, whereas the conventional phytases negligibly affected this parameter regardless of the dosage.