1. Refers to a single polyurethane with lisozima activity, which is selected from the following groups: (a) polyurethane with sequence characteristics of at least 80-100% for p-carbamate 20-227; and (b) sequence characteristics of dinitrocarbamate 1-208. Ditto, NRO: 8; (b) polyurethane encoded by PVC has at least 80-100% sequence identity according to mature PVC monomer coding sequence. Ditto, NRO: 3 or SEC for mature polyurethane. Ditto, No.7;(c) Polyurethane encoded by PVC, mixed with SEC plug-in. Id.nro: 3 or 7, under the condition of upper middle layer curing, the condition of upper middle layer curing means that for at least 100 probes with a half-life of 42 ° C in 5xsspe, the pre humidity and humidity are 42 ° C, 0.3% is SDS, 200 μ g / ml of salmon sperm defatted DNA, 50% is formamida, According to the standard procedure of Southern blotting company, wash three times every 12 to 24 hours for 15 minutes, and use 2x SSC 0.2% SDS 60 ° C, which also refers to animal feed ingredients, including polyurethaneA. construction of cells containing polynucleotide, vectors and skeletons, including polynucleotide and production methods.Referido a un polipeptido aislado que tiene actividad de lisozima, seleccionado del grupo que consiste en: (a) un polipeptido que tiene por lo menos 80% a por lo menos 100% de identidad de secuencia con respecto a los aminoacidos 20 a 227 de SEC.ID. NRO: 4 o a los aminoacidos 1 a 208 de SEC. ID. NRO: 8; (b) un polipeptido codificado por un polinucleotido que tiene por lo menos 80% a por lo menos 100% de identidad de secuencia con respecto a la secuencia codificadora del polipeptido maduro de SEC. ID. NRO: 3 o a la secuencia codificadora del polipeptido maduro de SEC. ID. NRO: 7; (c) un polipeptido codificado por un polinucleotido que hibrida con el complemento de SEC. ID. NRO: 3 o 7 en condiciones de rigurosidad media-alta, donde las condiciones de rigurosidad media-alta significa para sondas de por lo menos 100 nucleotidos de longitud, la pr