Ultrafiltration operational conditions influence in the antibacterial activity of native and thermally treated lysozyme

Abstract

. To obtain high quality final products, biomolecules can be exposed in production lines to stress factors such as heating, stirring and multiple surfaces contact before their commercialization. These factors can induce stability and e ffi cacy loss. In this work, the antibacterial activity of lysozyme (LSZ),aproteinusedasantibioticwhichactsbydisruptingthebacterialcellwall,wasstudiedaftertwo operations: heating and ultrafiltration. Antibacterial activity after extreme stress factors is expected to decrease due to conformational changes in the protein molecule. It was observed that ultrafiltration can promote an activity decrease proportional to the applied transmembrane pressure of a non-treatedlysozyme.However,whenathermallytreatedlysozyme(90°C)wasfiltered,noadditionale ff ect was observed due to the pore passage, independently of the applied pressure.