A new approach to purification of bacterial cellulose membranes: What happens to bacteria in supercritical media?

Abstract

In this paper, we report our attempts to elaborate the method of purification and simultaneous sterilization of bacterial cellulose films by means of processing them under high pressure, including supercritical conditions for carbon dioxide, for future application in medicine. Bacterial cellulose films were produced by Gluconacetobacter hansenii. The processed samples were controlled by means of AFM, SEM, EDS, IR spectrometry, elemental and microbiological analysis.It was shown that conventional methods do not always provide complete removal of cells and endotoxins and the samples contain traces of compounds used for washing. It was revealed that the outer lipopolysaccharide membrane of the producent cells was destroyed during processing, but bacterial cells still preserved their shape and dimensions. The processed samples were sterile; the level of endotoxins was strongly reduced, though, unfortunately the degree of purification required for medical use was not achieved.