Production of bacterial cellulose with Gluconacetobacter xylinus in a membrane proces
Michael Hofinger, doctoral thesis Technische Universität München, 2011
A novel membrane process for the defined production of a hydrogel ("pellicle") of bacterial cellulose for biomedical applications was developed and the microbial cellulose production was characterized as function of the reaction conditions. Specifically, Gluconacetobacter xylinus converts glucose into a homogeneous cellulose pellicle at the liquid-gas interface on top of a hydrophilic microfiltration membrane. Below the membrane, the reaction medium can be mixed and the reaction conditions can thus be controlled easily. The height of the growing pellicle was measured online by means of a laser triangulation sensor. Under suitable reaction conditions Gluconacetobacter xylinus is able to produce homogeneous cellulose pellicles with a constant rate of more than 0.5 mm per day. The cellulose layers of the pellicle are arranged in parallel to the microfiltration membrane each of which showing a distance of about 5 µm.