Groebe, A.A.GroebeChmiel, H.H.ChmielStrathmann, H.H.Strathmann2022-03-082022-03-081992https://publica.fraunhofer.de/handle/publica/302717The invention relates to a process for the production of membranes made of bacterially produced cellulose and the use of said membranes for separation operations such as, e.g. for microfiltration or ultrafiltration. Acetic-acid bacteria forming cellulose at temperatures between 18 and 35 <degrees Celsius>C emersed in static cultures at pH between 5.5 and 6.5 on culture media containing carbon sources utilizable by the bacteria, utilizable proteins and mineral nutrients; morphologically non-uniform cellulose layers which may be formed on the culture media by the bacteria during an exponential growth phase of the bacteria are removed and discarded, and the morphologically uniform cellulose layers formed by the bacteria on the culture media during the stationary growth phase of the bacteria are isolated and cleaned. Depending on the supply of nutrient for the bacteria, cellulose membranes are contained having uniform fibrillary or globular structures. With a constant supply of nutrient, c ellulose membranes with uniform layer thickness are obtained.de608610620660patent1989-3929369