Elaboration and characterization of low cost ceramics microfiltration membranes applied to the sterilization of plant tissue culture media

The prevention of contamination of tissue culture media is important for the whole process of plant propagation and helps decrease the spread of plant microorganisms. Because of the high cost and undesirable effects of techniques currently used to sterilize culture media, some efforts are made to develop alternative methods such as sterile filtration. In this work, multilayer membranes for the sterilization of nutrient medium have been prepared from ceramic materials. Tubular and flat ceramic supports for membranes were prepared and sintered at 1200 and 1250 degrees C. Using slip casting technique, two layers were deposited on the supports. Both anorthite intermediate layer and zirconia (ZrO2) top-layer were sintered at 1150 and 1100 degrees C, respectively. The average pore size of the top-layer membranes was about 0.3 mu m. The prepared multilayer ZrO2 and anorthite membranes showed a good performance in water separation. No evidence of microbial growth was observed in the filtrate sample which means that the ceramics membrane has completely eliminated microflora from the medium culture. Furthermore, this filtration allowed preserving the quality of organic thermo-labile substances. These results suggest that the membrane sterilization method is simple, inexpensive, non-destructive and is a good way of quickly sterilizing solutions without heating. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.