Production of bacterial cellulose by Gluconacetobacter hansenii using a novel bioreactor equipped with a spin filter

Abstract

In order to improve bacterial cellulose (BC) production yield by increasing the cell density, a new fermentation system using a spin filter was developed and its performance characteristics were tested. Fermentations were carried out in a fermenter equipped with a 6 flat-blade turbine impeller and a spin filter consisting of a cylinder surrounded by stainless steel mesh and whose stainless steel bottom was attached to the agitator shaft. This new fermentation assembly was tested under different experimental conditions for BC production by Gluconacetobacter hansenii PJK. In periodical perfusion culture without pH control, the BC production and the total cell mass increased with the culture time to 3.07 and 5.65 g/L, respectively, at 140 h of cultivation. The BC production was also tested at adjusted pH and pH 5 was found optimum for maximum BC production. At pH 5, in periodical perfusion culture, the BC production and the total cell mass reached to 4.57 and 11.52 g/L, respectively, after 140 h of cultivation. This amount of BC production was 2.9 times higher than that obtained in a conventional jar fermenter. The productivity improved and was 0.044 g/L . h at 68 h of cultivation.