Fermentation process and isolation of extracellular glucan using Claviceps species fungi

摘要

In the present invention, there is disclosed a fermentation process and isolation of extracellular glucan using Claviceps species fungi wherein the process is characterized in that Claviceps species fungi are used as a producer producing exopolysaccharides and which does not produce alkaloids and like biologically active substances, particularly from a group of Claviceps viridis and Claviceps maximensis species. Submersion cultivation is carried out at a temperature ranging from 18 to 28 degC, on a synthetic culture medium, biomass of the production microorganism is then removed after fermentation from the culture liquid by filtration or centrifugation and the retenate is stabilized after dialysis to a final appearance by lyophilization. A non-amorphous glucan form is prepared in such a manner that the retenate is exposed to the action of a direct current within an electrocoagulation device with an iron or aluminium sacrificed electrode at current density ranging from 0.05 to 0.8 mA/cme2 of surface of immersed electrodes at voltage gradient in the range of 0.2 to 2 V/cm of a distance between two electrodes, or in the electrocoagulation device, there can be used stainless steel electrodes and heavy metal salts are added to the solution, preferably aluminium, copper, iron, cadmium or lead salts in an amount ranging from 2 to 15 ml of the salt saturated solution per 1 liter of the culture liquid.