Experimental Assessment of the Impact of Cultivation Conditions on Kefiran Production by the Mixed Microflora Imbedded in Kefir Grains

摘要

The aim of this work was to investigate the environmental requirements for thernproduction of specific exopolysaccharide (EPS) kefiran from natural starter culture –rnkefir grains. We have found that the temperature and agitation rate are critical forrnkefiran production during the 24 h cultivation of kefir grains in full fat cow's milk; ourrnoptimized conditions were 25 ℃ and 80 rpm, respectively. In addition, when optimizingrnthe effects of additional nutrition, we found that 5 % (w/v) lactose and 0.1 % (w/v)rnthiamine led to the highest production of kefiran from kefir grains. The kefir grainsrnbiomass increase, kefiran mass fraction in the grains and mass ratio of glucose andrngalactose in kefiran reached 11.62 g/L, 1.65 % (w/w) and 1:0.82, respectively.