A comparative study of nutritional and environmental factors affecting extracellular and intracellular invertase production in candida utilis

Twenty-five strains of candida utilis were isolated from various varieties of vitis vinifera (black grapes),obtained from the local markets of lahore. strain kc-b10 showed maximum enzyme activity. five media,m1,m2,m3,m4 and m5 were screened for enzyme activity with kc-b10 m1 showed maximum invertase activity i.e. 25.2 ± 0.20 u/ml extracellular invertase,21.5 ± 0.40 u/ml intracellular invertase activity and dry cell mass 5.53 ± 0.03 g/l. the nutritional and environmental conditions were optimized for this medium using shake flask fermentation technique. after optimization of cultural conditions,the maximum enzyme activity of intracellular invertase (30.4 ± 0.47 u/ml) and extracellular invertase (49.4 ± 0.20 u/ml) with dry cell mass of 6.19 ± 0.01 g/l at 24 hrs incubation time,1.6% (w/v) sucrose concentration,1% yeast extract,ph 4,30°c temperature and 200 rpm agitation rate. an increase of 49% was observed in extracellular activity while an increase of 30% was observed in intracellular activity with an increase of 10% dry cell mass. invertase finds its uses in the confectionary and pharmaceutical industries. this study indicates that single organic source of nitrogen with a single carbon source and no other supplements are required for the optimum production of both types of invertases from candida utilis kc-b10. thereby resulting in the formation of an economically friendly optimized medium for production of invertases in pakistan,a third world country with a fast growing population and limited resources.