Author/Authors :
Onilude, A. A. University of Ibadan - Department of Microbiology, Microbial Physiology and Biochemistry Laboratory, Nigeria , Olaoye, O. Federal Polytechnic Offa - Department of Food Technology, Nigeria , Fadahunsi, I.F. University of Ibadan - Department of Microbiology, Microbial Physiology and Biochemistry Laboratory, Nigeria , Owoseni, A. Bowen University Iwo - Department of Biological Sciences, Nigeria , Garuba, E.O. Bowen University Iwo - Department of Biological Sciences, Nigeria , Atoyebi, T. University of Ibadan - Department of Microbiology, Microbial Physiology and Biochemistry Laboratory, Nigeria
Abstract :
In this study, attempts were made to investigate the influence of various cultural conditions such as sources of carbon and nitrogen, vitamins, amino acids, initial pH of the medium, temperature of incubation and agitation on dextran production by a recently isolated species of Leuconostoc. Among the various carbon source studies, potato peels at a concentration of 20% (w/v) gave the highest amount of dextran (7.9 g/100 ml) while corn steep liquor-containing medium gave the lowest amount of dextran. The effect of various nitrogen sources revealed that casein at 0.5% (w/v) enhanced the highest (8.5 g/100 ml) production of dextran while the lowest amount (3.3 g/100 ml) was recorded in a medium containing urea. The effects of vitamins and amino acids revealed that ascorbic acid and glutamic acid at a concentration of 0.05% gave the highest dextran production of 8.3 g/100 ml and 8.2 g/100 ml respectively. Inoculum size of 6% was found to be optimum for dextran production (9.2 g/100 ml) by this Leuconostoc spp while an incubation time of 20 h produced the highest dextran weight of 8.0 g/100 ml. The effect of initial pH of the medium and temperature of incubation of the culture revealed that pH 6.5 and incubation at 25°C gave the optimum dextran production of 8.2 g /100 ml each.
Keywords :
Dextran , Leuconostoc spp. Potato peels , Casein , Temperature , pH
