- Increase in extracellular inulinase production for a new Rhizoctonia ssp. strain by using buckwheat (Fagopyrum esculentum) flour as a single carbon source.
Increase in extracellular inulinase production for a new Rhizoctonia ssp. strain by using buckwheat (Fagopyrum esculentum) flour as a single carbon source.
A newly isolated strain of Rhizoctonia ssp. was used for the production of extracellular inulinase. Previously, the qualitative effects of some carbon and nitrogen sources from fermentative media and the physicochemical parameters for growth were established by Plackett-Burman analysis, and the main parameters that affect extracellular inulinase yield were identified. In this study, the quantitative effect of the carbon to nitrogen ratio in the fermentative medium and the growth temperature were studied and optimized using central composite design and response surface methodology. On the basis of optimization, the maximum extracellular inulinase activity was achieved when 2Ā·5-6Ā·5% buckwheat flour was used as a single carbon source and 4Ā·6-5Ā·0% yeast extract was used as nitrogen source, by submerged cultivation, after 48 h at an incubation temperature between 15 and 27Ā·5Ā°C. Under the fermentative conditions established in this study, a maximum extracellular inulinase yield of 1Ā·8 UI mlā»Ā¹ was achieved. Rhizoctonia ssp. strain can be used for extracellular inulinase production. Also, buckwheat flour proved to be an inexpensive and abundant substrate suitable for obtaining inulinase. Inulinases are versatile tools for biotechnology as they can be used for a wide range of applications, including production of bioethanol, fructose syrup and inulo-oligosaccharides, lactic acid, citric acid and butanediol.