Optimized scleroglucan production by Athelia rolfsii and in vitro Sclg-5-fluorouracil release investigations

Abstract

Scleroglucan is a notable member of the β-glucan microbial polysaccharides with a long tradition of industrial and therapeutic use. The local strain, previously identified as Athelia rolfsii TEMG MH 236106 produced an appreciable amount of scleroglucan using glucose as a carbon source and yeast extract as a nitrogen source. Plackett-Burman design was employed to effectively screen critical medium composition, culture, and fermentation conditions. Athelia rolfsii TEMG MH 236106 produced the maximum amount of scleroglucan (18.12 g/L) with a 45.3 % glucose conversion. Out of the eleven variables, the most effective factors showing a high level of significance are as follows: glucose, yeast extract, citric acid, inoculum disc numbers, culture volume and incubation time. An update to maximize scleroglucan production in the central composite design for four parameters (glucose and yeast extract concentrations, disc number, medium volume and incubation time) with 31 runs was applied and the production of scleroglucan reached its maximum at 31.56 g/L with 78.9 % glucose conversion. Three models of Sclg-5-fluorouracil complexes have been employed to study in vitro drug release investigations. Hence, the Sclg-5-FU (5 and 10 mg/mL) models appeared to be the most suitable for drug administration due to their concentration and distribution within capsules.

Keywords: Plackett-Burman and central composite designs; Scleroglucan optimization; Sclg-5-fluorouracil release.