Production of fructo-oligosaccharides by Aspergillus ibericus and their chemical characterization

• DOI: 10.1016/j.lwt.2017.10.015
• Publication Date: 2017-10-13T10:15:32Z
• Authors: C. Nobre; E.G. Alves Filho; F.A.N. Fernandes; E.S. Brito; S. Rodrigues; J.A. Teixeira; L.R. Rodrigues
• Keywords: Production yield optimization; 0106 biological sciences; Science & Technology; Chemical structure; Fructo-oligosaccharides; 01 natural sciences; Aspergillus ibericus; Experimental design

Abstract A great demand for prebiotics is driving the search for new sources of fructo-oligosaccharides (FOS) producers and for FOS with differentiated functionalities. In the present work, FOS production by a new isolated strain of Aspergillus ibericus was evaluated. The temperature of fermentation and initial pH were optimized in shaken flask to yield a maximal FOS production, through a central composite experimental design. FOS were produced in a one-step bioprocess using the whole cells of the microorganism. The model (R2 = 0.918) predicted a yield of 0.56, experimentally 0.53 ± 0.03 gFOS.ginitial sucrose−1 was obtained (37.0 °C and a pH of 6.2). A yield of 0.64 ± 0.02 gFOS.ginitial sucrose−1 was obtained in the bioreactor, at 38 h, with a content of 118 ± 4 g.L−1 in FOS and a purity of 56 ± 3%. The chemical structure of the FOS produced by A. ibericus was determined by HPLC and NMR. FOS were identified as 1-kestose, nystose, and 1F-fructofuranosylnystose. In conclusion, A. ibericus was found to be a good alternative FOS producer.