Microbial co-culturing strategies for fructo-oligosaccharide production

• Published in: New biotechnology Vol. 51; pp. 1 - 7
• Main Authors: Castro, Cristiana C., Nobre, Clarisse, De Weireld, Guy, Hantson, Anne-Lise
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25-07-2019; Elsevier; Elsevier Science Ltd
• Subjects: Aureobasidium pullulans; Bioreactors; Carbohydrates; Cell culture; Co-culture; Encapsulation; Ethanol; Fermentation; Fructo-oligosaccharides; Fructooligosaccharides; Glucose; Immobilisation strategy; Microorganisms; Mixed culture; Monoculture; Moving beds; Purification; Purity; Saccharides; Saccharomyces cerevisiae; Science & Technology; Sucrose; Sugar; Yeast; YGCb; YGCa; FTase; FFase; SMB; RPF; FOS; IT; Fructo-oligosaccharides; AP; SC; SCe; Aureobasidium pullulans; APe; APf; SCf; APi; Co-culture; Saccharomyces cerevisiae; Immobilisation strategy
• ISSN: 1871-6784; 1876-4347; 1871-6784
• DOI: 10.1016/j.nbt.2019.01.009

•Co-cultures of A. pullulans (AP) and S. cerevisiae (SC) were studied to produce FOS.•AP immobilized into RPF enhanced FOS production compared to free or Ca-alginate encapsulated cells.•Immobilized AP in co-culture with encapsulated SC, inoculated after 10 h, improved FOS production.•Maximal FOS concentration, yield and productivity were: 119 g L−1, 0.59 gFOS gGF−1 and 5.9 gFOS L−1 h−1.•Final fermentation mixture contained: 67% FOS, 23% fructose, 8% glucose and 2% (w/w) sucrose.
Fructo-oligosaccharide (FOS) mixtures produced by fermentation contain large amounts of non-prebiotic sugars. Here we propose a mixed culture of Aureobasidium pullulans and Saccharomyces cerevisiae cells to produce FOS and consume the small saccharides simultaneously, thereby increasing FOS purity in the mixture. The use of immobilised A. pullulans in co-culture with encapsulated S. cerevisiae, inoculated after 10 h fermentation, enhanced FOS production in a 5 L bioreactor. Using this strategy, a maximal FOS concentration of 119 g L−1, and yield of 0.59 gFOS gsucrose−1, were obtained after 20 h fermentation, increasing FOS productivity from about 4.9 to 5.9 gFOS L−1 h−1 compared to a control fermentation of immobilized A. pullulans in monoculture. In addition, the encapsulated S. cerevisiae cells were able to decrease the glucose in the medium to about 7.6% (w/w) after 63 h fermentation. This provided a final fermentation mixture with 2.0% (w/w) sucrose and a FOS purity of over 67.0% (w/w). Moreover, a concentration of up to 58.0 g L−1 of ethanol was obtained through the enzymatic transformation of glucose. The resulting pre-purified FOS mixture could improve the separation and purification of FOS in downstream treatments, such as simulated moving bed chromatography.