One-step co-culture fermentation strategy to produce high-content fructo-oligosaccharides

Abstract

An integrated process enabling the simultaneous production and purification of fructo-oligosaccharides (FOS) was explored. A co-culture fermentation with Aspergillus ibericus (used as FOS producer strain) and Saccharomyces cerevisiae YIL162 W (for small saccharides removal) was optimized. Inoculation conditions of S. cerevisiae, fermentative broth composition, temperature and pH were optimized by experimental design. Yeast extract concentration and temperature were the most significant variables affecting FOS purity. Co-culture fermentations with simultaneously inoculation of the strains, run under 30 °C, initial pH 6.0 and 17 g L yeast extract led to FOS mixtures with 97.4 ± 0.2% (w/w) purity. The fermentations conducted in bioreactor, at a 0.8 vvm aeration rate, yielded 0.70 ± 0.00 g.g at 45 h fermentation, with a FOS content of 133.7 ± 0.1 g L. A purity of FOS up to 93.8 ± 0.7% (w/w) was achieved. The one-step fermentation proved to be efficient, economical and fast.

Removal of Small-Molecular Byproducts from Crude Fructo-Oligosaccharide Preparations by Fermentation Using the Endospore-Forming Probiotic Bacillus coagulans

“…Microbial treatment is an increasingly attractive solution for the purification and enrichment of oligosaccharides from a crude preparation [23,32,35,[58][59][60]. Most previous studies involved sequential fermentation (or co-fermentation) with yeast such as S. cerevisae, K. lactis, and Pichia pastoris to remove the small sugars, increasing the purity and content of oligosaccharides.…”

Microbial co-culturing strategies for fructo-oligosaccharide production

“…On the other hand, in a medium with high glucose, the SUC2 is repressed and the yeast starts consuming mainly glucose instead of sucrose. In order to better understand the impact of both microorganisms on the fermentation mixture, the use of a yeast strain with a repressed SUC2 gene, such as S. cerevisiae YIL162 W (as reported by [14]), was suggested [26].…”

“…Two different approaches have mainly been used: (i) systems consisting of two mixed enzymes, e.g. β-fructofuranosidase with glucose oxidase [4,10,11]; (ii) co-culture systems with two microorganisms, one FOS-producer and the second a small saccharides consumer: Aspergillus japonicus and Pichia pastoris [12], A. japonicus and Pichia heimii immobilised in calcium-alginate beads [13], and Aspergillus ibericus and S. cerevisiae YIL162 W (with the gene responsible for sucrose hydrolysis disrupted) [14]. In recent work, a co-culture of A. pullulans with Saccharomyces cerevisiae was tested; the yeast was able to reduce the amount of small sugars in the mixture, although the amount of FOS produced also decreased [3].…”

Fermentative Production of Fructo-Oligosaccharides Using Aureobasidium pullulans: Effect of Dissolved Oxygen Concentration and Fermentation Mode

“…The FOS are then produced under controlled conditions with the extracted enzymes using sucrose as the substrate [14][15][16]. During the one-stage process, FOS are biosynthesized from fungi in bioreactors using either immobilized or free whole cells as biocatalysts [4,6,[17][18][19]. The fermentative production of FOS using the one-stage process is advantageous when compared with the two-stage process because the step of purification of FOS-producing enzyme from cell extracts can be eliminated.…”