Preparation of fructooligosaccharides using Aspergillus niger 6640 whole-cell as catalyst for bio-transformation

Fructooligosaccharides (FOS) have received particular interest because of their biological and functional properties as dietary fibres and their potential utilization as prebiotic compounds. In this research FOS were produced from sucrose using dried Aspergillus niger CGMCC 6640 mycelia containing β-fructofuranosidas (FFases) as a whole-cell catalyst. To support production of FOS bio-transformed by A. niger 6640, the effects of production parameters on the bio-transformation of sucrose as substrate were investigated using HPLC. It was established that the whole-cell and sucrose content positively affected the maximum FOS yield. However, the CaCl₂ content in the biocatalysts media negatively affected FOS yield. When the content of whole-cell biocatalysts was 60 g/L, the sucrose content was 600 g/L, 314.60 g/L of absolute content of FOS was obtained and the relative percentage was 51.11% at pH 7.0, 33 °C for 40 h. Results demonstrate that the whole-cell biocatalyst of A. niger 6640 can produce FOS effectively. The enzyme protein was extracted and purified, the molecular weight of β-fructofuranosidase from A. niger 6640 was around 75 kDa by SDS-PAGE. In summary, production FOS using the whole-cell mixture as biocatalyst was feasible and promised industrial application prospects