Product solubility control in cellooligosaccharide production by coupled cellobiose and cellodextrin phosphorylase

We provide here the underlying data of the scientific publication "Product solubility control in cellooligosaccharide production by coupled cellobiose and cellodextrin phosphorylase". Please find the abstract below:

Soluble cellodextrins (linear β‐1,4‐D‐gluco‐oligosaccharides) have interesting
applications as ingredients for human and animal nutrition. Their bottom‐up synthesis
from glucose is promising for bulk production, but to ensure a completely watersoluble
product via degree of polymerization (DP) control (DP ≤ 6) is challenging.
Here, we show biocatalytic production of cellodextrins with DP centered at 3 to 6
(~96 wt.% of total product) using coupled cellobiose and cellodextrin phosphorylase.
The cascade reaction, wherein glucose was elongated sequentially from α‐glucose
1‐phosphate (αGlc1‐P), required optimization and control at two main points. First,
kinetic and thermodynamic restrictions upon αGlc1‐P utilization (200 mM; 45°C,
pH 7.0) were effectively overcome (53% → ≥90% conversion after 10 hrs of reaction)
by in situ removal of the phosphate released via precipitation with Mg2+. Second, the
product DP was controlled by the molar ratio of glucose/αGlc1‐P (∼0.25; 50mM
glucose) used in the reaction. In optimized conversion, soluble cellodextrins in a total
product concentration of 36 g/L were obtained through efficient utilization of the
substrates used (glucose: 98%; αGlc1‐P: ∼80%) after 1 hr of reaction. We also showed
that, by keeping the glucose concentration low (i.e., 1–10 mM; 200mM αGlc1‐P), the
reaction was shifted completely towards insoluble product formation (DP ∼9–10). In
summary, this study provides the basis for an efficient and product DP‐controlled
biocatalytic synthesis of cellodextrins from expedient substrates.