Enzymatic Activities of C. uda Fermentation

C. uda has the capability of expressing cellulose and hemicellulose degrading enzymes [11 (link), 12 (link), 58 (link)]. The cellulase activity of the fermentation broth was measured by a filter paper assay as described previously for a general approach [59 ]. Nevertheless, the assay was adjusted to the requirements of the present process as follows: (I) 0.2 M MOPS buffer pH = 7.4 was applied instead of citrate buffer and (II) 6 cm⁻² of filter paper (Whatman grade 1, Whatman plc, Little Chalfont, United Kingdom), 1 mL MOPS buffer and 1 mL of culture broth were incubated at 313 K and 1400 rpm for 240 min (Thermomixer‐compact, Eppendorf AG, Hamburg, Germany).
The xylanase activity was determined according to Rapp and Wagner [12 (link)] with some modifications: (I) 0.05 M sodium citrate buffer pH = 5 was applied instead of phosphate buffer in order to produce the 0.7 w% xylan testing solution and (II) 1 mL of culture broth and 1 mL of xylan solution were incubated at 323 K for 90 min.
The enzymatic reaction was stopped after the incubation period by heating up the sample to 368 K for 10 min. Sugar concentrations (cellobiose and xylose) were determined using HPLC, as described in the supporting information.
The enzymatic activity A, both for cellulase and for xylanase, was determined according to the Equation (2).
$$\begin{array}{c}\hfill A=\frac{(c_{Sugar,Assay}-0.5·c_{Sugar,Fermentation})·V_{Assay}}{M_{Sugar}·t_{Assay}}·16.67\end{array}$$