Composite biocatalysts (CB) consisting of amylases and Saccharomyces cerevisiae immobilized separately on bacterial nanocellulose (BNC) are used for the process of simultaneous saccharification and fermentation (SSF) of starch (5%, w/v) for bioethanol production. Parameters such as: i) addition of phosphates and/or divalent metal‐ions salts during the co‐immobilization process of the amylases, ii) required co‐immobilization time, iii) fermentation temperature and initial pH of starch, and iv) CB as single or double freeze‐dried are studied. The utilization of double freeze‐dried CB exhibits fermentation efficiency 89.9% and ethanol yield 0.51 g ethanol g−1 starch while the single freeze‐dried CB 81.1% and 0.46 g ethanol g−1 starch, respectively. In the case of double freeze‐dried CB, the fermentation efficiency decreases by only 27.1% in two‐recycling batches, while in the single freeze‐dried one decreases by 51.3%. The application of double freeze‐dried CB can be used for: i) the eco‐friendly biosynthesis of value‐added bioproducts; ii) the promising option for fuel‐grade bioethanol through starchy wastes or foodstuff starchy residues treatment, and iii) the implementation of industrialization. Finally, to simulate an industrial process of one‐step SSF of starch by applying a CB model, a technoeconomic analysis is evaluated, where using BNCs makes the bioprocess cost‐effective and environmentally favorable, simultaneously.
|Number of pages||11|
|Journal||Starch - Stärke|
|Early online date||3 Nov 2023|
|Publication status||Published online - 3 Nov 2023|
Bibliographical noteFunding Information:
The authors acknowledge the support of this work by the project “Research Infrastructure on Food Bioprocessing Development and Innovation Exploitation – Food Innovation RI” (MIS 5027222), which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure,” funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020) and co‐financed by Greece and the European Union (European Regional Development Fund).
© 2023 Wiley-VCH GmbH.
- freeze drying
- α- and β- amylases
- divalent metal ions
- simultaneous saccharification and fermentation
- bacterial nanocellulose