Microwave subcritical water pre-treatment and enzymatic hydrolysis of geographical identification (GI) tag Indian black rice (Chakhao Poireiton) straw for fermentable sugar production

Moirangthem, Kamaljit; Zaky, Abdelrahman S.; Tucker, Gregory A.

Abstract

Rice straw is an important feedstock for second-generation biorefineries, the majority being conventional white rice. This research investigated the potential of the straw of black rice Chakhao Poireiton, a rice variety of increasing importance, for biorefining. Pre-treatment of black rice straw was carried out in a pressurised microwave reactor and free sugar release was measured following digestion with Cellic® CTec3. This was compared to white rice straw. Pre-treatment (100 − 200° C for 5 min) did not drastically impact the sugar composition but brought about an enhanced release of glucose after enzymatic hydrolysis from 25 to 50% (black rice) and from 26 to 55% (white rice). For xylose digestibility, the increase was around seven-fold for black rice (8 to 57%) and five-fold for white rice (13 to 64%). This improvement in digestibility of the straw samples could have come from modification in the lignocellulose structural features making the polysaccharides more susceptible to hydrolysis. Black rice could be a suitable feedstock for a combined biorefinery–food and nutraceuticals from grain (much higher than white rice) and the straw for fermentable sugars comparable to white rice straw for biofuels.

Citation

Moirangthem, K., Zaky, A. S., & Tucker, G. A. (2022). Microwave subcritical water pre-treatment and enzymatic hydrolysis of geographical identification (GI) tag Indian black rice (Chakhao Poireiton) straw for fermentable sugar production. Biofuels, https://doi.org/10.1080/17597269.2021.1955585

• Journal Article Type: Article
• Acceptance Date: Jul 10, 2021
• Online Publication Date: Jul 21, 2021
• Publication Date: 2022
• Deposit Date: Aug 6, 2021
• Publicly Available Date: Jul 22, 2022
• Journal: Biofuels
• Print ISSN: 1759-7269
• Electronic ISSN: 1759-7277
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1080/17597269.2021.1955585
• Keywords: Waste Management and Disposal; Renewable Energy, Sustainability and the Environment
• Public URL: https://nottingham-repository.worktribe.com/output/5957347
• Publisher URL: https://www.tandfonline.com/doi/abs/10.1080/17597269.2021.1955585?journalCode=tbfu20
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Biofuels on 21/07/2021, available online: https://www.tandfonline.com/doi/abs/10.1080/17597269.2021.1955585?journalCode=tbfu20