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Globally, the demands for sustainably sourced functional foods like prebiotic oligosaccharides have been constantly increasing. This study assessed the potential of pineapple leaves (PL) as lignocellulosic feedstock for sustainable production of cellulose and hemicellulose-derived oligosaccharides through its hydrothermal pretreatment (HT) followed by controlled enzymatic hydrolysis. PL was subjected to HT at 160, 175, and 190 °C for 20, 30, 60, and 90 min without any catalyst for xylooligosaccharide (XOS) production, whereas, the resulting solid content after HT was subjected to controlled enzymatic hydrolysis by commercial cellulase using conduritol B epoxide (0.5-5 mM) for glucooligosaccharides (GOS) production. HT at 160 °C for 60 min resulted in maximum yield of XOS and GOS at 23.7 and 18.3 %, respectively, in the liquid phase. Controlled enzymatic hydrolysis of HT treated (160 °C) PL solids for 20 and 30 min yielded ∼ 174 mg cellobiose/g dry biomass within 24 h, indicating overall high oligosaccharide production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

[Display omitted] • Hydrothermal combined with mild acid allowed the recovery of xylooligosaccharides. • XOS yield of 67.79% was obtained with 5% gluconic acid at 160 °C for 60 min. • Glucose obtained after enzymatic hydrolysis was used for the production of BC. • BC production with XOS can be integrated for sustainable circular bioprocess. A hydrothermal process is a sustainable approach for biorefinery leading to conversion of lignocellulosic (LC) biomass into value-added products. This study is based on the production of xylooligosaccharides (XOS) from pineapple leaves (PL) waste by using mild acid like gluconic acid (GA). GA, when used as catalyst in hydrothermal process to produce XOS the yield improved. The above process can be integrated with bacterial cellulose (BC) production bioprocess via Komagataeibacter europaeus 14,148 where gluconic acid is produced as by-product. Maximum XOS (2–5 degree of polymerisation) yield of 67.79 % in the liquid fraction was obtained via hydrothermal treatment at 160 °C for 60 min with 5% gluconic acid concentration. It is based on the selective solubilization of hemicellulose fraction. Enzymatic hydrolysis of GA hydrothermally pretreated solid fraction of PL biomass gave 14.5 g/L glucose with 5% solid loading and 10 FPU/gds enzyme loading which was employed for Bacterial cellulose production. [ABSTRACT FROM AUTHOR]

Co-culture of fungal strains Penicillium janthinellum EMS-UV-8 (E), Penicillium funiculosum strain P (P) and Aspergillus sp. strain G (G) and blending of their crude cellulase were evaluated for improvements in cellulase activities as well as for enhanced hydrolysis of dilute acid pretreated wheat straw (PWS). The blending of crude enzymes of P and E enhanced the hydrolysis of PWS more effectively due to synergism in cellulolytic enzyme activities. Here, three types of blends were made on the basis of equal FPUs, equal protein content or fixed volume containing different proportions of individual enzymes, the former blend hydrolyzed 42.6% of PWS due to the 98%,62%, 64% and 34% synergistic enhancement in endo-glucanase, cellulase (FPU), β-glucosidase and xylanase activities, respectively. Hydrolysis at 10% solid loading of PWS in roller bottle reactor with this blend further enhanced hydrolysis yield to 74% within 24 h, which was much better than the corresponding hydrolysis yields of individual (38.1% by E and 61.5% by P) or the commercial enzyme (62.3%). This study proved that synergistic blends of cellulases from two Penicillium spp. are cost-effective tools for efficient wheat straw hydrolysis for on-site biofuel production. [ABSTRACT FROM AUTHOR]