Sustainable Co-Production of Xylanase, Cellulase, and Pectinase through Agroindustrial Residue Valorization Using Solid-State Fermentation: A Techno-Economic Assessment

Abstract

This work describes the evaluation of the solid-state fermentation (SSF) bioprocess utilizing brewery spent grain (BSG) and apple pomace (AP) as carbon sources and matrices for microorganism growth to produce xylanase, pectinase, and cellulase. The process was assessed at a larger scale by designing a packed column-type bioreactor equipped with sensors for monitoring critical parameters such as CO2 concentration, humidity, and temperature. Then, process simulation was used to evaluate the techno-economic feasibility of the bioprocess at an industrial scale. The analysis centered on evaluating which formulation, primarily containing xylanase (scenario 1), pectinase (scenario 2), or cellulase (scenario 3), yielded the most promising results for advancing to the commercial stage. Additionally, a sensitivity analysis was conducted to explore the influence of variations in raw material costs and enzyme prices. The obtained results at a higher scale were within the expected results obtained under optimum conditions. Scenario 1 exhibited strong economic viability with further optimization potential (base case: 5000 kg/batch with an ROI of 37.59 %, payback time of 2.66 years, IRR of 26.8%, and net present value of USD 7,325,537). The sensitivity analysis revealed that changes in enzyme prices, particularly xylanase, could significantly influence the process’s profitability. This study also demonstrated the potential for cost optimization by selecting a more cost-effective inoculum media and optimizing water usage to enhance process efficiency and sustainability.

Maximizing Fungal Growth in State-of-the-Art Tray Solid-State Fermenter: Aeration Strategies Optimized for Enhanced Performance

“…The findings of this study present a contrast to previous research conducted by Sosa-Martinez et al (2024). Their work on solid-state fermentation in packedbed column fermenters with enhanced air circulation indicated elevated activities of a diverse array of hydrolases, including xylanases, cellulases and pectinases, produced by Aspergillus sp.…”

“…As technology continues to evolve and modernize, solid-state fermentation is poised to be closely associated with the design of solid-state fermenters, marking crucial progress and innovation in biotechnological processes and bioprocess engineering. Numerous configurations have been developed specifically for solid-state fermentation applications, including syringe-type fermenter (Costa et al, 2021), semi-continuous plug-flow systems (Wang et al, 2021), packed-bed (Mitchell et al, 2023;Pakaweerachat et al, 2023;Finkler et al, 2021a;Maiga et al, 2021;Casciatori et al, 2016), packed-bed column fermenter (Sosa-Martinez et al, 2024), tray (Dallastra et al, 2023;Sentis-More et al, 2023;Nascimento et al, 2021), trickle bed (Shahryani et al, 2019), multipurpose fixedbed (Sabrini et al, 2019), rotating drum (Dabaghi et al, 2021;Mahmoodi et al, 2019), column-tray (Hector et al, 2012), novel deep-bed cubical (Brijwani et al, 2011), multi-layer packed-bed (Mitchell et al, 2006), column (Jang and Yang, 2008), fluidised-bed (Foong et al, 2009), hexahedral modular (da Cunha et al, 2009), solid state fermentation reactor (Ano et al, 2009), horizontal rotary drum (Alam et al, 2009), continuous counter-current reactor (Varzakas et al, 2008), scrapped-drum (Nagel et al, 2001), zymotis packed-bed (Mitchell et al, 2000), gassolid spouted-bed fermenter (Silva and Yang, 1998), horizontal solid state stirred tank reactor (Berovic and Ostroversnik, 1997), vertical cylindrical shaped (Bandelier et al, 1997), cylindrical (Gutierrez-Rojas et al, 1996) fermenters. Advancements have been achieved in refining laboratory-scale processes, yet there remains a need for intensified research on fermenter designs and the scaling-up of processes to faci...…”