Sustainable Production of Lignocellulolytic Enzymes in Solid-State Fermentation of Agro-Industrial Waste: Application in Pumpkin (Cucurbita maxima) Juice Clarification

Abstract

Valorization of agro-industrial waste through greener and biotechnological processes are promising approaches to minimize the generation of agro-industrial waste. Therefore, the study aimed to produce lignocellulolytic enzymes from agro-industrial waste under solid-state fermentation (SSF) conditions and study their application in the clarification of pumpkin juice. The SSF was performed with three different combinations of wheat bran + rice bran (WBRB), wheat bran + wheat straw (WBWS), and rice bran + wheat straw (RBWS) as dry solid substrates (1:1) using Fusarium oxysporum (MTCC 7229). The protein, carboxymethyl cellulase (CMCase), and xylanase contents ranged from 0.98–3.90 mg/g, 5.89–6.84 U/g substrate, and 10.08–13.77 U/g substrate, respectively in different agro-industrial waste as substrates (WBRB, WBWS, RBWS, and control). The increase in enzyme concentration (0.50–2.40%) added to pumpkin juice exhibited an increased juice yield (16.30–55.60%), reduced browning index (1.03–0.70), and an increase in clarity (5.31–13.77 %T), which was further confirmed by a total variance of 84.83% by principal component analysis. Thus, the low-cost lignocellulolytic enzymes can be produced from agro-industrial waste that might have applications in food and beverage industries. Hence, this approach could be used as a long-term sustainable and circular source to valorize agro-industrial waste towards the greener future and the preservation of ecosystems.

Solid‐state fermentation by Aspergillus niger and Lactobacillus plantarum improved the nutritional and physicochemical properties of wheat bran and whole wheat bread

“…The hardness and chewiness of the dough substituted with SFB were reduced by 28.83% and 35.38%, respectively, compared to that adding RAW bran (Table 1). Fungi could produce lignocellulolytic enzymes during fermentation, thus degrade the water‐insoluble hemicelluloses in the bran and affect the texture properties of bran containing products (Rana et al ., 2021). In addition, the hardness and chewiness of SFB bread were decreased by 75.2% and 92.41%, respectively, compared to the RAW bread, yielding a final product with softer crumb structure (Table 1).…”

“…For instance, Aspergillus niger MUM has been reported to produce ochratoxin A hydrolyzing enzyme during SSF on wheat bran (Abrunhosa et al, 2011). Zearalenone was reported to be reduced by 39.3% in Aspergillus oryzae fermented pennycress meal (Sun et al, 2023a). Co-cultured SSF by Trichoderma reesei and Rhizopus oryzae was capable to lower the concentration of total aflatoxins, zearalenone and deoxynivalenol in corn distiller's dried grains (Sun et al, 2023b).…”

Lignocellulolytic Biocatalysts: The Main Players Involved in Multiple Biotechnological Processes for Biomass Valorization

“…Regarding the substrate, diverse types can be used as carbon sources for lignocellulolytic enzyme production, including seeds, fruits, and agro-industrial residues [ 229 , 231 , 232 , 233 , 234 , 235 , 236 , 237 ]. Since it has low cost and wide availability, the use of agro-industrial residues contributes to reducing the production cost of these enzymes, in addition to not competing with the production of food for human and animal consumption [ 238 ].…”