Facultad de Ciencias Químicas. Universidad Autonoma de Coahuila, Unidad Saltillo, Saltillo, Coahuila, 25280, Mexico.
Facultad de Ciencias Biológicas. Universidad Autonoma de Coahuila, Unidad Torreón, Torreón, Coahuila, 27000, Mexico.
J Environ Manage. 2023 Dec 1;347:119067. doi: 10.1016/j.jenvman.2023.119067. Epub 2023 Sep 29.
In the pursuit of sustainability, managing agro-industrial and food processing residues (AFR) efficiently is crucial. This study proposes a systematic approach to convert AFR into valuable products via solid-state fermentation (SSF). Using fungal enzyme production as a case study, this adaptable methodology suits any SSF bioprocess. Initially, AFR's physicochemical properties were evaluated to assess their feasible use as carbon sources and solid matrices for SSF. Then, five strains were screened for their capability to produce enzymes (Xylanase, X; pectinase, P; cellulase, C). Apple pomace (AP) and brewery spent grain (BSG) with Aspergillus sp. (strain G5) were selected. Subsequent steps involved a two-phase statistical approach, identifying critical factors and optimizing them. Process conditions were screened using a Plackett-Burman design, narrowing critical variables to three (BSG/AP, pH, humidity). Response Surface Methodology (Central Composite Design) further optimized these factors for co-synthesis of X, P, and C. The humidity had the most significant effect on the three responses. The optimum conditions depended on each enzyme and were further validated to maximize either X, P or C. The obtained extracts were used for pectin extraction from orange peels. The extract containing primarily xylanase (X = 582.39, P = 22.86, C = 26.10 U mL) showed major pectin yield recovery (12.33 ± 0.53%) and it was obtained using the optimal settings of BSG/AP (81/19), humidity (50.40%), and pH (4.58). The findings will enable adjusting process conditions to obtain enzymatic cocktails with a tailored composition for specific applications.
在追求可持续性的过程中，有效地管理农业工业和食品加工残渣（AFR）至关重要。本研究提出了一种通过固态发酵（SSF）将 AFR 转化为有价值产品的系统方法。以真菌酶生产为例，这种适应性强的方法适用于任何 SSF 生物工艺。首先，评估 AFR 的物理化学性质，以评估其作为 SSF 的碳源和固体基质的可行性。然后，筛选了 5 株菌，以评估它们生产酶（木聚糖酶，X；果胶酶，P；纤维素酶，C）的能力。选择了苹果渣（AP）和啤酒糟（BSG）与 Aspergillus sp.（菌株 G5）进行固态发酵。接下来的步骤包括使用两阶段统计方法，确定关键因素并对其进行优化。使用 Plackett-Burman 设计筛选工艺条件，将关键变量缩小到三个（BSG/AP、pH 值、湿度）。响应面法（中心复合设计）进一步优化了这些因素，以协同合成 X、P 和 C。湿度对三个响应的影响最大。最佳条件取决于每种酶，并进一步验证以最大限度地提高 X、P 或 C 的产量。获得的提取物用于从橙皮中提取果胶。主要含有木聚糖酶（X = 582.39、P = 22.86、C = 26.10 U mL）的提取物显示出主要的果胶回收率（12.33 ± 0.53%），并使用 BSG/AP（81/19）、湿度（50.40%）和 pH（4.58）的最佳设置获得。这些发现将使我们能够调整工艺条件，以获得具有特定应用所需的定制组成的酶混合物。
