Azzouz Zahra, Bettache Azzeddine, Boucherba Nawel, Prieto Alicia, Martinez Maria Jesus, Benallaoua Said, de Eugenio Laura Isabel
Laboratoire de Microbiologie Appliquée (LMA), Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, 06000 Bejaia, Algeria.
Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas (CIB-CSIC), C/Ramiro de Maeztu 9, 28040 Madrid, Spain.
Molecules. 2021 Apr 26;26(9):2527. doi: 10.3390/molecules26092527.
Plant biomass constitutes the main source of renewable carbon on the planet. Its valorization has traditionally been focused on the use of cellulose, although hemicellulose is the second most abundant group of polysaccharides on Earth. The main enzymes involved in plant biomass degradation are glycosyl hydrolases, and filamentous fungi are good producers of these enzymes. In this study, a new strain of was used for hemicellulase production under solid-state fermentation using wheat straw as single-carbon source. Physicochemical parameters for the production of an endoxylanase were optimized by using a One-Factor-at-a-Time (OFAT) approach and response surface methodology (RSM). Maximum xylanase yield after RSM optimization was increased 3-fold, and 1.41- fold purification was achieved after ultrafiltration and ion-exchange chromatography, with about 6.2% yield. The highest activity of the purified xylanase was observed at 50 °C and pH 6. The enzyme displayed high thermal and pH stability, with more than 90% residual activity between pH 3.0-9.0 and between 30-40 °C, after 24 h of incubation, with half-lives of 30 min at 50 and 60 °C. The enzyme was mostly active against wheat arabinoxylan, and its kinetic parameters were analyzed ( = 26.06 mg·mL and = 5.647 U·mg). Wheat straw xylan hydrolysis with the purified β-1,4 endoxylanase showed that it was able to release xylooligosaccharides, making it suitable for different applications in food technology.
植物生物质是地球上可再生碳的主要来源。传统上，其价值转化主要集中在纤维素的利用上，尽管半纤维素是地球上第二丰富的多糖类群。参与植物生物质降解的主要酶是糖基水解酶，丝状真菌是这些酶的良好生产者。在本研究中，使用一种新的菌株在固态发酵条件下以小麦秸秆作为单一碳源生产半纤维素酶。采用一次单因素法（OFAT）和响应面法（RSM）对木聚糖内切酶生产的理化参数进行了优化。经RSM优化后，木聚糖酶的最大产量提高了3倍，经过超滤和离子交换色谱后实现了1.41倍的纯化，产率约为6.2%。纯化后的木聚糖酶在50℃和pH 6时表现出最高活性。该酶具有较高的热稳定性和pH稳定性，在pH 3.0 - 9.0以及30 - 40℃之间孵育24小时后，残留活性超过90%，在50℃和60℃下的半衰期为30分钟。该酶对小麦阿拉伯木聚糖的活性最强，并对其动力学参数进行了分析（ = 26.06 mg·mL和 = 5.647 U·mg）。用纯化的β - 1,4木聚糖内切酶对小麦秸秆木聚糖进行水解表明，它能够释放低聚木糖，使其适用于食品技术中的不同应用。
