Laboratory of Bioprocess Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, India.
Department of Biotechnology, Central University of Haryana, Mahendergarh, India.
Prep Biochem Biotechnol. 2022;52(2):197-209. doi: 10.1080/10826068.2021.1925911. Epub 2021 May 19.
Production of cellulolytic and xylanolytic enzymes by was enhanced using response surface methodology in solid-state fermentation (SSF) using wheat straw and cotton oil cake. Cellulolytic and xylanolytic enzymes were partially purified by ammonium sulfate precipitation followed by ion exchange and gel filtration chromatographic techniques. Xylanase of is neutral xylanase displaying optimal activity at 60 °C with and values of 0.2 mg/mL and 238.05 µmole/min, respectively. All cellulases produced by the thermophilic mold showed optimal activity at pH 5.0 and 60 °C with values of 0.312 mg/mL, 0.113 mg/mL, and 0.285 mM for carboxymethyl cellulase (CMCase), filter paper cellulase (FPase), and β-glucosidase, respectively and while values were 181.81, 138.88, and 66.67 µmole/min, respectively. The presence of various metal ions (Ca and Co), chemical reagent (glutaraldehyde), and surfactants (Tween 80 and Triton X-100) significantly improved the activities of all enzymes. All the enzymes showed high storage stability under low temperature (-20 and 4 °C) conditions. Cellulolytic and xylanolytic enzymes resulted in enhanced liberation of reducing sugars (356.34 mg/g) by hydrolyzing both cellulosic and hemicellulosic fractions of ammonia-pretreated rice straw as compared to other pretreatment methods used in the study. Fermentation of enzymatic hydrolysate resulted in the formation of 28.88 and 27.18 g/L of bioethanol in separate hydrolysis and fermentation (SHF) process by and , respectively. Therefore, cellulolytic and xylanolytic enzymes of exhibited ideal properties of biocatalysts useful in the saccharification of cellulosic and hemicellulosic fractions of rice straw for the production of bioethanol.
利用响应面法（RSM）在固态发酵（SSF）中，以小麦秸秆和棉籽油饼为原料，提高了 的纤维素酶和木聚糖酶的产量。通过硫酸铵沉淀、离子交换和凝胶过滤色谱技术对纤维素酶和木聚糖酶进行了部分纯化。 的木聚糖酶为中性木聚糖酶，在 60°C 时活性最佳， 值和 分别为 0.2mg/mL 和 238.05 µmole/min。该嗜热真菌产生的所有纤维素酶在 pH 5.0 和 60°C 时活性最佳，羧甲基纤维素酶（CMCase）、滤纸纤维素酶（FPase）和 β-葡萄糖苷酶的 值分别为 0.312mg/mL、0.113mg/mL 和 0.285mM，而 值分别为 181.81、138.88 和 66.67 µmole/min。各种金属离子（Ca 和 Co）、化学试剂（戊二醛）和表面活性剂（Tween 80 和 Triton X-100）的存在显著提高了所有酶的活性。所有酶在低温（-20 和 4°C）条件下均具有较高的储存稳定性。与研究中使用的其他预处理方法相比，纤维素酶和木聚糖酶通过水解氨预处理稻秸的纤维素和半纤维素部分，可显著提高还原糖的释放量（356.34mg/g）。酶水解物的发酵导致 和 分别在单独的水解和发酵（SHF）过程中形成 28.88 和 27.18g/L 的生物乙醇。因此， 产生的纤维素酶和木聚糖酶具有理想的生物催化剂特性，可用于稻秸的纤维素和半纤维素部分的糖化，以生产生物乙醇。
