Zhang Yuxi, Liu Xingyu, Liu Mengqi, Han Lin, Zhao Dandan, Rao Huan, Zhao Xia, Wang Wei, Hao Jianxiong, Liu Xueqiang
College of Food Science and Biology, Hebei University of Science and Technology, No. 26 Yuxiang Street, Shijiazhuang, Hebei 050018, China.
Shijiazhuang Academy of Agriculture and Forestry Sciences, No. 16 Cangxing Street, Shijiazhuang, Hebei 050041, China.
Int J Biol Macromol. 2025 May;310(Pt 1):142860. doi: 10.1016/j.ijbiomac.2025.142860. Epub 2025 Apr 9.
To promote greater gluten matrix development and improve whole wheat bread quality, a novel wheat arabino-xylanase (PcXyn11A) from Podospora comata was extracellularly expressed in Pichia pastoris. The enzymatic activity of the recombinant PcXyn11A reached 727 U/mL at 4.4 mg/mL concentration, following high cell-density fermentation in a 5-L fermenter. The optimal pH and temperature of the purified PcXyn11A were pH 7.5 and 55 °C, respectively. PcXyn11A exhibited a specific activity of 409 U/mg towards wheat arabinoxylan (non-starch polysaccharide). Structural analysis revealed that the Arg155 and Tyr156 residues of PcXyn11A could recognize the arabinose side chain of FAX3, while its Asn157 residue could recognize the ferulic acid side of FAX3 through hydrogen bonds. Moreover, enzymatic modification of whole wheat (WW) dough and bread by PcXyn11A were investigated. PcXyn11A treatment reduced the peak viscosity, final viscosity, and retrogradation value of the WW dough by 3.1 %, 2.2 %, and 2.4 % respectively. Additionally, PcXyn11A treatment decreased the C2, C5, and C5-C4 values of the WW dough by 8.9 %, 5.6 %, and 11.1 %, respectively. These results indicating that PcXyn11A could efficiently degrade wheat arabinoxylan to release water, improve gluten matrix structure, retard retrogradation, increase gas retention, and delay the aging of WW dough. Treatment with 4 mg/kg of PcXyn11A increased the bread volume by 11.45 % and decreased its hardness by 34.68 %, compared to the control. Moreover, the PcXyn11A-treated bread exhibited good anti-aging properties when stored at 4 °C for 1-5 d, with a reduction in hardness by 25.9-35.4 %. This study identified a novel wheat arabino-xylanase (PcXyn11A) that demonstrates excellent non-starch polysaccharide modification to retard retrogradation and improve WW bread quality, laying a solid foundation for its application in flour-based industries.
为促进更大的面筋基质形成并改善全麦面包品质，来自康氏足孢霉的一种新型小麦阿拉伯木聚糖酶（PcXyn11A）在毕赤酵母中进行了胞外表达。在5-L发酵罐中进行高细胞密度发酵后，重组PcXyn11A在浓度为4.4 mg/mL时酶活性达到727 U/mL。纯化后的PcXyn11A的最适pH和温度分别为pH 7.5和55℃。PcXyn11A对小麦阿拉伯木聚糖（非淀粉多糖）的比活性为409 U/mg。结构分析表明，PcXyn11A的Arg155和Tyr156残基可识别FAX3的阿拉伯糖侧链，而其Asn157残基可通过氢键识别FAX3的阿魏酸侧链。此外，还研究了PcXyn11A对全麦（WW）面团和面包的酶促修饰作用。PcXyn11A处理使WW面团的峰值粘度、最终粘度和回生值分别降低了3.1%、2.2%和2.4%。此外，PcXyn11A处理使WW面团的C2、C5和C5-C4值分别降低了8.9%、5.6%和11.1%。这些结果表明，PcXyn11A可有效降解小麦阿拉伯木聚糖以释放水分，改善面筋基质结构,延缓回生，增加气体保留，并延缓WW面团的老化。与对照相比，用4 mg/kg的PcXyn11A处理可使面包体积增加11.45%，硬度降低34.68%。此外，经PcXyn11A处理的面包在4℃下储存1-5天时表现出良好的抗老化性能，硬度降低了25.9-35.4%。本研究鉴定出一种新型小麦阿拉伯木聚糖酶（PcXyn11A），其对非淀粉多糖具有优异的修饰作用，可延缓回生并改善全麦面包品质，为其在面粉工业中的应用奠定了坚实基础。
