Production of acetic acid from wheat bran by catalysis of an acetoxylan esterase

• DOI: 10.1016/j.biortech.2024.130443
• Publication Date: 2024-02-12T07:07:34Z
• Authors: Mei Li; Hongzhi Tang; Haiyang Hu; Xiaoji Liu; Dongsheng Xue; Xun Yu; Jiaqi Zhang; Hao Chen; Jia Chen; Chongju Wang; Chunjie Gong
• Keywords: Dietary Fiber; Nitrophenols; Butyrates; Esterases; Escherichia coli; Temperature; Catalysis; Acetic Acid

In this study, a gene encoding for acetylxylan esterase was cloned and expressed in E. coli. A single uniform band with molecular weight of 31.2 kDa was observed in SDS-PAGE electrophoresis. Served as the substrate, p-nitrophenol butyrate was employed to detect the recombinant enzyme activity. It exhibited activity at a wide temperature range (30-100 °C) and pH (5.0-9.0) with the optimal temperature of 70 °C and pH 8.0. Acetylxylan esterase showed two substrates' specificities with the highest Vmax of 177.2 U/mg and Km of 20.98 mM against p-nitrophenol butyrate. Meanwhile, the Vmax of p-nitrophenol acetate was 137.0 U/mg and Km 12.16 mM. The acetic acid yield of 0.39 g/g was obtained (70 °C and pH 8.0) from wheat bran pretreated using amylase and papain. This study showed the highest yield up to date and developed a promising strategy for acetic acid production using wheat bran.