Applied Biochemistry and Biotechnology ( IF 3 ) Pub Date : 2020-07-28 , DOI: 10.1007/s12010-020-03368-w Jingjing Li 1 , Chunjing Cao 1, 2 , Yutong Jiang 1 , Qihong Huang 1 , Yulong Shen 1 , Jinfeng Ni 1
β-1,3-glucanases are the main digestive enzymes of plant and fungal cell wall. Transcriptomic analysis of the fungus-growing termite Macrotermes barneyi revealed a high expression of a predicted β-1,3(4)-glucanase (Mbbgl) transcript in termite gut. Here, we described the cDNA cloning, heterologous expression, and enzyme characterization of Mbbgl. Sequence analysis and RT-PCR results showed that Mbbgl is a termite-origin GH16 β-1,3(4)-glucanase. The recombinant enzyme showed the highest activity towards laminarin and was active optimally at 50 °C, pH 5.5. The enzyme displayed endo/exo β-1,3(4)-glucanase activities. Moreover, Mbbgl had weak transglycosylation activity. The results indicate that Mbbgl is an endogenous digestive β-1,3(4)-glucanase, which contributes to the decomposition of plant biomass and fungal hyphae. Additionally, the multiple activities, pH, and ion stabilities make Mbbgl a potential candidate for application in the food industry.
中文翻译:
来自真菌生长白蚁 Macrotermes barneyi 的新型消化 GH16 β-1,3(4)-葡聚糖酶。
β-1,3-葡聚糖酶是植物和真菌细胞壁的主要消化酶。真菌生长白蚁Macrotermes barneyi 的转录组学分析揭示了白蚁肠道中预测的 β-1,3(4)-葡聚糖酶 (Mbbgl) 转录物的高表达。在这里,我们描述了 Mbbgl 的 cDNA 克隆、异源表达和酶表征。序列分析和 RT-PCR 结果表明 Mbbgl 是一种源自白蚁的 GH16 β-1,3(4)-葡聚糖酶。重组酶对海带多糖的活性最高,在 50 °C、pH 5.5 时具有最佳活性。该酶显示出内/外 β-1,3(4)-葡聚糖酶活性。此外,Mbbgl 具有弱的转糖基化活性。结果表明 Mbbgl 是一种内源性消化 β-1,3(4)-葡聚糖酶,有助于植物生物量和真菌菌丝的分解。此外,多种活性、pH 值和离子稳定性使 Mbbgl 成为食品工业应用的潜在候选者。