Bioproduction of N-acetyl-d-glucosamine (GlcNAc) from chitin, the second most abundant natural renewable polymer on earth, is of great value in which chitinolytic enzymes play key roles. In this study, a novel glycoside hydrolase family-18 β-N-acetylglucosaminidase (PbNag39) from Paenibacillus barengoltzii suitable for GlcNAc production was identified and biochemically characterized. It possessed a unique shallow catalytic groove (5.8 Å) as well as a smaller C-terminal domain (solvent-accessible surface area, 5.1 × 103 Å2) and exhibited strict substrate specificity toward N-acetyl chitooligosaccharides (COS) with GlcNAc as the sole product, showing a typical manner of action of β-N-acetylglucosaminidases. Thus, an environmentally friendly bioprocess for GlcNAc production from ball-milled powdery chitin by an enzyme cocktail reaction was further developed. By using the new route, the powdery chitin conversion rate increased from 23.3% (v/v) to 75.3% with a final GlcNAc content of 22.6 mg mL-1. The efficient and environmentally friendly bioprocess may have great application potential in GlcNAc production.

中文翻译：

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来自巴氏芽孢杆菌的β-N-乙酰氨基葡萄糖苷酶的生化特征和结构分析，用于高效生产N-乙酰-d-氨基葡萄糖。

由几丁质（地球上第二大天然可再生聚合物）的生物生产N-乙酰基-d-葡萄糖胺（GlcNAc）具有巨大的价值，其中几丁质分解酶起着关键作用。在这项研究中，鉴定了适用于GlcNAc生产的来自巴氏芽孢杆菌的新颖的糖苷水解酶家族-18β-N-乙酰氨基葡糖苷酶（PbNag39），并对其进行了生化表征。它具有独特的浅催化槽（5.8Å）和较小的C末端结构域（溶剂可及的表面积5.1×103Å2），并以GlcNAc为唯一底物对N-乙酰基寡糖（COS）表现出严格的底物特异性。产物，显示出β-N-乙酰氨基葡萄糖苷酶的典型作用方式。从而，进一步开发了一种环境友好的生物工艺，该工艺通过酶鸡尾酒反应从球磨粉状甲壳素生产GlcNAc。通过使用新途径，粉末状几丁质转化率从23.3％（v / v）增加到75.3％，最终GlcNAc含量为22.6 mg mL-1。高效，环保的生物工艺可能在GlcNAc生产中具有巨大的应用潜力。