To identify and characterize a new β-agarase from Cellulophaga omnivescoria W5C capable of producing biologically-active neoagarooligosaccharides from agar. The β-agarase, Aga1, has signal peptides on both N- and C-terminals, which are involved in the type IX secretion system. It shares 75% protein sequence identity with AgaD from Zobellia galactanivorans and has a molecular weight of 54 kDa. Biochemical characterization reveals optimum agarolytic activities at pH 7–8 and temperature 30–45 °C. Aga1 retains at least 33% activity at temperatures lower than the sol–gel transition state of agarose. Metal ions are generally not essential, but calcium and potassium enhance its activity whereas iron and zinc are inhibitory. Finally, hydrolysis of agarose with Aga1 yields neoagarotetraose, neoagarohexaose, and neoagarooctaose. Aga1 displays unique traits such as moderate psychrophilicity, stability, and synergy with other agarases, which makes it an excellent candidate for biosynthetic production of neoagarooligosaccharides from agar.

中文翻译：

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来自 Cellulophaga omnivescoria W5C 的新型 GH16 β-琼脂酶 (Aga1) 的过表达和表征

鉴定和表征来自 Cellulophaga omnivescoria W5C 的新型 β-琼脂酶，该酶能够从琼脂中产生具有生物活性的新琼脂低聚糖。β-琼脂酶 Aga1 在 N 端和 C 端都有信号肽，它们参与 IX 型分泌系统。它与来自 Zobellia galactanivorans 的 AgaD 具有 75% 的蛋白质序列同一性，分子量为 54 kDa。生化表征揭示了在 pH 7-8 和温度 30-45 °C 下的最佳琼脂溶解活性。Aga1 在低于琼脂糖溶胶-凝胶过渡态的温度下保留至少 33% 的活性。金属离子通常不是必需的，但钙和钾可增强其活性，而铁和锌则具有抑制作用。最后，用 Aga1 水解琼脂糖会产生新琼脂四糖、新琼脂六糖和新琼脂八糖。