This study aims to use neutral pH optimum arginase as the catalyst for high-efficiency l-ornithine production. Sulfobacillus acidophilus arginase was firstly cloned and overexpressed in Escherichia coli. The purified enzyme was obtained, and the molecular mass determination showed that this arginase was a hexamer. S. acidophilus arginase possessed similarities with the other arginases such as the conserved sequences, purification behavior, and the necessity for Mn²⁺ as a cofactor. The maximum enzyme activity was obtained at pH 7.5 and 70 °C. Thermostability and pH stability analysis showed that the arginase was stable at 30–60 °C and pH 7.0–8.5, respectively. The kinetic parameters suggested that S. acidophilus arginase could efficiently hydrolyze l-arginine. Bioconversion with this neutral pH optimum arginase had the advantages of avoiding producing by-product, high molar yield, and high-level production of l-ornithine. When the bioconversion was performed with a fed-batch strategy and a coupled-enzyme system involving S. acidophilus arginase and Jack bean urease, the final production of 2.87 mol/L was obtained with only 1.72 mmol/L l-arginine residue, and the molar yield was 99.9%. The highest production record suggests that S. acidophilus arginase has a great prospect in industrial l-ornithine production.

本研究旨在使用中性pH最适精氨酸酶作为催化剂用于高效率升鸟氨酸的生产。嗜酸硫杆菌精氨酸酶首先被克隆并在大肠杆菌中过表达。获得纯化的酶，并且分子量测定表明该精氨酸酶为六聚体。嗜酸链球菌精氨酸酶与其他精氨酸酶具有相似性，如保守序列，纯化行为和以Mn ²⁺作为辅因子的必要性。在pH 7.5和70°C下获得最大的酶活性。热稳定性和pH稳定性分析表明，精氨酸酶分别在30–60°C和pH 7.0–8.5下稳定。动力学参数表明嗜酸链球菌精氨酸酶可以有效地水解1-精氨酸。用该中性pH最佳精氨酸酶进行生物转化具有避免产生副产物，高摩尔产率和高产量生产1-鸟氨酸的优点。当采用补料分批策略和涉及嗜酸链球菌精氨酸酶和杰克豆脲酶的偶联酶系统进行生物转化时，最终产量为2.87 mol / L，仅残留1.72 mmol / L 1-精氨酸，摩尔产率为99.9％。最高的生产记录表明，S.嗜酸精氨酸酶在工业巨大的应用前景升鸟氨酸生产。