L-methionine is an important natural amino acid with broad application prospects. A novel gene encoding the enzyme with the ability to catalyze O-succinyl-L-homoserine (OSH) to L-methionine was screened and characterized. The recombinant O-succinyl-L-homoserine sulfhydrylase from Thioalkalivibrio sulfidiphilus (tsOSHS) exhibited maximum activity at 35 ℃ and pH 6.5. OSHS displayed an excellent thermostability with a half-life of 21.72 h at 30 ℃. Furthermore, the activity of OSHS increased 115% after Fe2+ added. L-methionine was obtained with a total yield reached 42.63 g/L under the concentration of O-succinyl-L-homoserine 400 mM (87.6 g/L). These results indicated that OSHS is a potential candidate for applying in the large-scale bioproduction of L-methionine.

中文翻译：

---

硫代硫代嗜盐菌中O-琥珀酰-L-高丝氨酸巯基化酶的鉴定与表征

L-蛋氨酸是一种重要的天然氨基酸，具有广阔的应用前景。筛选并鉴定了编码该酶的新基因，该酶具有催化O-琥珀酰-L-高丝氨酸（OSH）生成L-蛋氨酸的能力。硫代硫代盐碱弧菌（tsOSHS）的重组O-琥珀酰-L-高丝氨酸巯基化酶在35℃和pH 6.5时表现出最大的活性。OSHS具有出色的热稳定性，在30℃时的半衰期为21.72 h。此外，添加Fe2 +后，OSHS的活性增加了115％。在400 mM（87.6 g / L）的O-琥珀酰-L-高丝氨酸浓度下，获得的L-蛋氨酸的总产量达到42.63 g / L。这些结果表明OSHS是用于大规模生物生产L-蛋氨酸的潜在候选者。