Halophilic bacteria are well known to produce highly salt-tolerant enzymes that have unusual applications in biotechnology. Production of halophilic proteins is generally not expected in mesohaline microorganisms. Ulkenia sp. AH-2, a mesohaline, marine straminipilan thraustochytrid isolated from waters of a mangrove ecosystem, produces halophilic alpha-amylases. Four enzyme fractions, viz.., A, B, C, and D, were obtained upon ammonium sulfate fractionation and gel filtration. These had a broad salinity tolerance ranging from 0 to 4 M NaCl, with an optimum at 3 M NaCl. Pools A, C, and D each resolved as a single band on PAGE and zymogram analysis, and the purified proteins were designated Amy a, Amy c, and Amy h. The major activity resided in “pool B,” consisting of several amylases which could not be further resolved into pure fractions. Together, these had an optimum at 2 M NaCl. All the enzymes were stable to storage for 2 to 24 h at 4 °C in a range of salt concentrations and even showed enhanced activity following such incubations. True to halophilic enzymes, the complex of “pool B” amylases showed improved activity in the presence of a wide range of organic solvents at 20% concentration. These enzymes are of particular interest by virtue of their constitutive nature as well as production under culture conditions that do not require salinity beyond that of seawater.

中文翻译：

---

Mesohaline破囊壶菌产生极端嗜盐的α-淀粉酶。

众所周知，嗜盐细菌会产生高度耐盐的酶，这些酶在生物技术中具有非凡的应用。通常在中盐微生物中不期望产生嗜盐蛋白。Ulkenia sp。AH-2是一种从红树林生态系统的水域中分离出来的中盐类海洋藻类超细囊藻囊藻，可产生嗜盐的α-淀粉酶。通过硫酸铵分级分离和凝胶过滤获得四种酶级分，即A，B，C和D。这些具有宽泛的盐度耐受性，范围为0至4 M NaCl，最佳为3 M NaCl。池A，C和D在PAGE和酶谱分析中均解析为一条带，纯化的蛋白分别命名为Amy a，Amy c和Amy h。主要活性存在于“池B”中，该池由几种淀粉酶组成，无法进一步分解为纯馏分。总之，它们在2 M NaCl中具有最佳值。所有酶在一定盐浓度范围内均可在4°C下稳定保存2至24小时，甚至在此类孵育后显示出增强的活性。对嗜盐酶而言，“池B”淀粉酶的复合物在存在20％浓度的各种有机溶剂的情况下显示出改善的活性。这些酶由于其组成性质以及在不需要盐度超过海水的盐分的培养条件下的生产而特别受关注。