Microbial proteases are widely used as commercial enzymes, which have an active role in several industrial processes. The aim of this study was to investigate the production and properties of extracellular proteases from Barrientosiimonas sp. strain V9. The cultivation conditions for protease production were studied using different carbon and nitrogen sources. Maximum protease production was obtained in medium containing 25 g L-1 sucrose, 7 g L-1 KNO3, and initial pH 7.0 at 35 °C and 150 rpm during 72 h. Under these conditions, maximum proteolytic activity reached 1200 U mL-1. The enzyme extract showed optimum activity at 60 °C, pH 9.0, and was stable from 30 to 50 °C within a pH range from 4.0 to 10.0 and NaCl concentration up to 2.5 M. The enzyme was stable in the presence of EDTA, urea, Triton X-100 and laundry detergent (sodium lauryl sulfate as main component). The addition of 1% sodium dodecyl sulfate, Tween-80, or Tween-20 increased the activity by 183% and 119% respectively, while 2-mercaptoethanol reduced the activity to 71%. Casein zymogram analysis revealed three hydrolysis zones suggesting that Barrientosiimonas sp. V9 expresses proteases with molecular weights about 60, 45, and 35 kDa, which were inhibited in the presence of phenylmethylsulfonyl fluoride. Barrientosiimonas sp. V9 produces halotolerant serine proteases with great biotechnological potential.

中文翻译：

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从一种新的酶源，Barrientosiimonas sp。生产和表征极端嗜热蛋白酶。V9。

微生物蛋白酶被广泛用作商业酶，其在几种工业过程中具有积极作用。这项研究的目的是调查Barrientosiimonas sp。的细胞外蛋白酶的生产和性质。菌株V9。研究了使用不同碳源和氮源生产蛋白酶的培养条件。在含有25 g L-1蔗糖，7 g L-1 KNO3和初始pH 7.0的培养基中，于35°C和150 rpm下72小时内可获得最大的蛋白酶产量。在这些条件下，最大的蛋白水解活性达到1200 U mL-1。该酶提取物在60°C，pH 9.0时表现出最佳活性，并且在pH范围4.0至10.0和NaCl浓度高达2.5 M的情况下在30至50°C时稳定。在EDTA，尿素存在下，该酶是稳定的，Triton X-100和洗衣粉（十二烷基硫酸钠为主要成分）。加入1％十二烷基硫酸钠，Tween-80或Tween-20分别将活性提高183％和119％，而2-巯基乙醇则将活性降低到71％。酪蛋白酶谱分析揭示了三个水解区，表明Barrientosiimonas sp。V9表达分子量约为60、45和35 kDa的蛋白酶，这些蛋白酶在苯基甲基磺酰氟的存在下被抑制。Barrientosiimonas sp。V9产生具有巨大生物技术潜力的卤代丝氨酸丝氨酸蛋白酶。酪蛋白酶谱分析揭示了三个水解区，表明Barrientosiimonas sp。V9表达分子量约为60、45和35 kDa的蛋白酶，这些蛋白酶在苯基甲基磺酰氟的存在下被抑制。Barrientosiimonas sp。V9产生具有巨大生物技术潜力的卤代丝氨酸丝氨酸蛋白酶。酪蛋白酶谱分析揭示了三个水解区，表明Barrientosiimonas sp。V9表达分子量约为60、45和35 kDa的蛋白酶，这些蛋白酶在苯基甲基磺酰氟的存在下被抑制。Barrientosiimonas sp。V9产生具有巨大生物技术潜力的卤代丝氨酸丝氨酸蛋白酶。