BACKGROUND Tobacco stalk (TS), a major agricultural waste abundant in pectin, has resulted in concerns about the need for its reuse. The nicotine in TS is considered a chemical that is to\xic and hazardous to the environment. RESULTS In this study, Bacillus tequilensis CAS-MEI-2-33 was isolated from cigar wrappers to produce alkaline pectinase using TS. Subsequently, the medium and fermentation conditions for the production of pectinase by B. tequilensis CAS-MEI-2-33 were optimized. The optimal fermentation period, pH of the initial fermentation medium, concentration of TS, and inoculum amount for B. tequilensis CAS-MEI-2-33 were 40 h, 40 g/L, 7.0, and 3%, respectively. Under optimal conditions, the pectinase activity was 1370 U/mL. Then, the enzymatic properties, such as the optimum pH, reaction temperature, temperature stability, and effects of metal ions, were studied. The optimal pH was determined to be 10.0, indicating that the enzyme was an alkaline pectinase. The optimal temperature was 40 °C, and pectinase activity was stable at 40 °C. The Ag+ metal ions were shown to remarkably promote enzyme activity. The pectinase was partly purified by ammonium sulfate precipitation, ion exchange chromatography, and Sephacryl S-100 chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and LC-MS/MS analyses were utilized to analyze the pectinase. CONCLUSIONS This study provided a new alkaline pectinase candidate and a new strategy for the use of TS.

中文翻译：

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碱性果胶酶的生产：利用新分离菌株特奎伦芽孢杆菌 CAS-MEI-2-33 调查烟草秆用途的案例研究。


背景技术烟秆(TS)是一种富含果胶的主要农业废物，引起了对其再利用需求的担忧。 TS 中的尼古丁被认为是一种有毒且对环境有害的化学物质。结果在本研究中，从雪茄茄衣中分离出特奎拉芽孢杆菌 CAS-MEI-2-33，利用 TS 生产碱性果胶酶。随后对B. tequilensis CAS-MEI-2-33生产果胶酶的培养基和发酵条件进行了优化。 B. tequilensis CAS-MEI-2-33的最佳发酵时间、初始发酵培养基pH、TS浓度和接种量分别为40 h、40 g/L、7.0和3%。在最佳条件下，果胶酶活性为1370 U/mL。然后，研究了酶的性质，如最适pH、反应温度、温度稳定性和金属离子的影响。确定该酶的最适pH为10.0，表明该酶为碱性果胶酶。最适温度为40℃，40℃时果胶酶活性稳定。 Ag+金属离子显示出显着促进酶活性。通过硫酸铵沉淀、离子交换色谱法和Sephacryl S-100色谱法部分纯化果胶酶。利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳 (SDS-PAGE) 和 LC-MS/MS 分析来分析果胶酶。结论 本研究提供了一种新的碱性果胶酶候选物和 TS 使用的新策略。