Abstract Inulin could be converted to bio-based chemicals by an inulinase producer without external inulinase, and the production of 2,3-butanediol was less than 50 g/L. In this work, a novel inulinase producer of Klebsiella pneumoniae H3 was isolated, and inulinase catalytic properties as well as 2,3-butanediol fermentation were investigated. The enzyme was an intracellular inulinase with an optimal pH of 6 ∼ 7 and a temperature of 30 °C. The use of inulin by H3 was dependent on the degree of polymerization (DP), and the average DP of inulin in fermentation broth increased from 2.82 to 8.08 in 24-h culture of batch fermentation. Acidic pretreatment was developed to increase inulin utilization by adjusting medium pH to 3.0 prior to sterilization. In batch fermentation with optimized medium and fermentation conditions, the concentration of target product (2,3-butanediol and acetoin) was 80.4 g/L with a productivity of 2.23 g/(L⋅h), and a yield of 0.426 g/g inulin.

中文翻译：

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新分离的肺炎克雷伯菌产生菊粉酶将菊粉生物转化为 2,3-丁二醇

摘要 菊粉可通过菊粉酶生产者转化为生物基化学品，无需外部菊粉酶，2,3-丁二醇的产量小于50 g/L。在这项工作中，分离出一种新型肺炎克雷伯菌 H3 菊粉酶生产者，并研究了菊粉酶的催化特性以及 2,3-丁二醇发酵。该酶是一种胞内菊粉酶，最适 pH 为 6~7，温度为 30°C。H3对菊粉的使用取决于聚合度（DP），在分批发酵24小时培养中，发酵液中菊粉的平均DP从2.82增加到8.08。通过在灭菌前将培养基 pH 值调整为 3.0，开发了酸性预处理以提高菊粉的利用率。在优化培养基和发酵条件的分批发酵中，