Research and Development Center, GS Caltex Corporation, Yuseong-gu, Daejeon, 34122, Republic of Korea.
J Ind Microbiol Biotechnol. 2020 Jan;47(1):97-108. doi: 10.1007/s10295-019-02249-4. Epub 2019 Nov 22.
Several microorganisms can produce 2,3-butanediol (BDO), an industrially promising chemical. In this study, a Bacillus licheniformis named as 4071, was isolated from soil sample. It is a GRAS (generally recognized as safe) strain and could over-produce 2,3-BDO. Due to its mucoid forming characteristics, UV-random mutagenesis was carried out to obtain a mucoid-free strain, 4071-15. As a result, capabilities of 4071-15 strain in terms of transformation efficiency of bacillus plasmids (pC194, pUB110, and pUCB129) and fermentation performance were highly upgraded compared to those of the parent strain. In particular, 4071-15 strain could produce 123 g/L of 2,3-BDO in a fed-batch fermentation in which the ratio of (2R,3S)- to (2R,3R)-form isomers was 1:1. To increase the selectivity of (2R,3R)-BDO, budC gene was deleted by using temperature-sensitive gene deletion process via homologous recombination. The 4071-15 △budC mutant strain dramatically increased selectivity of (2R,3R)-BDO to 91% [96.3 g/L of (2R,3R)-BDO and 9.33 g/L of (2R,3S)-BDO], which was 43% higher than that obtained by the parent strain. This study has shown the potential of an isolate for 2,3-BDO production, and that the ratio of 2,3-BDO can be controlled by genetic engineering depending on its industrial usage.
几种微生物可以产生 2,3-丁二醇（BDO），这是一种有工业应用前景的化学品。在这项研究中，从土壤样本中分离出一株名为 4071 的地衣芽孢杆菌。它是一种 GRAS（通常被认为是安全的）菌株，可以过量生产 2,3-BDO。由于其黏液形成的特点，我们对其进行了紫外线随机诱变，得到了一株无黏液的突变株 4071-15。结果表明，与亲本菌株相比，4071-15 菌株在芽孢杆菌质粒（pC194、pUB110 和 pUCB129）的转化效率和发酵性能方面具有更高的能力。特别是，4071-15 菌株可以在分批补料发酵中生产 123 g/L 的 2,3-BDO，（2R,3S）-和（2R,3R）-异构体的比例为 1:1。为了提高（2R,3R）-BDO 的选择性，我们通过同源重组的温度敏感基因缺失过程删除了 budC 基因。4071-15 △budC 突变株显著提高了（2R,3R）-BDO 的选择性，达到 91%[96.3 g/L 的（2R,3R）-BDO 和 9.33 g/L 的（2R,3S）-BDO]，比亲本菌株提高了 43%。这项研究表明了一种用于 2,3-BDO 生产的分离株的潜力，并且可以根据其工业用途通过基因工程控制 2,3-BDO 的比例。
