Research Unit in Bioconversion/Bioseparation for Value-Added Chemical Production, Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand.
Department of Molecular Microbiology, Faculty of Life Science, Tokyo University of Agriculture, Sakuragaoka, Tokyo, 156-8502, Japan.
Arch Microbiol. 2021 Aug;203(6):3577-3590. doi: 10.1007/s00203-021-02352-0. Epub 2021 May 7.
Recently, the industrial-scale development of microbial D-lactic acid production has been discussed. In this study, the efficiency of the new isolate Sporolactobacillus terrae SBT-1 for producing D-lactic acid under challenge conditions was investigated. The isolate SBT-1 exhibited superior activity in fermenting a very high glucose or sucrose concentration to D-lactic acid compared to the other S. terrae isolates previously reported in the literature; therefore, SBT-1 could overcome the limitations of effective lactic acid production. In batch cultivation using 360 g/L glucose, SBT-1 produced 290.30 g/L D-lactate with a sufficiently high glucose conversion yield of 86%, volumetric productivity of 3.02 g/L h, and optical purity of 96.80% enantiomer excess. SBT-1 could also effectively utilize 440 g/L sucrose as a sole carbon source to produce 276.50 g/L lactic acid with a conversion yield of 90%, a production rate of 2.88 g/L h, and an optical purity of 98%. D-Lactic acid fermentation by two other related producers, S. inulinus NRIC1133 and S. terrae NRIC0357, was compared with fermentation by isolate SBT-1. The experimental data revealed that SBT-1 possessed the ability to ferment relatively high glucose or sucrose concentrations to D-lactic acid without obvious catabolite repression and byproduct formation compared to the two reference strains. In draft genome sequencing of S. terrae SBT-1, the results provided here can promote further study to overcome the current limitations for the industrial-scale production of D-lactic acid.
最近，人们讨论了微生物 D-乳酸的工业规模生产。在本研究中，研究了新分离的地衣芽孢杆菌 SBT-1 在挑战性条件下生产 D-乳酸的效率。与以前文献中报道的其他地衣芽孢杆菌分离株相比，该分离株 SBT-1 在发酵非常高的葡萄糖或蔗糖浓度为 D-乳酸方面表现出更高的活性；因此，SBT-1 可以克服有效生产乳酸的限制。在使用 360g/L 葡萄糖的分批培养中，SBT-1 产生了 290.30g/L 的 D-乳酸，葡萄糖转化率高达 86%，体积生产率为 3.02g/L/h，光学纯度为 96.80%对映体过量。SBT-1 还可以有效地利用 440g/L 蔗糖作为唯一碳源生产 276.50g/L 乳酸，转化率为 90%，生产速率为 2.88g/L/h，光学纯度为 98%。与两种相关生产者 S. inulinus NRIC1133 和 S. terrae NRIC0357 的 D-乳酸发酵相比，对分离株 SBT-1 的发酵进行了比较。实验数据表明，与两个参考菌株相比，SBT-1 具有在没有明显分解代谢物抑制和副产物形成的情况下发酵相对较高浓度的葡萄糖或蔗糖生产 D-乳酸的能力。在对地衣芽孢杆菌 SBT-1 的草图基因组测序中，提供的结果可以促进进一步的研究，以克服当前 D-乳酸工业生产的限制。
