Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Gent, Belgium.
BIOMATH, Department of Mathematical Modelling, Statistics and Bioinformatics, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Gent, Belgium.
Sci Rep. 2018 Jun 27;8(1):9724. doi: 10.1038/s41598-018-27594-9.
Hexanoic acid (HA), also called caproic acid, can be used as an antimicrobial agent and as a precursor to various chemicals, such as fuels, solvents and fragrances. HA can be produced from ethanol and acetate by the mesophilic anaerobic bacterium Clostridium kluyveri, via two successive elongation steps over butyrate. A high-throughput anaerobic growth curve technique was coupled to a data analysis framework to assess growth kinetics for a range of substrate and product concentrations. Using this method, growth rates and several kinetic parameters were determined for C. kluyveri. A maximum growth rate (µ) of 0.24 ± 0.01 h was found, with a half-saturation index for acetic acid (K) of 3.8 ± 0.9 mM. Inhibition by butyric acid occurred at of 124.7 ± 5.7 mM (K), while the final product, HA, linearly inhibited growth with complete inhibition above 91.3 ± 10.8 mM (K of 10.910 ± 1.310 mM) at pH = 7, indicating that the hexanoate anion also exerts toxicity. These parameters were used to create a dynamic mass-balance model for bioproduction of HA. By coupling data collection and analysis to this modelling framework, we have produced a powerful tool to assess the kinetics of anaerobic micro-organisms, demonstrated here with C. kluyveri, in order further explore the potential of micro-organisms for chemicals production.
己酸（HA），也称为正己酸，可以用作抗菌剂和各种化学品的前体，如燃料、溶剂和香料。HA 可以通过嗜温厌氧细菌克鲁维氏梭菌（Clostridium kluyveri）从乙醇和醋酸盐生产，通过丁酸的两个连续伸长步骤。高通量厌氧生长曲线技术与数据分析框架相结合，评估了一系列基质和产物浓度下的生长动力学。使用这种方法，确定了 C. kluyveri 的生长速率和几个动力学参数。发现最大生长速率（µ）为 0.24±0.01 h，醋酸的半饱和指数（K）为 3.8±0.9 mM。丁酸的抑制作用发生在 124.7±5.7 mM（K），而最终产物 HA 以线性方式抑制生长，在 pH=7 时，高于 91.3±10.8 mM（K of 10.910±1.310 mM）完全抑制生长，表明己酸根阴离子也具有毒性。这些参数用于创建 HA 生物生产的动态质量平衡模型。通过将数据收集和分析与该建模框架相结合，我们已经创建了一种强大的工具，用于评估厌氧微生物的动力学，这里以 C. kluyveri 为例，以进一步探索微生物在化学品生产中的潜力。
