Walls Laura E, Otoupal Peter, Ledesma-Amaro Rodrigo, Velasquez-Orta Sharon B, Gladden John M, Rios-Solis Leonardo
Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH9 3BF, UK; Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, Edinburgh EH9 3BF, UK.
Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, USA; Agile BioFoundry, Department of Energy, Emeryville, CA 94608, USA; Biomaterials and Biomanufacturing Department, Sandia National Laboratories, Livermore, CA 94551, USA.
Bioresour Technol. 2023 Jan;368:128216. doi: 10.1016/j.biortech.2022.128216. Epub 2022 Nov 5.
In this study, organic acids were demonstrated as a promising carbon source for bisabolene production by the non-conventional yeast, Rhodosporidium toruloides, at microscale with a maximum titre of 1055 ± 7 mg/L. A 125-fold scale-up of the optimal process, enhanced bisabolene titres 2.5-fold to 2606 mg/L. Implementation of a pH controlled organic acid feeding strategy at this scale lead to a further threefold improvement in bisabolene titre to 7758 mg/L, the highest reported microbial titre. Finally, a proof-of-concept sequential bioreactor approach was investigated. Firstly, the cellulolytic bacterium Ruminococcus flavefaciens was employed to ferment cellulose, yielding 4.2 g/L of organic acids. R. toruloides was subsequently cultivated in the resulting supernatant, producing 318 ± 22 mg/L of bisabolene. This highlights the feasibility of a sequential bioprocess for the bioconversion of cellulose, into biojet fuel candidates. Future work will focus on enhancing organic acid yields and the use of real lignocellulosic feedstocks to further enhance bisabolene production.
在本研究中，有机酸被证明是一种有前景的碳源，可用于非常规酵母——球拟红酵母在微尺度下生产红没药烯，最高产量为1055±7毫克/升。将最佳工艺放大125倍后，红没药烯产量提高了2.5倍，达到2606毫克/升。在此规模下实施pH控制的有机酸补料策略，使红没药烯产量进一步提高了三倍，达到7758毫克/升，这是已报道的微生物最高产量。最后，研究了一种概念验证的顺序生物反应器方法。首先，采用解纤维瘤胃球菌发酵纤维素，产生4.2克/升的有机酸。随后在所得上清液中培养球拟红酵母，产生318±22毫克/升的红没药烯。这突出了纤维素生物转化为生物喷气燃料候选物的顺序生物过程的可行性。未来的工作将集中在提高有机酸产量以及使用真实的木质纤维素原料以进一步提高红没药烯的产量。
