Miao Liangtian, Li Yin, Zhu Taicheng
CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Bioresour Bioprocess. 2021 Sep 22;8(1):89. doi: 10.1186/s40643-021-00444-9.
β-Alanine (3-aminopropionic acid) is the only naturally occurring β-amino acid and an important precursor for the synthesis of a variety of nitrogen-containing chemicals. Fermentative production of β-alanine from renewable feedstocks such as glucose has attracted significant interest in recent years. Methanol has become an emerging and promising renewable feedstock for biomanufacturing as an alternative to glucose. In this work, we demonstrated the feasibility of β-alanine production from methanol using Pichia pastoris (Komagataella phaffii) as a methylotrophic cell factory. L-Aspartate-α-decarboxylases (ADCs) from different sources were screened and expressed in P. pastoris, followed by the optimization of aspartate decarboxylation by increasing the ADC copy number and C4 precursor supply via the overexpression of aspartate dehydrogenase. The production potential of the best strain was further evaluated in a 1-L fermenter, and a β-alanine titer of 5.6 g/L was obtained. To our best knowledge, this is the highest metabolite production titer ever reached in P. pastoris using methanol as the substrate.
β-丙氨酸（3-氨基丙酸）是唯一天然存在的β-氨基酸，也是合成多种含氮化学品的重要前体。近年来，利用葡萄糖等可再生原料发酵生产β-丙氨酸引起了广泛关注。甲醇作为葡萄糖的替代品，已成为生物制造领域一种新兴且有前景的可再生原料。在本研究中，我们证明了以毕赤酵母（Komagataella phaffii）作为甲基营养型细胞工厂，利用甲醇生产β-丙氨酸的可行性。筛选了来自不同来源的L-天冬氨酸-α-脱羧酶（ADC）并在毕赤酵母中表达，随后通过增加ADC拷贝数和过表达天冬氨酸脱氢酶来优化天冬氨酸脱羧反应，以增加C4前体供应。在1-L发酵罐中进一步评估了最佳菌株的生产潜力，获得了5.6 g/L的β-丙氨酸产量。据我们所知，这是毕赤酵母以甲醇为底物时达到的最高代谢产物产量。
