L-丙氨酸厌氧发酵关键技术及产业化

传统氨基酸制造主要是通过化学合成或好氧发酵实现。相对于化学合成，微生物发酵可以实现以可再生资源为原料直接生产氨基酸，减少了对石油基原料的依赖，解决了化学合成高污染、高能耗等问题。好氧发酵具有生长快、产量高等特点，但好氧发酵中大量碳源用于细胞生长容易造成糖酸转化率低、能耗高等问题。厌氧发酵是近年来新出现的氨基酸生产模式，具有操作简单、无需通氧、糖酸转化率高容易接近理论最大值等优势。L-丙氨酸是国际上首个实现厌氧发酵产业化生产的氨基酸。本文以L-丙氨酸为例，综述了氨基酸厌氧发酵过程中的关键问题及其在产业化实施中的应用。未来，随着厌氧发酵关键技术在更多化合物生物制造技术中的突破，这种低成本、高效、低碳环保型发酵方式将会带来更大的经济价值和社会效益。

Key technology for anaerobic fermentation of L-alanine and its commercialization

Traditionally, amino acids are produced mainly by chemical synthesis or aerobic fermentation. Compared to chemical synthesis, production of amino acids by microbial fermentation directly uses renewable resources as feedstock and this reduces the dependence on petroleum-based compounds and decreases pollutants generation and toxic substrates usage. Fermentation under aerobic conditions has been used widely for its fast growth and high titers. However, a large amount of carbon is used for cell growth and this results in high biomass but low yield of target chemicals. Unlike the long history of aerobic fermentation, the commercial production of amino acids by anaerobic fermentation is realized only in recent years. It has several advantages such as simpler operation, no need for oxygen supply, and high yield close to the theoretical maximum value. L-alanine is the first amino acid commercially produced by anaerobic fermentation. In this article, we summarize the key technology for anaerobic fermentative production of L-alanine and its commercialization. As it is shown to be low-cost, high-efficiency, and environmental-friendly, anaerobic fermentation is expected to be widely used in industrial process and brings greater economic values and social benefits in the future.