Carboxylic acids contain carboxyl groups that can undergo a wide range of chemical transformation. Therefore, they serve as key platform chemicals for the production of high value-added industrial products. Currently, the majority of carboxylic acid platform chemicals is produced predominantly through traditional chemical synthesis. However, these chemical conversion processes are heavily dependent on fossil fuels and often lead to serious environmental pollution. Recently, the rapid development in metabolic engineering of microbes provide a new and promising alternative route for producing carboxylic acids as platform chemicals. We envision that these bio-based manufacturing processes using microbial cell factories will help move the industrial production of carboxylic acid platform chemicals towards a more sustainable, environmentally friendly and economically competitive direction. While Escherichia coli and Saccharomyces cerevisiae have been the workhorses for biochemical production through metabolic engineering, non-conventional microbes are emerging as suitable hosts for producing carboxylic acids to meet the needs of the industries. Here, we review the employment of metabolic engineering strategies on non-conventional microbes to serve as microbial cell factories for the production of industrially important carboxylic acid platform chemicals.

羧酸包含可以经历广泛化学转化的羧基。因此，它们是生产高附加值工业产品的关键平台化学品。当前，大多数羧酸平台化学品主要通过传统的化学合成方法生产。但是，这些化学转化过程严重依赖化石燃料，并经常导致严重的环境污染。近来，微生物代谢工程学的快速发展为生产羧酸作为平台化学品提供了一种新的有希望的替代途径。我们设想，使用微生物细胞工厂的这些基于生物的制造过程将有助于推动羧酸平台化学品的工业化生产向更加可持续，环保和经济竞争的方向。而大肠杆菌和酿酒酵母已成为通过代谢工程进行生化生产的主力军，非常规微生物正逐渐成为生产羧酸以满足工业需求的合适宿主。在这里，我们回顾了在非常规微生物上代谢工程策略的应用，以作为生产工业上重要的羧酸平台化学品的微生物细胞工厂。