1.
Current challenges facing one-step production of l-ascorbic acid.
Wang, P, Zeng, W, Xu, S, Du, G, Zhou, J, Chen, J
Biotechnology advances. 2018;(7):1882-1899
Abstract
l-ascorbic acid (L-AA, vitamin C) is an essential vitamin that is widely used as a nutrient or medicine in the pharmaceuticals, cosmetics, food, beverage and feed additive industries, and accounts for the largest share of the global vitamins market. L-AA is mainly produced by a classic two-step fermentation process that suffers from the use of a multi-step mixed culture system and two rounds of sterilisation, which significantly increases the cost of the final product. One-step fermentation has been attempted, but a method rivalling the efficiency of the two-step process has not yet been achieved on an industrial scale. In this review, based on the current classical two-step fermentation processes and other potential routes for L-AA production, the challenges and pitfalls of a one-step fermentation process are summarised. The prospects for one-step fermentation production of L-AA and how this might be achieved are also discussed.
2.
Structure, mechanism and regulation of an artificial microbial ecosystem for vitamin C production.
Zou, W, Liu, L, Chen, J
Critical reviews in microbiology. 2013;(3):247-55
Abstract
At present, the modern two-step fermentation process is one of the major approaches for the industrial production of vitamin C. The key step in this process is the conversion of L-sorbose to 2-keto-L-gulonic acid (2-KLG), the vitamin C precursor, which is accomplished by an artificial microbial ecosystem consisting of Ketogulonicigenium vulgare and Bacillus megaterium. This review describes current progress in understanding this ecosystem, not only the individual physiological characteristics of the two strains, but also the interactions between them. Special emphasis is placed on recent systems biology studies of the ecosystem. We also discuss the regulation and improvement of this ecosystem, including analysis of the fermentation medium components and genetic engineering and optimum fermentative strategies. Finally, perspectives on the knowledge and engineering of this important artificial microbial ecosystem are discussed.
3.
Metabolic engineering of microorganisms for vitamin C production.
Zhou, J, Du, G, Chen, J
Sub-cellular biochemistry. 2012;:241-59
Abstract
Vitamin C, an important organic acid, is widely used in the industries of pharmaceuticals, cosmetics, food, beverage and feed additives. Compared with the Reichstein method, biotechnological production of vitamin C is an attractive approach due to the low cost and high product quality. In this chapter, biosynthesis of vitamin C, including one-step fermentation processes and two-step fermentation processes are discussed and compared. Furthermore, the prospects of the biotechnological production of vitamin C are also presented.