Biosynthesis of allantoin in Escherichia coli via screening a highly effective urate oxidase

Abstract

Allantoin is an important fine chemical that can be widely used in pharmaceutical, cosmetic and agricultural industries. Currently, allantoin is mainly produced by plant extraction or chemical synthesis. Due to the cost and environmental concerns, biosynthesis of allantoin from renewable feedstock is much more desirable.However, microbial production of allantoin from simple carbon sources has not yet been achieved so far. In this study, de novo biosynthesis of allantoin was achieved by constructing an artificial biosynthetic pathway. First, screening of efficient urate oxidases and xanthine dehydrogenases enabled allantoin production from hypoxanthine, a natural intermediate in purine metabolic pathway in Escherichia coli. Then, assemble of the entire pathway resulted in 13.9 mg/L allantoin from glucose in shake flask experiments. The titer was further improved to 639.8 mg/L by enhancing the supply of the precursor, redistribution of carbon flux, and reduction of acetate. Finally, scale-up production of allantoin was conducted in a 1-L fermentor under fed-batch culture conditions, which enabled the synthesis of 2360 mg/L allantoin, representing a 170-fold increase compared with the initial strain. This study not only demonstrates the potential for industrial production of allantoin, but also provides a bacterial platform for synthesis of other purinesderived high-value chemicals.

Allantoin and Tissue Specific Redox Regulation in Mud Crab Scylla serrata under Varied Natural Water Physico-Chemical Parameters

“…So, allantoin must have ROS scavenging activity in the crabs. The role of allantoin in modulating stress primarily via NRF2 pathways is known to control several integral processes of aging, neural function, stress relieving, etc., observed in animal models [7,14,29]. Furthermore, this phenomenon has been observed in plant models [62].…”

“…As an inhabitant of the intertidal zone, S. serrata (mud crab) is highly influenced by environmental factors, including pH, salinity, and temperature [26]. In this regard, the antioxidant regulatory capacity of allantoin has been noted in microbes and some invertebrates [27][28][29]. Although the combined effects of various aquatic environmental factors in modulating complex cellular processes and oxidative stress responses in S serrata have been studied, the role of allantoin in this crab under such a context is still obscure.…”

Synthesis of NMN by cascade catalysis of intracellular multiple enzymes

“…Design of NMN synthesis pathway catalyzed by the cascade of intracellular multiple enzymes Currently, the reported routes for NMN biosynthesis mainly use NAM and PRPP as substrates to generate NMN under the catalysis of NAMPT. 14 Owing to the instability of PRPP, 15 it is possible to attempt to synthesize PRPP from other substrates and further generate an NMN. Therefore, based on the pentose phosphate metabolic pathway for the synthesis of PRPP, three in vivo pathways for PRPP synthesis were designed using glucose, xylose, and arabinose as raw materials.…”