Intensification of 2′-Fucosyllactose biosynthesis pathway by using a novel fucosyltransferase from Bacillus cereus
Kainuo Zhang, Miaomiao Gao, Chenqi Cao, Mengxin Zhang, Waqar Ahmad, Ahmed Rady, Badr Aldahmash, Tianze Zhu, Shahin Shah Khan, Luo Liu
Abstract
Introduction 2′-Fucosyllactose (2′-FL) is an oligosaccharide that can be synthesized in the human body and is known for its health-promoting and prebiotic effects. The biosynthesis of 2′-FL using microorganisms has received attention recently due to its increased application in nutritional and medical infant formulations. Methods This work attempts the new application of Bacillus cereus α-1,2-fucosyltransferase (FutCB) in the de novo synthesis of 2′-FL in Escherichia coli ( E. coli ). Additionally, knocking out the LacZ and WaaF genes alongside overexpression of the key gmd, manB, wcaG, and manC genes enhances the availability of the necessary precursors GDP-L-fucose and lactose for the synthesis of 2′-FL. Results and discussion The use of constitutive promoters achieved better control over the production of 2′-FL during fed-batch fermentation. After 64 h of fermentation, the modified E. coli strains produced 121.4 g/L 2′-FL with a yield of 1.90 g/L/h, resulting in an impressive 2′-FL output. These results together indicate the potential of large-scale, high-yield production of 2′-FL and form a basis of much more refinement to be done. The next step will focus on maximum substrate utilization, alteration of gene regulation, and improvement of commercial-scale synthesis.