Expression of the NADPH + -Dependent Formate-Dehydrogenase Gene from Pseudomona s Increases Lysine Production in Coryneb
- PDF / 427,796 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 76 Downloads / 177 Views
UCERS, BIOLOGY, SELECTION, AND GENE ENGINEERING
Expression of the NADPH+-Dependent Formate-Dehydrogenase Gene from Pseudomonas Increases Lysine Production in Corynebacterium glutamicum L. E. Ryabchenkoa, *, T. E. Leonovaa, T. E. Shustikovaa, T. V. Gerasimovaa, T. A. Ivankovaa, K. V. Sidorenkoa, and A. S. Yanenkoa aState Research Institute for Genetics and Selection of Industrial Microorganisms, Kurchatov Institute National Research Center
(Kurchatov Institute NRC, GOSNIIgenetika), Moscow, 117545 Russia *e-mail: [email protected] Received November 12, 2019; revised November 20, 2019; accepted November 27, 2019
Abstract—The psefdh_D221Q gene encodes a mutant formate dehydrogenase from Pseudomonas (PseFDG_D221Q), which catalyzes formate oxidation with the simultaneous formation of NADPH. It is expressed in cells of lysine-producing Corynebacterium glutamicum strains. The psefdh_D221Q gene was introduced into C. glutamicum strains as part of an autonomous plasmid or was integrated into the chromosome with the simultaneous inactivation of the host formate-dehydrogenase genes. It was shown that the C. glutamicum strains with NADP+-dependent formate dehydrogenase have an increased level of L-lysine synthesis in the presence of formate if their own formate dehydrogenase is inactivated. Keywords: L-lysine, formate dehydrogenase, NADPH, Corynebacterium glutamicum DOI: 10.1134/S0003683820080086
INTRODUCTION The level of synthesis of the aspartate family of amino acids (threonine, methionine, lysine, and isoleucine) in bacteria cells largely depends on the availability of the cofactor NADPH (Figure 1). The presence of sufficient amounts of this cofactor in the cell is of special importance for L-lysine biosynthesis. The production of one L-lysine molecule requires four NADPH molecules (Figure 1) [1, 2]. It is known that, in Corynebacterium glutamicum cells, which are the key producer of amino acids [3–5], this cofactor is synthesized in the oxidative branch of the pentosophosphate pathway with the participation of two enzymes, glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) [6]. The cofactor is also produced in the tricarboxylic acid cycle with the involvement of isocitrate dehydrogenase (EC 1.1.1.42) [7] and malic enzyme (EC 1.1.1.40), which converts malate into pyruvate [8] (Figure 1). Analysis of the metabolic flow showed that the NADPH in L-lysine-producing C. glutamicum cells is predominantly synthesized in the pentosomonophosphate pathway oxidative branch [9]. However, the synthesis of two NADPH molecules in this pathway is Abbreviations: CL—culture liquid; FDH–formate dehydrogenase; NADPH—nicotinamide-β-adenine dinucleotide phosphate, reduced; OD—optical density; PdeFDH_D221Q— NADPH+-dependent FDH with the D221Q mutation.
accompanied by the loss of one carbon atom from the glucose molecule in the form of CO2 (Figure 1). In this regard, it seems promising to use other metabolic reactions of NADPH synthesis to increase the level of lysine production. One approach
Data Loading...
