Optimization of the purine operon and energy generation in Bacillus amyloliquefaciens for guanosine production

Abstract

The combined modification strategy used in this study is a novel approach to improve the production of guanosine in industrial bacterial strains.

Development of an Inosine Hyperproducer from Bacillus licheniformis by Systems Metabolic Engineering

“…The gene purF encodes amidophosphoribosyltransferase, which is a rate-limiting enzyme in the production of purine nucleosides. 19 The transcription level of purF in strain IR-1−1 increased by 1323% compared to that of DW2 (Figure S1). Additionally, the transcription levels of yf kN and guaC, which encode 5′-nucleotidase and GMP reductase, respectively, were increased by 386% and 375% (Figure S1), and the concentrations of intracellular hypoxanthine, guanine, and adenine were increased by 9.27-, 2.39-, and 5.32-fold, respectively (Figure 2B).…”

Metabolic engineering of Bacillus subtilis for high‐titer production of menaquinone‐7

“…Dissolved oxygen plays an important role in the cell growth, especially in the industry‐scale fermentation processes. In B. subtilis , the aerobic respiratory system contains four terminal oxidases: cytochrome caa 3 , which is a cytochrome c oxidase, cytochrome aa 3, and bd , and a putative YthAB oxidase, which are quinol oxidases (Figure ) . Under aerobic conditions, cytochrome bd encoded by cyd plays a minor role during rapid growth, and the deletion of cyd increases the efficiency of energy generation .…”

“…Under aerobic conditions, cytochrome bd encoded by cyd plays a minor role during rapid growth, and the deletion of cyd increases the efficiency of energy generation . A previous study showed that the deletion of cyd resulted in a high guanosine yield in B. amyloliquefaciens XH7 . So we knocked out the cyd gene to investigate its effect on MK‐7 synthesis.…”

Metabolic Engineering of Bacillus licheniformis for the Bioproduction of Nicotinamide Riboside from Nicotinamide and Glucose

“…Bacillus has been recognized as the superior producing strains for the production of purine nucleoside. For example, Liao et al acquired 19 g/L of guanosine in Bacillus amyloliquefaciens after optimizing purine operon and energy generation . The production of inosine in Bacillus subtilis was increased to 7.6 g/L when the synthesis of adenosine monophosphate and the degradation of inosine were blocked by deletion of the adenylosuccinate synthase gene ( purA ) and the purine nucleoside phosphorylase (PNP) gene ( deoD ) .…”

“…For example, Liao et al acquired 19 g/L of guanosine in Bacillus amyloliquefaciens after optimizing purine operon and energy generation. 21 The production of inosine in Bacillus subtilis was increased to 7.6 g/L when the synthesis of adenosine monophosphate and the degradation of inosine were blocked by deletion of the adenylosuccinate synthase gene (purA) and the purine nucleoside phosphorylase (PNP) gene (deoD). 22 Deletion of the guaA gene encoding the GMP synthase and overexpression of the purA gene in B. subtilis resulted in the production of adenosine at a titer of 14.39 g/L.…”