초록
<P><B>Background</B></P><P><SMALL>L</SMALL>-arginine is an important amino acid with applications in diverse industrial and pharmaceutical fields. <SMALL>N</SMALL>-acetylglutamate, synthesized from <SMALL>L</SMALL>-glutamate and acetyl-CoA, is a precursor of the <SMALL>L</SMALL>-arginine biosynthetic branch in microorganisms. The enzyme that produces <SMALL>N</SMALL>-acetylglutamate, <SMALL>N</SMALL>-acetylglutamate synthase, is allosterically inhibited by <SMALL>L</SMALL>-arginine. <SMALL>L</SMALL>-glutamate, as a central metabolite, provides carbon backbone for diverse biological compounds besides <SMALL>L</SMALL>-arginine. When glucose is the sole carbon source, the theoretical maximum carbon yield towards <SMALL>L</SMALL>-arginine is 96.7%, but the experimental highest yield was 51%. The gap of <SMALL>L</SMALL>-arginine yield indicates the regulation complexity of carbon flux and energy during the <SMALL>L</SMALL>-arginine biosynthesis. Besides endogenous biosynthesis, <SMALL>N</SMALL>-acetylglutamate, the key precursor of <SMALL>L</SMALL>-arginine, can be obtained by chemical acylation of <SMALL>L</SMALL>-glutamate with a high yield of 98%. To achieve high-yield production of <SMALL>L</SMALL>-arginine, we demonstrated a novel approach by directly feeding precursor <SMALL>N</SMALL>-acetylglutamate to engineered <I>Escherichia coli</I>.</P><P><B>Results</B></P><P>We reported a new approach for the high yield of <SMALL>L</SMALL>-arginine production in <I>E. coli.</I> Gene <I>argA</I> encoding <SMALL>N</SMALL>-acetylglutamate synthase was deleted to disable endogenous biosynthesis of <SMALL>N</SMALL>-acetylglutamate. The feasibility of external <SMALL>N</SMALL>-acetylglutamate towards <SMALL>L</SMALL>-arginine was verified via growth assay in <I>argA</I><SUP>−</SUP> strain. To improve <SMALL>L</SMALL>-arginine production, <I>astA</I> encoding arginine <SMALL>N</SMALL>-succinyltransferase, <I>speF</I> encoding ornithine decarboxylase, <I>speB</I> encoding agmatinase, and <I>argR</I> encoding an arginine responsive repressor protein were disrupted. Based on overexpression of <I>argDGI, argCBH</I> operons<I>,</I> encoding enzymes of the <SMALL>L</SMALL>-arginine biosynthetic pathway, ~ 4 g/L <SMALL>L</SMALL>-arginine was produced in shake flask fermentation, resulting in a yield of 0.99 mol <SMALL>L</SMALL>-arginine/mol <SMALL>N</SMALL>-acetylglutamate. This strain was further engineered for the co-production of <SMALL>L</SMALL>-arginine and pyruvate by removing genes <I>adhE, ldhA, poxB, pflB,</I> and <I>aceE,</I> encoding enzymes involved in the conversion and degradation of pyruvate<I>.</I> The resulting strain was shown to produce 4 g/L <SMALL>L</SMALL>-arginine and 11.3 g/L pyruvate in shake flask fermentation.</P><P><B>Conclusions</B></P><P>Here, we developed a novel approach to avoid the strict regulation of <SMALL>L</SMALL>-arginine on ArgA and overcome the metabolism complexity in the <SMALL>L</SMALL>-arginine biosynthesis pathway. We achieve a high yield of <SMALL>L</SMALL>-arginine production from <SMALL>N</SMALL>-acetylglutamate in <I>E. coli</I>. Co-production pyruvate and <SMALL>L</SMALL>-arginine was used as an example to increase the utilization of input carbon sources.</P><P><B>Supplementary Information</B></P><P>The online version contains supplementary material available at 10.1186/s12934-023-02145-8.</P>