Enhancing armeniaspirols production through multi-level engineering of a
native Streptomyces producer
Abstract
Nature has provided unique molecular scaffolds for applications
including therapeutics, agriculture, and food. Due to differences in
ecological environments and laboratory conditions, engineering is often
necessary to uncover and utilize the chemical diversity. Although we can
efficiently activate and mine these often complex 3D molecules,
sufficient production of target molecules for further engineering and
application remain a considerable bottleneck. An example of these
bioactive scaffolds are armeniaspirols, which are potent polyketide
antibiotics against gram-positive pathogens and multi-resistance
gram-negative Helicobacter pylori. Here, we examine upregulation
of armeniaspirols through engineering of biosynthetic pathways and
primary metabolism; including perturbation of genes in biosynthetic gene
clusters and regulation for triacylglycerols pool towards armeniaspirol
upregulation. With either overexpression of extender unit pathway or
late-stage N-methylation, or the deletion of a competing
polyketide cluster, we can achieve 7-49-fold upregulation of
armeniaspirols production. The most significant upregulation was
achieved by expression of heterologous fatty acyl-CoA synthase, where we
observed not only a 97-fold increase in production yields compared to
wild type, but also an increase in the diversity of observed
armeniaspirol analogs.