ABSTRACT
We present a Penicillium rubens strain with an industrial background in which the four highly expressed biosynthetic gene clusters (BGC) required to produce penicillin, roquefortine, chrysogine and fungisporin were removed. This resulted in a minimal secondary metabolite background. Amino acid pools under steady-state growth conditions showed reduced levels of methionine and increased intracellular aromatic amino acids. Expression profiling of remaining BGC core genes and untargeted mass spectrometry did not identify products from uncharacterized BGCs. This platform strain was repurposed for expression of the recently identified polyketide calbistrin gene cluster and achieved high yields of decumbenone A, B and C. The penicillin BGC could be restored through in vivo assembly with eight DNA segments with short overlaps. Our study paves the way for fast combinatorial assembly and expression of biosynthetic pathways in a fungal strain with low endogenous secondary metabolite burden.
Subject(s)
Metabolic Engineering , Penicillium/metabolism , Secondary Metabolism , Biosynthetic Pathways/genetics , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Fungal , Genome, Fungal , Genomics/methods , Multigene Family , Penicillium/classification , Penicillium/genetics , Peptide Synthases/genetics , Peptide Synthases/metabolism , TranscriptomeABSTRACT
Chrysogine is a yellow pigment produced by Penicillium chrysogenum and other filamentous fungi. Although the pigment was first isolated in 1973, its biosynthetic pathway has so far not been resolved. Here, we show that deletion of the highly expressed nonribosomal peptide synthetase (NRPS) gene Pc21g12630 (chyA) resulted in a decrease in the production of chrysogine and 13 related compounds in the culture broth of P. chrysogenum Each of the genes of the chyA-containing gene cluster was individually deleted, and corresponding mutants were examined by metabolic profiling in order to elucidate their function. The data suggest that the NRPS ChyA mediates the condensation of anthranilic acid and alanine into the intermediate 2-(2-aminopropanamido)benzoic acid, which was verified by feeding experiments of a ΔchyA strain with the chemically synthesized product. The remainder of the pathway is highly branched, yielding at least 13 chrysogine-related compounds.IMPORTANCEPenicillium chrysogenum is used in industry for the production of ß-lactams, but also produces several other secondary metabolites. The yellow pigment chrysogine is one of the most abundant metabolites in the culture broth, next to ß-lactams. Here, we have characterized the biosynthetic gene cluster involved in chrysogine production and elucidated a complex and highly branched biosynthetic pathway, assigning each of the chrysogine cluster genes to biosynthetic steps and metabolic intermediates. The work further unlocks the metabolic potential of filamentous fungi and the complexity of secondary metabolite pathways.
Subject(s)
Biosynthetic Pathways/genetics , Penicillium chrysogenum/genetics , Quinazolinones/metabolism , Multigene Family , Penicillium chrysogenum/metabolism , Peptide Synthases/metabolism , Pigmentation , Secondary MetabolismABSTRACT
This article provides the dataset of operating conditions of a hybrid organic Rankine plant generated by the optimization procedure employed in the research article "A genetic optimization of a hybrid organic Rankine plant for solar and low-grade energy sources" (Scardigno et al., 2015) [1]. The methodology used to obtain the data is described. The operating conditions are subdivided into two separate groups: feasible and unfeasible solutions. In both groups, the values of the design variables are given. Besides, the subset of feasible solutions is described in details, by providing the thermodynamic and economic performances, the temperatures at some characteristic sections of the thermodynamic cycle, the net power, the absorbed powers and the area of the heat exchange surfaces.
