Microbial Pyrrolnitrin: Natural Metabolite with Immense Practical Utility

Abstract

Pyrrolnitrin (PRN) is a microbial pyrrole halometabolite of immense antimicrobial significance for agricultural, pharmaceutical and industrial implications. The compound and its derivatives have been isolated from rhizospheric fluorescent or non-fluorescent pseudomonads, Serratia and Burkholderia. They are known to confer biological control against a wide range of phytopathogenic fungi, and thus offer strong plant protection prospects against soil and seed-borne phytopathogenic diseases. Although chemical synthesis of PRN has been obtained using different steps, microbial production is still the most useful option for producing this metabolite. In many of the plant-associated isolates of Serratia and Burkholderia, production of PRN is dependent on the quorum-sensing regulation that usually involves N-acylhomoserine lactone (AHL) autoinducer signals. When applied on the organisms as antimicrobial agent, the molecule impedes synthesis of key biomolecules (DNA, RNA and protein), uncouples with oxidative phosphorylation, inhibits mitotic division and hampers several biological mechanisms. With its potential broad-spectrum activities, low phototoxicity, non-toxic nature and specificity for impacts on non-target organisms, the metabolite has emerged as a lead molecule of industrial importance, which has led to developing cost-effective methods for the biosynthesis of PRN using microbial fermentation. Quantum of work narrating focused research efforts in the emergence of this potential microbial metabolite is summarized here to present a consolidated, sequential and updated insight into the chemistry, biology and applicability of this natural molecule.

Pseudomonas as Versatile Aromatics Cell Factory

“…[82] Pyrrolnitrin is produced by various species with cooccurring ability of phloroglucinol biosynthesis [83] at various concentrations depending on the applied low cost fermentation substrate. [84] Pseudomonads contain innate NRPS for the formation of siderophores, like pyoverdines and azotobactin. [85] Pyoverdines are made in the cytoplasm in response to iron-limiting conditions.…”

“…[ 82 ] Pyrrolnitrin is produced by various species with cooccurring ability of phloroglucinol biosynthesis [ 83 ] at various concentrations depending on the applied low cost fermentation substrate. [ 84 ]…”

Antibacterial Substance Produced by a Soil Bacteria Isolated From Rhizosphere of Zingiber Officinale

“…Therefore, there are 4 possible molecular formulas having OH groups produced by J4 bacteria, namely C21H29N3O5, C21H26N2O5, C17H22N8O3, or C15H35N3O. These molecular formulas differ from the molecular formulas of pyrrolnitrin, cepacin A, and cepacin B, the previously discovered antimicrobial compounds produced by Burkholderia sp [20,22].…”

“…According to the BLAST analysis of the 16S rRNA gene, J4 isolate has a close sequence with Burkholderia sp with the identical percentage of 99%. One of these species is Burkholderia (Pseudomonas) cepacia that produces phenylpyrrole, a broad-spectrum antimicrobial compound called pyrrolnitrin [3-chloro-4-(2'-nitro-3'chlorophenyl) Pyrrole] with the chemical formula C10H6Cl2N2O2 [20]. These compounds are active against filamentous fungi, yeast, and Grampositive bacteria.…”

Plant Growth-Promoting Rhizobacteria as a Green Alternative for Sustainable Agriculture

“…Fluorescent and non-fluorescent strains of Pseudomonas species were reported to produce broad-spectrum antifungal metabolite pyrrolnitrin with excellent fungicidal activity against plant pathogenic fungi such as Rhizoctonia solani, Fusarium graminearum, and Phytophthora capsici [110][111][112]. Pseudomonas and Bacillus sp.…”