Search

Prodigiosin (PG) is a potential red pigment mainly produced from microbes (mainly from Serratia marcescens) that has attracted much research interest due to its possessing multi-bioactivities applied in various fields. However, its hydrophobic nature makes this compound poorly absorbed, and low bioavailability hinders its pure-form applications. Its nanoforms can improve these disadvantages, such as good solubility in water due to being encapsulated inside hydrophilic materials or small size and good interaction on membranes to get higher bioactivity. Thus, prodigiosin-nanocomposites production and application attracted excitement in research. To date, most previous review papers have presented general information on the production and application of pure PG and its nanoform medical effects. A comprehensive review of PG-nanocomposites production and their promising applications is still lacking. In this work, research on pure prodigiosin production will continue to be updated (focus on recent reports from 2022 to the present). The synthesis of PG-nanocomposites by various methods, its diverse nanoform applications, and the toxicity aspect are discussed in detail. Additionally, virtual simulation strategies in prodigiosin research were also presented in the current work. In general, utilizing organic byproducts as a substrate source continues as an interesting eco-friendly fermentation approach currently with low cost, shortened time, and enhanced productivity on a large scale. Besides metal/metal oxide conjugate or physical methods, PG-nanocomposites are produced the most commonly by nanoencapsulation methods. Applied studies of PG-nanocomposites mainly explore their medical effects. Virtual computer simulations are also useful tools for PG research, although more in-depth simulations are needed. [ABSTRACT FROM AUTHOR]

The opportunistic pathogen Serratia sp. ATCC 39006 (S39006) is a rod-shaped, motile, Gram-negative bacterium that produces a -lactam antibiotic (a carbapenem) and a bioactive red-pigmented tripyrrole antibiotic, prodigiosin. It is also the only known enterobacterium that naturally produces intracellular gas vesicles (GVs), enabling cells to float in static water columns. Regulation of GVs and secondary metabolites in S39006 can be coordinated but such pleiotropy is still poorly understood. To uncover novel inputs to this complex regulatory network, we used transposon mutagenesis to identify a mutant with an insertion in an IclR-type transcriptional regulator gene. The iclR mutant showed diminished production of carbapenem, prodigiosin, GVs and cellulase. Furthermore, the mutant also showed increased swimming and swarming motilities but exhibited attenuated virulence in planta and ability to kill the nematode C. elegans. Using differential expression analysis of the intracellular proteomes of the wild type and iclR mutant, we confirmed that the mutation negatively impacted expression of the corresponding GV, carbapenem and prodigiosin gene clusters. In contrast, flagellar and chemotaxis proteins were overexpressed, consistent with the increased motility of the mutant. We also found that the proteins encoded by a putative yagEF-yjhF operon, involved in xylonate catabolism and transport, showed a 5- to 7-fold increase in expression. Finally, we show that IclR is a repressor of xylonate catabolism in S39006 and suggest that xylonate is potentially involved in controlling carbapenem and prodigiosin biosynthesis. Our results indicate that IclR is a global regulator that controls antibiotic biosynthesis, flotation through modulating GV assembly, and has pleiotropic impacts on the physiology and virulence of S39006. Based on these findings, we propose the designation of this IclR-family transcriptional regulator as XyrR (Xy lonate r esponse R egulator). [ABSTRACT FROM AUTHOR]

Prodigiosin, a valuable intracellular secondary metabolite, is produced by Serratia marcescens. However, synthesis during fermentation is constrained by osmotic pressure. In this study, adaptive laboratory evolution was applied to the strain SDSPY-136 to improve osmotic stress tolerance. After 120 passages, screening and validation yielded a strain with high osmotic pressure resistance, S. marcescens R82. The UV absorption spectrum, HPLC peak time, FTIR functional groups, and 1H NMR chemical shifts revealed that the pigment generated by the evolved strain was prodigiosin. After batch fermentation in a 5 L bioreactor, the prodigiosin concentration was 11.4 g/L, double the initial strain. Transcriptomic analyses revealed significant enrichment for 830 genes. R82 showed alterations in various pathways, indicating that the regulation of intracellular metabolic pathways promoted the availability of prodigiosin precursors, increasing the capacity for prodigiosin synthesis and extracellular release. This study clarifies the molecular evolution mechanism and presents a novel approach for improving yields in S. marcescens. [Display omitted] • Serratia marcescens was modified through adaptive laboratory evolution. • Pigment of the evolved R82 strain was characterized using spectroscopy. • Strain R82 was tolerant to osmotic pressure. • Batch fermentation yielded 11.4 g/L prodigiosin in 5 L bioreactors. • Transcriptome sequencing was used to analyze the evolutionary mechanism. [ABSTRACT FROM AUTHOR]

Simple Summary: The ambrosia beetle Euwallacea interjectus, a pest of economic tree species, has caused significant damage to Chinese poplar plantations since 2020, aided by its symbiosis with Fusarium populicola. Current control relies on tree removal and chemicals, with limited biological control options. This study evaluated several potential biocontrol agents, including Beauveria bassiana, Serratia marcescens, and its metabolite prodigiosin, and the ectoparasitic mites Pyemotes moseri and P. zhonghuajia. While these agents showed promise in laboratory tests, further investigation is needed for field application. The ambrosia beetle Euwallacea interjectus Blandford (Coleoptera: Curculionidae: Scolytinae) has recently emerged as a pest in Chinese poplar plantations, causing significant economic losses through damage to host trees in association with its mutualistic fungus Fusarium populicola. This study evaluated the biocontrol potential of Beauveria bassiana strain B-BB-1, Serratia marcescens strain B-SM-1, its metabolite prodigiosin, and two ectoparasitic mites, Pyemotes moseri and Pyemotes zhonghuajia. B. bassiana exhibited significant lethality toward adult female E. interjectus, reduced offspring production, and inhibited F. populicola growth. S. marcescens and prodigiosin had certain lethal effects on larvae and inhibited the growth of F. populicola. Both mites effectively parasitized beetle pupae and larvae, with no significant differences in efficacy between the two species. These agents demonstrate promise for the biological control of E. interjectus, offering insights for managing ambrosia beetle infestations. [ABSTRACT FROM AUTHOR]

The opportunistic pathogen Serratia sp. ATCC 39006 (S39006) is a rod-shaped, motile, Gram-negative bacterium that produces a 𝛽-lactam antibiotic (a carbapenem) and a bioactive red-pigmented tripyrrole antibiotic, prodigiosin. It is also the only known enterobacterium that naturally produces intracellular gas vesicles (GVs), enabling cells to float in static water columns. Regulation of GVs and secondary metabolites in S39006 can be coordinated but such pleiotropy is still poorly understood. To uncover novel inputs to this complex regulatory network, we used transposon mutagenesis to identify a mutant with an insertion in an IclR-type transcriptional regulator gene. The iclR mutant showed diminished production of carbapenem, prodigiosin, GVs and cellulase. Furthermore, the mutant also showed increased swimming and swarming motilities but exhibited attenuated virulence in planta and ability to kill the nematode C. elegans. Using differential expression analysis of the intracellular proteomes of the wild type and iclR mutant, we confirmed that the mutation negatively impacted expression of the corresponding GV, carbapenem and prodigiosin gene clusters. In contrast, flagellar and chemotaxis proteins were overexpressed, consistent with the increased motility of the mutant. We also found that the proteins encoded by a putative yagEF-yjhF operon, involved in xylonate catabolism and transport, showed a 5- to 7-fold increase in expression. Finally, we show that IclR is a repressor of xylonate catabolism in S39006 and suggest that xylonate is potentially involved in controlling carbapenem and prodigiosin biosynthesis. Our results indicate that IclR is a global regulator that controls antibiotic biosynthesis, flotation through modulating GV assembly, and has pleiotropic impacts on the physiology and virulence of S39006. Based on these findings, we propose the designation of this IclR-family transcriptional regulator as XyrR (Xylonate response Regulator).

Prodigiosin (PG) is a natural compound produced by microorganisms, that is known for its promising bioactive properties. However, owing to its inherent water insolubility, low bioavailability, and poor stability, the practical application of prodigiosin remains challenging. In this work, the nanoparticles of prodigiosin-loaded zein-pectin were prepared using electrostatic deposition and antisolvent precipitation methods. The encapsulation efficiency and loading capacity of prodigiosin in Z -Pet/PG 2:1 nanoparticles were 89.05 % and 7.49 %, respectively, with a zeta potential of −23.03 mV, with a particle size was 184.13 nm. The nanoparticles were uniformly distributed and possessed a spherical morphology, as determined using scanning electron microscopy. The formation mechanism between nanoparticles has been investigated using circular dichroism, fluorescence spectroscopy, molecular docking, and Fourier-transform infrared spectroscopy, which indicated stabilization predominantly through electrostatic, hydrophobic, and hydrogen-bonding interactions. Furthermore, Z -Pet/PG 2:1 nanoparticles proved remarkable stability across a pH range from 3 to 7, NaCl concentrations below 50 mmol/L, at elevated temperatures (60, 70, and 80 °C) for 1 h, and at redispersion. Prodigiosin was progressively delivered by the nanoparticles in simulated gastrointestinal settings, with a cumulative release rate of 75.32 % in simulated intestinal fluid, thereby demonstrating enhanced bioavailability and allowing for a controlled and sustained-release in vitro. These findings indicate that Z -Pet/PG nanoparticles are a promising delivery platform for prodigiosin, and are potentially applicable to other hydrophobic compounds with limited bioavailability. • Prodigiosin loaded zein/pectin nanoparticles(Z-Pet/PG) were prepared. • Zein-to-pectin mass ratios influenced the physicochemical properties of the nanoparticles. • The formation mechanism of Z-Pet/PG nanoparticles was investigated. • The nanoparticles exhibit excellent environmental stability. • Z-Pet/PG could be released under regulated conditions in simulated intestinal fluids. [ABSTRACT FROM AUTHOR]