Natural Pigments of Microbial Origin Pailliè-Jiménez, Maria Elisa; Stincone, Paolo; Brandelli, Adriano
Frontiers in sustainable food systems,
09/2020, Letnik:
4
Journal Article
Recenzirano
Odprti dostop
The world demands new solutions and products to be used as dyes for industrial applications. Microbial pigments represent an eco-friendly alternative as they can be produced in large amounts through ...biotechnological processes and do not present environmental risks, as they are easily decomposable. Moreover, some of these metabolites are recognized for their biological activities, which qualify them for potential uses as food colorants and nutraceuticals, protecting against degenerative diseases related with oxidative stress. Because of their genetic simplicity as compared with plants, microorganisms may be a better source to understand biosynthetic mechanisms and to be engineered for producing high pigment yields. Despite the origin of the pigmented microorganism, it seems very important to develop protocols using organic industrial residues and agricultural byproducts as substrates for pigment production and find novel green strategies for rapid pigment extraction. This review looks for the most recent studies that describe microbial pigments from microalgae, fungi, and bacteria. In particular, the underexploited tools of omics science such as proteomics and metabolomics are addressed. The use of techniques involving mass spectrometry, allows to identify different protein and metabolite profiles that may be associated with a variety of biotechnologically-relevant pathways of pigment synthesis.
The marine environment encompasses a huge biological diversity and can be considered as an underexplored location for prospecting bioactive molecules. In this review, the current state of art about ...antimicrobial molecules from marine bacteria has been summarized considering the main phylum and sources evolved in a marine environment. Considering the last two decades, we have found as most studied group of bacteria producers of substances with antimicrobial activity is the Firmicutes phylum, in particular strains of the Bacillus genus. The reason for that can be attributed to the difficult cultivation of typical Actinobacteria from a marine sediment, whose members are the major producers of antimicrobial substances in land environments. However, a reversed trend has been observed in recent years with an increasing number of reports settling on Actinobacteria. Great diversity of chemical structures have been identified, such as fijimicyns and lynamicyns from Actinomycetes and macrolactins produced by Bacillus.
Pseudomonas sp. 4B isolated from the effluent pond of a bovine abattoir was investigated as antifungal against toxigenic fungi. The complete genome of Pseudomonas 4B was sequenced using the Illumina ...MiSeq platform. Phylogenetic analysis and genome comparisons indicated that the strain belongs to the Pseudomonas aeruginosa group. In silico investigation revealed gene clusters associated with the biosynthesis of several antifungals, including pyocyanin, rhizomide, thanamycin, and pyochelin. This bacterium was investigated through antifungal assays, showing an inhibitory effect against all toxigenic fungi tested. Bacterial cells reduced the diameter of fungal colonies, colony growth rate, and sporulation of each indicator fungi in 10-day simultaneous growing tests. The co-incubation of bacterial suspension and fungal spores in yeast extract-sucrose broth for 48 h resulted in reduced spore germination. During simultaneous growth, decreased production of aflatoxin B1 and ochratoxin A by Aspergillus flavus and Aspergillus carbonarius, respectively, was observed. Genome analysis and in vitro studies showed the ability of P. aeruginosa 4B to reduce fungal growth parameters and mycotoxin levels, indicating the potential of this bacterium to control toxigenic fungi. The broad antifungal activity of this strain may represent a sustainable alternative for the exploration and subsequent use of its possible metabolites in order to control mycotoxin-producing fungi.
The cellular proteins of L. monocytogenes exposed to free and liposome-encapsulated nisin at sublethal concentration were hydrolyzed by trypsin and examined by tandem mass spectrometry (MS/MS) to ...obtain proteomic data. In the present study, we use the STRING v11.05 database analyze the interactions among the 78 upregulated proteins from L. monocytogenes obtained after treatment with sublethal concentrations of free and nanoliposome-encapsulated nisin. As result, from the upregulated proteins by free nisin was determined a network with 140 edges with two relevant nodes, containing ribosomal proteins and transmembrane transport proteins (SecD and ABC transport system). These two sets of proteins present biological connection as a group, with strong interactions and are related to detoxification and other Listeria response mechanisms. In addition, a high amount of membrane proteins was identified in the free nisin treatment. On the other hand, in the interaction analysis of upregulated proteins by liposome-loaded nisin, was found 156 edges with a single protein network, the same observed in free nisin, related to ribosomal proteins. Therefore, according with this analysis, the encapsulation of nisin into liposomes cause upregulation of ribosomal and decrease of L. monocytogenes response proteins as compared with free nisin.
The antimicrobial activities of
Baccharis dracunculifolia
DC essential oil (EO) and hydroalcoholic extract (HE) were evaluated. The EO showed broad antimicrobial activity and its synergistic ...combination with nisin was tested. Major components of EO were nerolidol, beta-pinene and D-limonene, while artepillin C, rutin and cafeic acid were major phenolics of HE. EO and HE were tested by agar diffusion assay against several strains of bacteria and yeasts, and mixed cultures of bacterial strains. The EO presented the largest spectrum of antimicrobial activity inhibiting all Gram-positive bacteria tested. Yeasts were not inhibited. The effect of EO against mixtures of sensitive and non-sensitive bacteria was tested on milk agar, being the inhibitory effect only observed on mixtures containing susceptible strains. The combination of EO and nisin at ½ MIC was evaluated on the growth curve of
Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes
and
Salmonella
Enteritidis during 24 h at 37 °C. The combination EO-nisin was effective and no viable counts of
B. cereus, L. monocytogenes
and
S
. Enteritidis was observed, while the individual antimicrobials caused no inhibition. The counts of
S. aureus
were about 4 log CFU/mL lower in comparison with EO or nisin alone.
B. dracunculifolia
DC may be a potential source of natural antimicrobials, and its synergistic effect with nisin would reduce the working concentration, minimizing the organoleptic effects associated with this plant antimicrobial.
The ability of Listeria monocytogenes grow on ready-to-eat food is a major concern in food safety. Natural antimicrobials, such as nisin, can be used to control this pathogen, but the increasing ...reports of nisin tolerance and resistance make necessary novel approaches to increase its effectiveness, such as encapsulation. The goal of this study was to investigate how L. monocytogenes ATCC7644 regulates and shapes its proteome in response to sublethal doses of nisin and nisin-loaded phosphatidylcholine liposomes (lipo-nisin), compared to untreated cells growing under optimal conditions. Total proteins were extracted from L. monocytogenes cells treated for 1 h with free and lipo-nisin. As result, of 803 proteins that were initially identified, 64 and 53 proteins were differentially upregulated and downregulated respectively, in the treatments with nisin and lipo-nisin. Changes of Listeria proteome in response to treatments containing nisin were mainly related to ATP-binding cassette (ABC) transporter systems, transmembrane proteins, RNA-binding proteins and diverse stress response proteins. Some of the proteins uniquely detected in samples treated with free nisin were the membrane proteins SecD, Lmo1539 and the YfhO enzyme, which are related to translocation of L. monocytogenes virulence factors, activation of the LiaR-mediated stress defense and glycosylation of wall teichoic acid, respectively. The L. monocytogenes treated with liposome encapsulated nisin showed no expression of some stress response factors as compared with the free nisin, suggesting a reduction of stress mediated response and production of nisin-resistance factors by exposure to encapsulated nisin.
•Free and encapsulated nisin influence the proteome profile of L. monocytogenes.•Differential proteome profile observed in comparison with untreated cells.•Some proteins related to virulence and stress response only induced by free nisin.•Liposome encapsulation could be a strategy to reduce nisin resistance.
With the emergence of next‐generation nucleotide sequencing and mass spectrometry‐based proteomics and metabolomics tools, we have comprehensive and scalable methods to analyze the genes, ...transcripts, proteins, and metabolites of a multitude of biological systems. Despite the fascinating new molecular insights at the genome, transcriptome, proteome and metabolome scale, we are still far from fully understanding cellular organization, cell cycles and biology at the molecular level. Significant advances in sensitivity and depth for both sequencing as well as mass spectrometry‐based methods allow the analysis at the single cell and single molecule level. At the same time, new tools are emerging that enable the investigation of molecular interactions throughout the central dogma of molecular biology. In this review, we provide an overview of established and recently developed mass spectrometry‐based tools to probe metabolite‐protein interactions—from individual interaction pairs to interactions at the proteome‐metabolome scale.
Quinones are among the most important components in natural organic matter (NOM) for redox reactions; however, no quinones in complex environmental media have been identified. To aid the ...identification of quinone-containing molecules in ultracomplex environmental samples, we developed a chemical tagging method that makes use of a Michael addition reaction between quinones and thiols (-SH) in cysteine (Cys) and cysteine-contained peptides (CCP). After the tagging, candidates of quinones in representative aqueous environmental samples (water extractions of biochar) were identified through high-resolution mass spectrometry (HRMS) analysis. The MS and UV spectra analysis showed rapid reactions between Cys/CCP and model quinones with β-carbon from the same benzene ring available for Michael addition. The tagging efficiency was not influenced by other co-occurring nonquinone representative compounds, including caffeic acid, cinnamic acid, and coumaric acid. Cys and CCP were used to tag quinones in water extractions of biochars, and possible candidates of quinones (20 and 53 based on tagging with Cys and CCP, respectively) were identified based on the HRMS features for products of reactions with Cys/CCP. This study has successfully demonstrated that such a Michael addition reaction can be used to tag quinones in complex environmental media and potentially determine their identities. The method will enable an in-depth understanding of the redox chemistry of NOM and its critical chemical compositions and structures.Quinones are among the most important components in natural organic matter (NOM) for redox reactions; however, no quinones in complex environmental media have been identified. To aid the identification of quinone-containing molecules in ultracomplex environmental samples, we developed a chemical tagging method that makes use of a Michael addition reaction between quinones and thiols (-SH) in cysteine (Cys) and cysteine-contained peptides (CCP). After the tagging, candidates of quinones in representative aqueous environmental samples (water extractions of biochar) were identified through high-resolution mass spectrometry (HRMS) analysis. The MS and UV spectra analysis showed rapid reactions between Cys/CCP and model quinones with β-carbon from the same benzene ring available for Michael addition. The tagging efficiency was not influenced by other co-occurring nonquinone representative compounds, including caffeic acid, cinnamic acid, and coumaric acid. Cys and CCP were used to tag quinones in water extractions of biochars, and possible candidates of quinones (20 and 53 based on tagging with Cys and CCP, respectively) were identified based on the HRMS features for products of reactions with Cys/CCP. This study has successfully demonstrated that such a Michael addition reaction can be used to tag quinones in complex environmental media and potentially determine their identities. The method will enable an in-depth understanding of the redox chemistry of NOM and its critical chemical compositions and structures.
Understanding the chemical nature of soil organic carbon (SOC) with great potential to bind iron (Fe) minerals is critical for predicting the stability of SOC. Organic ligands of Fe are among the top ...candidates for SOCs able to strongly sorb on Fe minerals, but most of them are still molecularly uncharacterized. To shed insights into the chemical nature of organic ligands in soil and their fate, this study developed a protocol for identifying organic ligands using ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) and metabolomic tools. The protocol was used for investigating the Fe complexes formed by model compounds of lignin-derived organic ligands, namely, caffeic acid (CA), p-coumaric acid (CMA), vanillin (VNL), and cinnamic acid (CNA). Isotopologue analysis of 54/56Fe was used to screen out the potential UHPLC-HRMS (m/z) features for complexes formed between organic ligands and Fe, with multiple features captured for CA, CMA, VNL, and CNA when 35/37Cl isotopologue analysis was used as supplementary evidence for the complexes with Cl. MS/MS spectra, fragment analysis, and structure prediction with SIRIUS were used to annotate the structures of mono/bidentate mono/biligand complexes. The analysis determined the structures of monodentate and bidentate complexes of FeLxCly (L: organic ligand, x = 1–4, y = 0–3) formed by model compounds. The protocol developed in this study can be used to identify unknown organic ligands occurring in complex environmental samples and shed light on the molecular-level processes governing the stability of the SOC.
With the onset of
Listeria monocytogenes
resistance to the bacteriocin nisin, the search for alternative antimicrobial treatments is of fundamental importance. In this work, we set out to investigate ...proteins and lipids involved in the resistance mechanisms of
L. monocytogenes
against the antimicrobial peptides (AMPs) nisin and fengycin. The effect of sub-lethal concentrations of nisin and lipopeptide fengycin secreted by
Bacillus velezensis
P34 on
L. monocytogenes
was investigated by mass spectrometry-based lipidomics and proteomics. Both AMPs caused a differential regulation of biofilm formation, confirming the promotion of cell attachment and biofilm assembling after treatment with nisin, whereas growth inhibition was observed after fengycin treatment. Anteiso branched-chain fatty acids were detected in higher amounts in fengycin-treated samples (46.6%) as compared to nisin-treated and control samples (39.4% and 43.4%, respectively). In addition, a higher relative abundance of 30:0, 31:0 and 32:0 phosphatidylglycerol species was detected in fengycin-treated samples. The lipidomics data suggest the inhibition of biofilm formation by the fengycin treatment, while the proteomics data revealed downregulation of important cell wall proteins involved in the building of biofilms, such as the lipoteichoic acid backbone synthesis (Lmo0927) and the flagella-related (Lmo0718) proteins among others. Together, these results provide new insights into the modification of lipid and protein profiles and biofilm formation in
L. monocytogenes
upon exposure to antimicrobial peptides.
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