scholarly journals Moorea producens gen. nov., sp. nov. and Moorea bouillonii comb. nov., tropical marine cyanobacteria rich in bioactive secondary metabolites

2012 ◽  
Vol 62 (Pt_5) ◽  
pp. 1171-1178 ◽  
Author(s):  
Niclas Engene ◽  
Erin C. Rottacker ◽  
Jan Kaštovský ◽  
Tara Byrum ◽  
Hyukjae Choi ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Polyketide Synthase ◽  
Botanical Nomenclature ◽  
Distinctive Character ◽  
Content Type ◽  
Algae Blooms ◽  
Rich Diversity ◽  
Peptide Synthetase ◽  
Bioactive Secondary Metabolites ◽  
Micro Organisms

The filamentous cyanobacterial genus Moorea gen. nov., described here under the provisions of the International Code of Botanical Nomenclature, is a cosmopolitan pan-tropical group abundant in the marine benthos. Members of the genus Moorea are photosynthetic (containing phycocyanin, phycoerythrin, allophycocyanin and chlorophyll a), but non-diazotrophic (lack heterocysts and nitrogenase reductase genes). The cells (discoid and 25–80 µm wide) are arranged in long filaments (<10 cm in length) and often form extensive mats or blooms in shallow water. The cells are surrounded by thick polysaccharide sheaths covered by a rich diversity of heterotrophic micro-organisms. A distinctive character of this genus is its extraordinarily rich production of bioactive secondary metabolites. This is matched by genomes rich in polyketide synthase and non-ribosomal peptide synthetase biosynthetic genes which are dedicated to secondary metabolism. The encoded natural products are sometimes responsible for harmful algae blooms and, due to morphological resemblance to the genus Lyngbya , this group has often been incorrectly cited in the literature. We here describe two species of the genus Moorea: Moorea producens sp. nov. (type species of the genus) with 3LT as the nomenclature type, and Moorea bouillonii comb. nov. with PNG5-198R as the nomenclature type.

scholarly journals Total Biosynthesis and Diverse Applications of the Nonribosomal Peptide-Polyketide Siderophore Yersiniabactin

2015 ◽  
Vol 81 (16) ◽  
pp. 5290-5298 ◽  
Author(s):  
Mahmoud Kamal Ahmadi ◽  
Samar Fawaz ◽  
Charles H. Jones ◽  
Guojian Zhang ◽  
Blaine A. Pfeifer
Keyword(s):  
Polyketide Synthase ◽  
Parallel Applications ◽  
Total Removal ◽  
Heterologous Host ◽  
Nonribosomal Peptide ◽  
Content Type ◽  
Metal Chelating ◽  
Removal Capacity ◽  
Peptide Synthetase ◽  
Host Infection

ABSTRACTYersiniabactin (Ybt) is a mixed nonribosomal peptide-polyketide natural product natively produced by the pathogenYersinia pestis. The compound enables iron scavenging capabilities upon host infection and is biosynthesized by a nonribosomal peptide synthetase featuring a polyketide synthase module. This pathway has been engineered for expression and biosynthesis usingEscherichia colias a heterologous host. In the current work, the biosynthetic process for Ybt formation was improved through the incorporation of a dedicated step to eliminate the need for exogenous salicylate provision. When this improvement was made, the compound was tested in parallel applications that highlight the metal-chelating nature of the compound. In the first application, Ybt was assessed as a rust remover, demonstrating a capacity of ∼40% compared to a commercial removal agent and ∼20% relative to total removal capacity. The second application tested Ybt in removing copper from a variety of nonbiological and biological solution mixtures. Success across a variety of media indicates potential utility in diverse scenarios that include environmental and biomedical settings.

scholarly journals Biosynthesis of Fusarubins Accounts for Pigmentation of Fusarium fujikuroi Perithecia

2012 ◽  
Vol 78 (12) ◽  
pp. 4468-4480 ◽  
Author(s):  
Lena Studt ◽  
Philipp Wiemann ◽  
Karin Kleigrewe ◽  
Hans-Ulrich Humpf ◽  
Bettina Tudzynski
Keyword(s):  
Secondary Metabolites ◽  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Biological Function ◽  
Fusarium Fujikuroi ◽  
Diverse Group ◽  
Fruiting Bodies ◽  
Content Type ◽  
Encoding Gene

ABSTRACTFusarium fujikuroiproduces a variety of secondary metabolites, of which polyketides form the most diverse group. Among these are the highly pigmented naphthoquinones, which have been shown to possess different functional properties for the fungus. A group of naphthoquinones, polyketides related to fusarubin, were identified inFusariumspp. more than 60 years ago, but neither the genes responsible for their formation nor their biological function has been discovered to date. In addition, although it is known that the sexual fruiting bodies in which the progeny of the fungus develops are darkly colored by a polyketide synthase (PKS)-derived pigment, the structure of this pigment has never been elucidated. Here we present data that link the fusarubin-type polyketides to a defined gene cluster, which we designatefsr, and demonstrate that the fusarubins are the pigments responsible for the coloration of the perithecia. We studied their regulation and the function of the single genes within the cluster by a combination of gene replacements and overexpression of the PKS-encoding gene, and we present a model for the biosynthetic pathway of the fusarubins based on these data.

scholarly journals Polyketide Synthase and Nonribosomal Peptide Synthetase Gene Clusters in Type Strains of the Genus Phytohabitans

Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 257
Author(s):  
Hisayuki Komaki ◽  
Tomohiko Tamura
Keyword(s):  
Secondary Metabolites ◽  
Polyketide Synthase ◽  
Gene Clusters ◽  
Nonribosomal Peptide Synthetase ◽  
Nrps Gene ◽  
Nonribosomal Peptide ◽  
Rare Actinomycetes ◽  
Whole Genomes ◽  
Peptide Synthetase ◽  
Established Genus

(1) Background: Phytohabitans is a recently established genus belonging to rare actinomycetes. It has been unclear if its members have the capacity to synthesize diverse secondary metabolites. Polyketide and nonribosomal peptide compounds are major secondary metabolites in actinomycetes and expected as a potential source for novel pharmaceuticals. (2) Methods: Whole genomes of Phytohabitans flavus NBRC 107702T, Phytohabitans rumicis NBRC 108638T, Phytohabitans houttuyneae NBRC 108639T, and Phytohabitans suffuscus NBRC 105367T were sequenced by PacBio. Polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) gene clusters were bioinformatically analyzed in the genome sequences. (3) Results: These four strains harbored 10, 14, 18 and 14 PKS and NRPS gene clusters, respectively. Most of the gene clusters were annotated to synthesis unknown chemistries. (4) Conclusions: Members of the genus Phytohabitans are a possible source for novel and diverse polyketides and nonribosomal peptides.

scholarly journals Biosynthesis of a Complex Yersiniabactin-Like Natural Product via themicLocus in Phytopathogen Ralstonia solanacearum

2011 ◽  
Vol 77 (17) ◽  
pp. 6117-6124 ◽  
Author(s):  
Martin F. Kreutzer ◽  
Hirokazu Kage ◽  
Peter Gebhardt ◽  
Barbara Wackler ◽  
Hans P. Saluz ◽  
...  
Keyword(s):  
Natural Product ◽  
Gene Cluster ◽  
Ralstonia Solanacearum ◽  
Insertional Mutagenesis ◽  
Polyketide Synthase ◽  
Genome Mining ◽  
Content Type ◽  
A Genome ◽  
Iron Deficient ◽  
Peptide Synthetase

ABSTRACTA genome mining study in the plant pathogenic bacteriumRalstonia solanacearumGMI1000 unveiled a polyketide synthase/nonribosomal peptide synthetase gene cluster putatively involved in siderophore biosynthesis. Insertional mutagenesis confirmed the respective locus to be operational under iron-deficient conditions and spurred the isolation of the associated natural product. Bioinformatic analyses of the gene cluster facilitated the structural characterization of this compound, which was subsequently identified as the antimycoplasma agent micacocidin. The metal-chelating properties of micacocidin were evaluated in competition experiments, and the cellular uptake of gallium-micacocidin complexes was demonstrated inR. solanacearumGMI1000, indicating a possible siderophore role. Comparative genomics revealed a conservation of the micacocidin gene cluster in defined, but globally dispersed phylotypes ofR. solanacearum.

scholarly journals Complete Genome Sequence of the Lignocellulose-Degrading Actinomycete Streptomyces albus CAS922

2020 ◽  
Vol 9 (21) ◽  
Author(s):  
Anna Tippelt ◽  
Markus Nett ◽  
M. Soledad Vela Gurovic
Keyword(s):  
Secondary Metabolites ◽  
Complete Genome Sequence ◽  
Sunflower Seed ◽  
Gene Clusters ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Carbohydrate Active Enzymes ◽  
Content Type ◽  
Bioactive Secondary Metabolites ◽  
Streptomyces Albus

ABSTRACT Streptomyces albus CAS922 was isolated from sunflower seed hulls. Its fully sequenced genome harbors a multitude of genes for carbohydrate-active enzymes, which likely facilitate growth on lignocellulosic biomass. Furthermore, the presence of 27 predicted biosynthetic gene clusters indicates a significant potential for the production of bioactive secondary metabolites.

scholarly journals Lysobacter enzymogenes Uses Two Distinct Cell-Cell Signaling Systems for Differential Regulation of Secondary-Metabolite Biosynthesis and Colony Morphology

2013 ◽  
Vol 79 (21) ◽  
pp. 6604-6616 ◽  
Author(s):  
Guoliang Qian ◽  
Yulan Wang ◽  
Yiru Liu ◽  
Feifei Xu ◽  
Ya-Wen He ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Cell Signaling ◽  
Secondary Metabolite ◽  
Colony Morphology ◽  
Content Type ◽  
Signaling Systems ◽  
Lysobacter Enzymogenes ◽  
Bioactive Secondary Metabolites ◽  
Secondary Metabolite Biosynthesis ◽  
First Time

ABSTRACTLysobacter enzymogenesis a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown inL. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time fromL. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis inL. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology ofL. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions inL. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis ofL. enzymogenes.

scholarly journals Upregulation of the Phthiocerol Dimycocerosate Biosynthetic Pathway by Rifampin-Resistant,rpoBMutant Mycobacterium tuberculosis

2012 ◽  
Vol 194 (23) ◽  
pp. 6441-6452 ◽  
Author(s):  
Gregory P. Bisson ◽  
Carolina Mehaffy ◽  
Corey Broeckling ◽  
Jessica Prenni ◽  
Dalin Rifat ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Secondary Metabolites ◽  
Gene Networks ◽  
Polyketide Synthase ◽  
Multidrug Resistant ◽  
Wild Type ◽  
Transcriptional Responses ◽  
Content Type ◽  
Resistant Tuberculosis ◽  
Phthiocerol Dimycocerosate

ABSTRACTMultidrug-resistant tuberculosis has emerged as a major threat to tuberculosis control. Phylogenetically related rifampin-resistant actinomycetes with mutations mapping to clinically dominantMycobacterium tuberculosismutations in therpoBgene show upregulation of gene networks encoding secondary metabolites. We compared the expressed proteomes and metabolomes of two fully drug-susceptible clinical strains ofM. tuberculosis(wild type) to those of their respective rifampin-resistant,rpoBmutant progeny strains with confirmed rifampin monoresistance following antitubercular therapy. Each of these strains was also used to infect gamma interferon- and lipopolysaccharide-activated murine J774A.1 macrophages to analyze transcriptional responses in a physiologically relevant model. BothrpoBmutants showed significant upregulation of the polyketide synthase genesppsA-ppsEanddrrA, which constitute an operon encoding multifunctional enzymes involved in the biosynthesis of phthiocerol dimycocerosate and other lipids inM. tuberculosis, but also of various secondary metabolites in related organisms, including antibiotics, such as erythromycin and rifamycins.ppsA(Rv2931),ppsB(Rv2932), andppsC(Rv2933) were also found to be upregulated more than 10-fold in the BeijingrpoBmutant strain relative to its wild-type parent strain during infection of activated murine macrophages. In addition, metabolomics identified precursors of phthiocerol dimycocerosate, but not the intact molecule itself, in greater abundance in bothrpoBmutant isolates. These data suggest thatrpoBmutation inM. tuberculosismay trigger compensatory transcriptional changes in secondary metabolism genes analogous to those observed in related actinobacteria. These findings may assist in developing novel methods to diagnose and treat drug-resistantM. tuberculosisinfections.

scholarly journals Diversity of Bacterial Biosynthetic Genes in Maritime Antarctica

2020 ◽  
Vol 8 (2) ◽  
pp. 279 ◽  
Author(s):  
Adriana Rego ◽  
António G. G. Sousa ◽  
João P. Santos ◽  
Francisco Pascoal ◽  
João Canário ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Polyketide Synthase ◽  
Amplicon Sequencing ◽  
Soil Samples ◽  
Chemical Diversity ◽  
Maritime Antarctica ◽  
Biosynthetic Genes ◽  
Peptide Synthetase ◽  
Drug Leads ◽  
Culture Dependent

Bacterial natural products (NPs) are still a major source of new drug leads. Polyketides (PKs) and non-ribosomal peptides (NRP) are two pharmaceutically important families of NPs and recent studies have revealed Antarctica to harbor endemic polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes, likely to be involved in the production of novel metabolites. Despite this, the diversity of secondary metabolites genes in Antarctica is still poorly explored. In this study, a computational bioprospection approach was employed to study the diversity and identity of PKS and NRPS genes to one of the most biodiverse areas in maritime Antarctica—Maxwell Bay. Amplicon sequencing of soil samples targeting ketosynthase (KS) and adenylation (AD) domains of PKS and NRPS genes, respectively, revealed abundant and unexplored chemical diversity in this peninsula. About 20% of AD domain sequences were only distantly related to characterized biosynthetic genes. Several PKS and NRPS genes were found to be closely associated to recently described metabolites including those from uncultured and candidate phyla. The combination of new approaches in computational biology and new culture-dependent and -independent strategies is thus critical for the recovery of the potential novel chemistry encoded in Antarctica microorganisms.

scholarly journals A Possible Role for Exocytosis in Aflatoxin Export in Aspergillus parasiticus

2010 ◽  
Vol 9 (11) ◽  
pp. 1724-1727 ◽  
Author(s):  
Anindya Chanda ◽  
Ludmila V. Roze ◽  
John E. Linz
Keyword(s):  
Secondary Metabolites ◽  
Experimental Evidence ◽  
Cytoplasmic Membrane ◽  
Aspergillus Parasiticus ◽  
Microscopic Analysis ◽  
Content Type ◽  
Growth Environment ◽  
Subcellular Organelles ◽  
Naturally Occurring ◽  
Bioactive Secondary Metabolites

ABSTRACT Filamentous fungi synthesize bioactive secondary metabolites with major human health and economic impacts. Little is known about the mechanisms that mediate the export of these metabolites to the cell exterior. Aspergillus parasiticus synthesizes aflatoxin, a secondary metabolite that is one of the most potent naturally occurring carcinogens known. We previously demonstrated that aflatoxin is synthesized and compartmentalized in specialized vesicles called aflatoxisomes and that these subcellular organelles also play a role in the export process. In the current study, we tested the hypothesis that aflatoxisomes fuse with the cytoplasmic membrane to facilitate the release of aflatoxin into the growth environment. Microscopic analysis of A. parasiticus grown under aflatoxin-inducing and non-aflatoxin-inducing conditions generated several lines of experimental evidence that supported the hypothesis. On the basis of the evidence, we propose that export of the mycotoxin aflatoxin in Aspergillus parasiticus occurs by exocytosis, and we present a model to illustrate this export mechanism.

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