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Journal of Virology Dec 2012A virulent bacteriophage (ΦMAM1) that infects Serratia plymuthica was isolated from the natural environment and characterized. Genomic sequence analysis revealed a...
A virulent bacteriophage (ΦMAM1) that infects Serratia plymuthica was isolated from the natural environment and characterized. Genomic sequence analysis revealed a circular double-stranded DNA sequence of 157,834 bp, encoding 198 proteins and 3 tRNAs. The ΦMAM1 genome shows high homology to previously reported ViI-like enterobacterial bacteriophage genomes.
Topics: Bacteriophages; Genome, Viral; Molecular Sequence Data; Serratia
PubMed: 23166269
DOI: 10.1128/JVI.02702-12 -
Genome Announcements May 2016The rhizobacterium Serratia plymuthica A153 is a Gram-negative bacterium belonging to the family Enterobacteriaceae Here, we present the genome sequence of this strain,...
The rhizobacterium Serratia plymuthica A153 is a Gram-negative bacterium belonging to the family Enterobacteriaceae Here, we present the genome sequence of this strain, which produces multiple bioactive secondary metabolites, including the halogenated macrolide oocydin A, the polyamino antibiotic zeamine, and the bacterial acetyl-CoA carboxylase inhibitor andrimid.
PubMed: 27198016
DOI: 10.1128/genomeA.00373-16 -
Frontiers in Microbiology 2020The Chinese cordyceps is a unique and valuable parasitic complex of / ghost moths and the fungus for medicine and health foods from the Tibetan Plateau. During...
The Chinese cordyceps is a unique and valuable parasitic complex of / ghost moths and the fungus for medicine and health foods from the Tibetan Plateau. During artificial cultivation of Chinese cordyceps, the induction of blastospores into hyphae is a prerequisite for mummification of the infected larvae. To explore the microbial involvement in the induction of mycelia-blastospore transition, the microbiota of the hemolymph and gut from larvae with or without injected blastospores were investigated by culture-dependent and -independent methods. Twenty-five culturable bacterial species and 14 fungal species, together with 537 bacterial operational taxonomic units (OTUs) and 218 fungal OTUs, were identified from the hemolymph and gut of samples from five stages including living larvae without injected fungi (A) or with high blastospore load (B), mummifying larvae without mycelia coating (C), freshly mummifying larvae coated with mycelia (D), and completely mummified larvae with mycelia (E). Two culturable bacterial species (), and 47 bacterial and 15 fungal OTUs were considered as shared species. The uninfected larval hemolymph contained 13 culturable bacterial species but no fungal species, together with 164 bacterial and 73 fungal OTUs. To our knowledge, this is the first study to detect large bacterial communities from the hemolymph of healthy insect larvae. When the living larvae contained high blastospore load, the culturable bacterial community was sharply inhibited in the hemolymph but the bacterial and fungal community greatly increased in the gut. In general, high blastospore load increased bacterial diversity but sharply decreased fungal diversity in the hemolymph and gut by OTUs. The bacterial loads of four culturable species ( sp., , ) increased significantly and . and spp. became dominant microbes, when the infected larvae became mummified, indicating their possible involvement in the larval mummification process. The discovery of many opportunistic pathogenic bacteria in the hemolymph of the healthy larvae, the larval microbial diversity influenced by challenge and the involvement of dominant bacteria during larval mummification process provide new insight into the infection and mummification mechanisms of in its hosts.
PubMed: 33343519
DOI: 10.3389/fmicb.2020.577268 -
Frontiers in Microbiology 2015Soil bacteria can be prolific producers of secondary metabolites and other biologically active compounds of economic and clinical importance. These natural products are...
Soil bacteria can be prolific producers of secondary metabolites and other biologically active compounds of economic and clinical importance. These natural products are often synthesized by large multi-enzyme complexes such as polyketide synthases (PKSs) or non-ribosomal peptide synthases (NRPSs). The plant-associated Gram-negative bacterium, Serratia plymuthica A153, produces several secondary metabolites and is capable of killing the nematode worm Caenorhabditis elegans; a commonly used model for the study of bacterial virulence. In this study, we show that disruption of the hybrid PKS/NRPS zeamine (zmn) gene cluster results in the attenuation of "fast-killing" of C. elegans, indicating that zeamine has nematicidal activity. C. elegans also exhibits age-dependent susceptibility to zeamine, with younger worms being most sensitive to the bioactive molecule. The zmn gene cluster is widely distributed within Serratia and phytopathogenic Dickeya species and investigation of strains harboring the zmn gene cluster showed that several of them are highly virulent in C. elegans. Zeamine was described previously as a phytotoxin and broad-spectrum antibacterial compound. In addition to its nematicidal properties, we show here that zeamine can also kill Saccharomyces cerevisiae and Schizosaccharomyces pombe. The expression of the zmn gene cluster and regulation of zeamine production were also investigated. Transcription of the cluster was growth phase-dependent, and was modulated by the post-transcriptional RNA chaperone, Hfq. The results of this study show that zeamine is a highly toxic molecule with little, or no, apparent host specificity in very diverse biological systems. In its current form, zeamine(s) may be useful as a lead compound suitable for chemical modification and structure-activity assays. However, because of widespread non-selective toxicity in multiple bioassays, unmodified zeamine(s) is unlikely to be suitable as a therapeutic antibiotic.
PubMed: 25767467
DOI: 10.3389/fmicb.2015.00137 -
Scientific Reports Nov 2018Microorganisms release a plethora of volatile secondary metabolites. Up to now, it has been widely accepted that these volatile organic compounds are produced and...
Microorganisms release a plethora of volatile secondary metabolites. Up to now, it has been widely accepted that these volatile organic compounds are produced and emitted as a final product by a single organism e.g. a bacterial cell. We questioned this commonly assumed perspective and hypothesized that in diversely colonized microbial communities, bacterial cells can passively interact by emitting precursors which non-enzymatically react to form the active final compound. This hypothesis was inspired by the discovery of the bacterial metabolite schleiferon A. This bactericidal volatile compound is formed by a non-enzymatic reaction between acetoin and 2-phenylethylamine. Both precursors are released by Staphylococcus schleiferi cells. In order to provide evidence for our hypothesis that these precursors could also be released by bacterial cells of different species, we simultaneously but separately cultivated Serratia plymuthica 4Rx13 and Staphylococcus delphini 20771 which held responsible for only one precursor necessary for schleiferon A formation, respectively. By mixing their headspace, we demonstrated that these two species were able to deliver the active principle schleiferon A. Such a joint formation of a volatile secondary metabolite by different bacterial species has not been described yet. This highlights a new aspect of interpreting multispecies interactions in microbial communities as not only direct interactions between species might determine and influence the dynamics of the community. Events outside the cell could lead to the appearance of new compounds which could possess new community shaping properties.
Topics: Acetoin; Anti-Infective Agents; Antibiosis; Butanones; Microbiota; Phenethylamines; Quorum Sensing; Serratia; Species Specificity; Staphylococcus; Volatile Organic Compounds
PubMed: 30442919
DOI: 10.1038/s41598-018-35341-3 -
EFSA Journal. European Food Safety... Apr 2021The food enzyme isomaltulose synthase (sucrose glucosylmutase; EC 5.4.99.11) is produced with strain Z12A by BENEO-Palatinit GmbH. The food enzyme is used only in the...
The food enzyme isomaltulose synthase (sucrose glucosylmutase; EC 5.4.99.11) is produced with strain Z12A by BENEO-Palatinit GmbH. The food enzyme is used only in the form of an immobilised preparation of non-viable cells for the production of isomaltulose. Residual amounts of total organic solids (TOS) are removed by the purification steps applied during the production of isomaltulose consequently, dietary exposure was not calculated. Genotoxicity tests did not indicate safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,011 mg TOS/kg body weight (bw) per day, the highest dose tested. Similarity of the amino acid sequence of the enzyme to those of known allergens was searched and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood of such reactions to occur is considered to be low. Based on the data provided, the use of an immobilised food enzyme and the removal of TOS during the production of isomaltulose the Panel concluded that this food enzyme preparation does not give rise to safety concerns under the intended conditions of use.
PubMed: 33859733
DOI: 10.2903/j.efsa.2021.6432 -
Infection and Immunity Oct 1982Strains of Serratia marcescens, Serratia liquefaciens, Serratia marinorubra, and Serratia plymuthica produced one or more of the following hemagglutinins (HAs):...
Strains of Serratia marcescens, Serratia liquefaciens, Serratia marinorubra, and Serratia plymuthica produced one or more of the following hemagglutinins (HAs): mannose-sensitive HA and mannose-resistant K-HA (MR/K-HA) and P-HA (MR/P-HA) (J. P. Duguid and D. C. Old, in E. H. Beachey (ed.), Bacterial adherence, vol. 6., p. 185-217, 1980). Most strains (82%) were multiply hemagglutinating. The properties of the three HAs are described. Each HA was associated with a distinct type of fimbria: mannose-sensitive HA with type 1 fimbriae. MR/K-HA with type 3 fimbriae, and MR/P-HA with a new type of thin fimbriae provisionally called MR/P fimbriae. This is the first report of the production of MR/P-HA and MR/P fimbriae by Serratia species. The range of Serratia HAs, which may reflect in vivo colonization potential, is more complex than previously reported.
Topics: Fimbriae, Bacterial; Hemagglutination; Hemagglutinins; Mannose; Microscopy, Electron; Serratia; Serratia marcescens
PubMed: 6128303
DOI: 10.1128/iai.38.1.306-315.1982 -
Applied and Environmental Microbiology Nov 2006We have previously characterized the N-acyl-l-homoserine lactone-based quorum-sensing system of the biofilm isolate Serratia plymuthica RVH1. Here we investigated the...
We have previously characterized the N-acyl-l-homoserine lactone-based quorum-sensing system of the biofilm isolate Serratia plymuthica RVH1. Here we investigated the role of quorum sensing and of quorum-sensing-dependent production of an antimicrobial compound (AC) on biofilm formation by RVH1 and on the cocultivation of RVH1 and Escherichia coli in planktonic cultures or in biofilms. Biofilm formation of S. plymuthica was not affected by the knockout of splI or splR, the S. plymuthica homologs of the luxI or luxR quorum-sensing gene, respectively, or by the knockout of AC production. E. coli grew well in mixed broth culture with RVH1 until the latter reached 8.5 to 9.5 log CFU/ml, after which the E. coli colony counts steeply declined. In comparison, only a very small decline occurred in cocultures with the S. plymuthica AC-deficient and splI mutants. Complementation with exogenous N-hexanoyl-l-homoserine lactone rescued the wild-type phenotype of the splI mutant. The splR knockout mutant also induced a steep decline of E. coli, consistent with its proposed function as a repressor of quorum-sensing-regulated genes. The numbers of E. coli in 3-day-old mixed biofilms followed a similar pattern, being higher with S. plymuthica deficient in SplI or AC production than with wild-type S. plymuthica, the splR mutant, or the splI mutant in the presence of N-hexanoyl-l-homoserine lactone. Confocal laser scanning microscopic analysis of mixed biofilms established with strains producing different fluorescent proteins showed that E. coli microcolonies were less developed in the presence of RVH1 than in the presence of the AC-deficient mutant.
Topics: 4-Butyrolactone; Anti-Bacterial Agents; Bacterial Proteins; Biofilms; Colony Count, Microbial; Escherichia coli; Gene Expression Regulation, Bacterial; Plankton; Serratia; Signal Transduction
PubMed: 16997989
DOI: 10.1128/AEM.01708-06 -
Applied and Environmental Microbiology Oct 2014Members of the enterobacterial genus Serratia are ecologically widespread, and some strains are opportunistic human pathogens. Bacteriophage ϕMAM1 was isolated on...
Bacteriophage ϕMAM1, a viunalikevirus, is a broad-host-range, high-efficiency generalized transducer that infects environmental and clinical isolates of the enterobacterial genera Serratia and Kluyvera.
Members of the enterobacterial genus Serratia are ecologically widespread, and some strains are opportunistic human pathogens. Bacteriophage ϕMAM1 was isolated on Serratia plymuthica A153, a biocontrol rhizosphere strain that produces the potently bioactive antifungal and anticancer haterumalide oocydin A. The ϕMAM1 phage is a generalized transducing phage that infects multiple environmental and clinical isolates of Serratia spp. and a rhizosphere strain of Kluyvera cryocrescens. Electron microscopy allowed classification of ϕMAM1 in the family Myoviridae. Bacteriophage ϕMAM1 is virulent, uses capsular polysaccharides as a receptor, and can transduce chromosomal markers at frequencies of up to 7 × 10(-6) transductants per PFU. We also demonstrated transduction of the complete 77-kb oocydin A gene cluster and heterogeneric transduction of a plasmid carrying a type III toxin-antitoxin system. These results support the notion of the potential ecological importance of transducing phages in the acquisition of genes by horizontal gene transfer. Phylogenetic analyses grouped ϕMAM1 within the ViI-like bacteriophages, and genomic analyses revealed that the major differences between ϕMAM1 and other ViI-like phages arise in a region encoding the host recognition determinants. Our results predict that the wider genus of ViI-like phages could be efficient transducing phages, and this possibility has obvious implications for the ecology of horizontal gene transfer, bacterial functional genomics, and synthetic biology.
Topics: Bacteriophages; Gene Expression Regulation, Viral; Gene Transfer, Horizontal; Genome, Viral; Host Specificity; Humans; Kluyvera; Lactones; Microscopy, Electron; Multigene Family; Mutation; Myoviridae; Phylogeny; Plasmids; Regulatory Sequences, Nucleic Acid; Rhizosphere; Serratia; Transduction, Genetic; Viral Structural Proteins
PubMed: 25107968
DOI: 10.1128/AEM.01546-14 -
Frontiers in Microbiology 2016Bacteria release a plethora of volatile organic compounds, including compounds with extraordinary structures. Sodorifen (IUPAC name:...
Bacteria release a plethora of volatile organic compounds, including compounds with extraordinary structures. Sodorifen (IUPAC name: 1,2,4,5,6,7,8-heptamethyl-3-methylenebicyclo[3.2.1]oct-6-ene) is a recently identified and unusual volatile hydrocarbon that is emitted by the rhizobacterium Serratia plymuthica 4R×13. Sodorifen comprises a bicyclic ring structure solely consisting of carbon and hydrogen atoms, where every carbon atom of the skeleton is substituted with either a methyl or a methylene group. This unusual feature of sodorifen made a prediction of its biosynthetic origin very difficult and so far its biosynthesis is unknown. To unravel the biosynthetic pathway we performed genome and transcriptome analyses to identify candidate genes. One knockout mutant (SOD_c20750) showed the desired negative sodorifen phenotype. Here it was shown for the first time that this gene is indispensable for the synthesis of sodorifen and strongly supports the hypothesis that sodorifen descends from the terpene metabolism. SOD_c20750 is the first bacterial terpene cyclase isolated from Serratia spp. and Enterobacteriales. Homology modeling revealed a 3D structure, which exhibits a functional role of amino acids for intermediate cation stabilization (W325) and putative proton acception (Y332). Moreover, the size and hydrophobicity of the active site strongly indicates that indeed the enzyme may catalyze the unusual compound sodorifen.
PubMed: 27242752
DOI: 10.3389/fmicb.2016.00737