Genome Sequence of Pigmented Siderophore-Producing Strain Serratia marcescens SM6

Abstract

Here we present a draft genome sequence of laboratory strain Serratia marcescens SM6. Using the antiSMASH 5.0 prediction tool, we identified five biosynthetic gene clusters involved in secondary metabolite production (two siderophores and a biosurfactant serratamolide, a glucosamine derivative, and a thiopeptide).

A Metabolomics and Molecular Networking Approach to Elucidate the Structures of Secondary Metabolites Produced by Serratia marcescens Strains

“…This work reports on the identification of four molecular families of secondary metabolites associated with Serratia species, including serratiochelin A ( 1 ), prodigiosin ( 2 ), serratamolide homologues ( 3 , 4 , 6 , 8 , 9 , 11 , 13 , and 18 ) and glucosamine derivative congeners ( 5 , 7 , 10 , 12 , 14 – 17 , and 19 – 21 ) (refer to Figures 2 – 5 ). The structures of prodigiosin and serratiochelin A have previously been elucidated, where prodigiosin was described as a tripyrrole red pigment with an alkyl substituent ( Figure 1A ; Lee et al, 2011 ) and serratiochelin A was described as a low-molecular weight siderophore with high affinity for iron ( Figure 1B ; Khilyas et al, 2019 ). The structure of several of the serratamolide and glucosamine derivative metabolites detected in the current study has previously been elucidated, with serratamolides generally described as lipopeptides of two L-serine residues (cyclic or open-ring) linked to two fatty acid chains ( Figure 1C ) and glucosamine derivatives described as glucose amines consisting of glucose, valine, a fatty acid chain and butyric acid ( Figure 1D ; Dwivedi et al, 2008 ; Eckelmann et al, 2018 ).…”

“…Although genome mining of the P1 and NP1 strains was not within the scope of this study, Khilyas et al (2019) sequenced the genome of a pigmented S. marcescens SM6 strain and used the antiSMASH 5.0 prediction tool to identify biosynthetic gene clusters involved in secondary metabolism within the strain. The authors identified five biosynthetic gene clusters involved in secondary metabolite production, including gene clusters responsible for the production of two siderophores (serratiochelin and chrysobactin), a thiopeptide, a serratamolide and a glucosamine derivative ( Khilyas et al, 2019 ). It is possible that the P1 and NP1 strains possess similar NRPS gene clusters as both strains were able to produce serratiochelin, serratamolides and glucosamine derivatives.…”

“…In recent years, pigmented and non-pigmented Serratia species have been recognized as a potential source of novel and structurally diverse bioactive secondary metabolites ( Soenens and Imperial, 2019 ). These bioactive metabolites include the pigment prodigiosin as well as biosurfactants (lipopeptides and glycolipids), glucosamine derivatives, oocydin A, siderophores (such as serratiochelin A; Figure 1A ), bacteriocins, carbapenem, althiomycin and serratin, among others ( Clements et al, 2019a ; Khilyas et al, 2019 ). Prodigiosin and serrawettins are two of the more extensively studied secondary metabolites due to their diverse biological activity and application as antitumor, antibacterial and antifungal agents ( Stankovic et al, 2014 ; Eckelmann et al, 2018 ; Clements et al, 2019a ).…”

“…Glucosamine derivatives (also referred to as N -butylglucosamine ester derivatives) are non-ribosomally synthesized diacylated peptoglucosamine derivatives ( Dwivedi et al, 2008 ; Khilyas et al, 2019 ) produced by Serratia species. They have not been extensively studied and to date only Dwivedi et al (2008) characterized glucosamine derivatives produced by a pigmented S. marcescens SHHRE645 strain.…”

The Serratia marcescens Siderophore Serratiochelin Is Necessary for Full Virulence during Bloodstream Infection

“…Genes associated with the synthesis of either serratiochelin or chrysobactin have been found in the sequenced genomes of other S. marcescens strains. For example, a clinical isolate of S. marcescens SM6 is predicted to produce serratiochelin and chrysobactin based on genetic identity to the schF (nonribosomal peptide synthetase [NRPS] in S. plymuthica V4) and cbsF (NRPS in Dickeya dadantii 3937) genes, respectively (25).…”