Microbes are outstanding producers of structurally diverse natural products, which serve as communication signals amongst microbes and/or between the microbial producer and a non-microbial host. The underlying biosynthetic pathways are often intertwined with complex cellular regulatory mechanisms to orchestrate the production levels and cellular responses related to these highly bioactive molecules.
This thematic issue aims to reflect recent advances in the field of natural product chemistry with a special focus on (new) natural products from microbial symbionts and/or symbiotic interactions, and insightful studies on their ecological functions, biosynthesis and evolution.
The articles within the topic series may cover 1) the identification and characterization of natural products from defined symbiotic microorganisms; 2) synthetic approaches towards microbial natural products serving as chemical communication signals in combination with ecological test (purpose: structure elucidation and functionalization), and 3) targeted analysis of their biosynthetic pathways to enhance structural diversity and an understanding of their biosynthesis.
Graphical Abstract
Figure 1: The structures of the bacterial sesterterpenes sestermobaraenes A–F (1–6) and sestermobaraol (7) fr...
Figure 2: Position-specific mass shift analyses for 1. Carbons that contribute fully to the formation of a fr...
Scheme 1: The EIMS fragmentation mechanisms for 1 explaining the formation of the fragment ions at m/z = 325,...
Scheme 2: The EIMS fragmentation mechanisms for 1 explaining the formation of fragment ions at m/z = 206 and ...
Figure 3: Position-specific mass shift analyses for 2. The carbons that contribute fully to the formation of ...
Scheme 3: The EIMS fragmentation mechanisms for 2 explaining the formation of the fragment ions at m/z = 325,...
Scheme 4: The EIMS fragmentation mechanisms for 2 explaining the formation of the fragment ions at m/z = 203 ...
Figure 4: The position-specific mass shift analyses for 3. Carbons that contribute fully to the formation of ...
Scheme 5: The EIMS fragmentation mechanisms for 3 explaining the formation of the fragment ions at m/z = 325,...
Scheme 6: The EIMS fragmentation mechanisms for 3 explaining the formation of the fragment ion at m/z = 206 a...
Graphical Abstract
Figure 1: Overview of the NRPs surfactin, plipastatin, bacillibactin, and iturin as well as the hybrid NRP-PK...
Figure 2: Overview of the experimental setup. A soil suspension, obtained from a soil sample, was used as an ...
Figure 3: The taxonomic summaries are showing the relative abundance of the most abundant genera for each rep...
Figure 4: Diversity analyses of the soil sample (“Soil”), 12 h preincubated soil suspensions (“Pre”), and unt...
Figure 5: Abundance ratios for each genus and replicate (points) in the control community compared to the WT-...
Figure 6: The relative abundance of Lysinibacillus in the untreated (“Control”) and treated mock communities ...
Figure 7: Growth curves of L. fusiformis M5 exposed to spent media from 48 h B. subtilis cultures and without...
Figure 8: Growth curves of L. fusiformis M5 exposed to different concentrations of surfactin, the highest con...
Figure 9: Overview on the biosynthetic pathways of surfactin (A), plipastatin (B), and bacillaene (C) produce...
Graphical Abstract
Scheme 1: Sulfur metabolism in bacteria from the roseobacter group. A) DMSP demethylation by DmdABCD, B) DMSP...
Figure 1: Total ion chromatograms of headspace extracts from A) C. marinus DSM 100036T, B) C. neptunius DSM 2...
Figure 2: Structures of the identified volatile compounds in the headspace extracts from six Celeribacter typ...
Figure 3: EI mass spectra of A) unlabeled 2-(methyldisulfanyl)benzothiazole (41) and of labeled 41 after feed...
Scheme 2: Synthesis of sulfur-containing compounds detected in the Celeribacter headspace extracts. A) Synthe...
Graphical Abstract
Scheme 1: Volatile allyl sulfides. A) Compounds known from garlic oil, B) mechanism of formation from alliin (...
Scheme 2: Degradation of DMSP by marine bacteria. A) Hydrolysis or lysis to DMS, B) demethylation pathway lea...
Scheme 3: Synthesis of DMSP derivatives.
Figure 1: Sulfur volatiles released by agar plate cultures of marine bacteria fed with DAllSP or AllMSP.
Figure 2: Total ion chromatograms of CLSA extracts obtained from feeding experiments with DAllSP fed to A) P....
Scheme 4: Proposed mechanisms for the formation of sulfur volatiles from DAllSP and AllMSP.
Figure 3: EI mass spectrum and fragmentation pattern of the unknown volatiles A) methyl 3-(allyldisulfanyl)pr...
Scheme 5: Synthesis of A) methyl 3-(allyldisulfanyl)propanoate (26) and B) methyl 3-(methylsulfonyl)propanoat...
Figure 4: Total ion chromatograms of CLSA extracts obtained from the feeding experiments with AllMSP fed to A...
Graphical Abstract
Figure 1: Untargeted comparative metabolomics using AP-SMALDI-HRMS highlighted metabolites involved in Ulva–b...
Figure 2: Identification of significant features associated with axenic or bacterial symbiont-associated alga ...
Figure 3: Visualisation of algae Ulva mutabilis grown under axenic conditions or with bacterial symbionts Ros...
Graphical Abstract
Figure 1: Chemical structures of sesquiterpenes emitted from endophytic fungi (Table 2) isolated from black poplar l...
Figure 2: Terpene synthase activity of CxTPS1 and CxTPS2. A) Genes were heterologously expressed in Escherich...
Figure 3: Dendrogram analysis (rooted tree) of CxTPS1 and CxTPS2 (bold) from Cladosporium sp. and characteriz...
Graphical Abstract
Figure 1: Schematic overview of fungal interactions in the environment. Fungi can be found in essentially all...
Figure 2: Fungal derived bioactive natural compounds with ecological and/or economic relevance.
Figure 3: Gliotoxin biosynthetic gene cluster and it major biosynthetic transformations: Gliotoxin (5) is the...
Figure 4: Amoebicidal secondary metabolites trypacidin and fumagillin of Aspergillus fumigatus.
Figure 5: Intermediates of the DHN-melanin biosynthesis in Aspergillus fumigatus.
Figure 6: Intermediates and products of the fumigaclavine C biosynthesis.
Figure 7: Bioactive secondary metabolites of Aspergillus fumigatus.
Figure 8: Helvolic acid gene cluster of A. fumigatus.