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 ◽  
...  

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.

2021 ◽  
Author(s):  
Wolfgang Hüttel ◽  
Michael Müller

Phenol coupling enzymes, especially laccases and CYP-enzymes create an enormous diversity of biarylic secondary metabolites in fungi, plants, and bacteria. The enzymes and the elucidation of the corresponding metabolic pathways are presented.


mSystems ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Kat Steinke ◽  
Omkar S. Mohite ◽  
Tilmann Weber ◽  
Ákos T. Kovács

ABSTRACT Microbes produce a plethora of secondary (or specialized) metabolites that, although not essential for primary metabolism, benefit them to survive in the environment, communicate, and influence cell differentiation. Biosynthetic gene clusters (BGCs), responsible for the production of these secondary metabolites, are readily identifiable on bacterial genome sequences. Understanding the phylogeny and distribution of BGCs helps us to predict the natural product synthesis ability of new isolates. Here, we examined 310 genomes from the Bacillus subtilis group, determined the inter- and intraspecies patterns of absence/presence for all BGCs, and assigned them to defined gene cluster families (GCFs). This allowed us to establish patterns in the distribution of both known and unknown products. Further, we analyzed variations in the BGC structures of particular families encoding natural products, such as plipastatin, fengycin, iturin, mycosubtilin, and bacillomycin. Our detailed analysis revealed multiple GCFs that are species or clade specific and a few others that are scattered within or between species, which will guide exploration of the chemodiversity within the B. subtilis group. Surprisingly, we discovered that partial deletion of BGCs and frameshift mutations in selected biosynthetic genes are conserved within phylogenetically related isolates, although isolated from around the globe. Our results highlight the importance of detailed genomic analysis of BGCs and the remarkable phylogenetically conserved erosion of secondary metabolite biosynthetic potential in the B. subtilis group. IMPORTANCE Members of the B. subtilis species complex are commonly recognized producers of secondary metabolites, among those, the production of antifungals, which makes them promising biocontrol strains. While there are studies examining the distribution of well-known secondary metabolites in Bacilli, intraspecies clade-specific distribution has not been systematically reported for the B. subtilis group. Here, we report the complete biosynthetic potential within the B. subtilis group to explore the distribution of the biosynthetic gene clusters and to reveal an exhaustive phylogenetic conservation of secondary metabolite production within Bacillus that supports the chemodiversity within this species complex. We identify that certain gene clusters acquired deletions of genes and particular frameshift mutations, rendering them inactive for secondary metabolite biosynthesis, a conserved genetic trait within phylogenetically conserved clades of certain species. The overview guides the assignment of the secondary metabolite production potential of newly isolated Bacillus strains based on genome sequence and phylogenetic relatedness.


2013 ◽  
Vol 79 (22) ◽  
pp. 6894-6902 ◽  
Author(s):  
Kelley A. Gallagher ◽  
Kristin Rauscher ◽  
Laura Pavan Ioca ◽  
Paul R. Jensen

ABSTRACTStreptomycesspecies dedicate a large portion of their genomes to secondary metabolite biosynthesis. A diverse and largely marine-derived lineage within this genus has been designated MAR4 and identified as a prolific source of hybrid isoprenoid (HI) secondary metabolites. These terpenoid-containing compounds are common in nature but rarely observed as bacterial secondary metabolites. To assess the phylogenetic diversity of the MAR4 lineage, complementary culture-based and culture-independent techniques were applied to marine sediment samples collected off the Channel Islands, CA. The results, including those from an analysis of publically available sequence data and strains isolated as part of prior studies, placed 40 new strains in the MAR4 clade, of which 32 originated from marine sources. When combined with sequences cloned from environmental DNA, 28 MAR4 operational taxonomic units (0.01% genetic distance) were identified. Of these, 82% consisted exclusively of either cloned sequences or cultured strains, supporting the complementarity of these two approaches. Chemical analyses of diverse MAR4 strains revealed the production of five different HI structure classes. All 21 MAR4 strains tested produced at least one HI class, with most strains producing from two to four classes. The two major clades within the MAR4 lineage displayed distinct patterns in the structural classes and the number and amount of HIs produced, suggesting a relationship between taxonomy and secondary metabolite production. The production of HI secondary metabolites appears to be a phenotypic trait of the MAR4 lineage, which represents an emerging model with which to study the ecology and evolution of HI biosynthesis.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Sandra C. K. Carlsen ◽  
Hans A. Pedersen ◽  
Niels H. Spliid ◽  
Inge S. Fomsgaard

White clover is frequently used as a leguminous cover crop, serving as green manure, and is also included with grasses in cattle feed mixtures. Numerous biological effects reported for clover cultivation have been attributed to the production of bioactive secondary metabolites. Thus far the presence in soil of bioactive secondary metabolites from clover has received limited attention. In this paper we examine for the first time the release of flavonoids both from field-grown white clover and from soil-incorporated white clover plants of flavonoids, as analyzed by LC-MS/MS. The dominant flavonoid aglycones were formononetin, medicarpin, and kaempferol. Soil-incorporated white clover plants generated high concentrations of the glycosides kaempferol-Rha-Xyl-Gal and quercetin-Xyl-Gal. Substantial amounts of kaempferol persisted in the soil for days while the other compounds were degraded faster. These compounds should be considered in future studies of soil fatigue, allelopathic activity, and possible environmental risks from extended clover cultivation.


2013 ◽  
Vol 8 (3) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Takashi Kamada ◽  
Charles Santhanaraju Vairappan

A Bornean red algal population of Laurencia simlis Nam et Saito was analyzed for its secondary metabolite composition. Seven compounds were identified: ent -1(10)-aristolen-9β-ol (1), (+)-aristolone (2), axinysone B (3), 9-aristolen-1α-ol (4), 2,3,5,6-tetrabromoindole (5), 1-methyl-2,3,5,6-tetrabromoindole (6), and 1-methyl-2,3,5-tribromoindole (7). Compound 1 was identified as a new optical isomer of 1(10)-aristolen-9β-ol. Compounds 1, 4 and 5 exhibited good antibacterial activity against antibiotic resistant clinical bacteria and cytotoxic effects against selected cancer cell lines.


2020 ◽  
Vol 9 (21) ◽  
Author(s):  
Anna Tippelt ◽  
Markus Nett ◽  
M. Soledad Vela Gurovic

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.


2012 ◽  
Vol 62 (Pt_5) ◽  
pp. 1171-1178 ◽  
Author(s):  
Niclas Engene ◽  
Erin C. Rottacker ◽  
Jan Kaštovský ◽  
Tara Byrum ◽  
Hyukjae Choi ◽  
...  

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.


2018 ◽  
Vol 84 (6) ◽  
Author(s):  
Nicholas A. Stella ◽  
Kimberly M. Brothers ◽  
Jake D. Callaghan ◽  
Angelina M. Passerini ◽  
Cihad Sigindere ◽  
...  

ABSTRACTSecondary metabolites are an important source of pharmaceuticals and key modulators of microbe-microbe interactions. The bacteriumSerratia marcescensis part of theEnterobacteriaceaefamily of eubacteria and produces a number of biologically active secondary metabolites. In this study, we screened for novel regulators of secondary metabolites synthesized by a clinical isolate ofS. marcescensand found mutations in a gene for an uncharacterized UmoB/IgaA family member here namedgumB. Mutation ofgumBconferred a severe loss of the secondary metabolites prodigiosin and serratamolide. ThegumBmutation conferred pleiotropic phenotypes, including altered biofilm formation, highly increased capsular polysaccharide production, and loss of swimming and swarming motility. These phenotypes corresponded to transcriptional changes infimA,wecA, andflhD. Unlike other UmoB/IgaA family members,gumBwas found to be not essential for growth inS. marcescens, yetigaAfromSalmonella enterica,yrfFfromEscherichia coli, and an uncharacterized predicted ortholog fromKlebsiella pneumoniaecomplemented thegumBmutant secondary metabolite defects, suggesting highly conserved function. These data support the idea that UmoB/IgaA family proteins are functionally conserved and extend the known regulatory influence of UmoB/IgaA family proteins to the control of competition-associated secondary metabolites and biofilm formation.IMPORTANCEIgaA/UmoB family proteins are found in members of theEnterobacteriaceaefamily of bacteria, which are of environmental and public health importance. IgaA/UmoB family proteins are thought to be inner membrane proteins that report extracellular stresses to intracellular signaling pathways that respond to environmental challenge. This study introduces a new member of the IgaA/UmoB family and demonstrates a high degree of functional similarity between IgaA/UmoB family proteins. Moreover, this study extends the phenomena controlled by IgaA/UmoB family proteins to include the biosynthesis of antimicrobial secondary metabolites.


2018 ◽  
Vol 84 (19) ◽  
Author(s):  
Brett C. Covington ◽  
Jeffrey M. Spraggins ◽  
Audrey E. Ynigez-Gutierrez ◽  
Zachary B. Hylton ◽  
Brian O. Bachmann

ABSTRACT Microorganisms within microbial communities respond to environmental challenges by producing biologically active secondary metabolites, yet the majority of these small molecules remain unidentified. We have previously demonstrated that secondary metabolite biosynthesis in actinomycetes can be activated by model environmental chemical and biological stimuli, and metabolites can be identified by comparative metabolomics analyses under different stimulus conditions. Here, we surveyed the secondary metabolite productivity of a group of 20 phylogenetically diverse actinobacteria isolated from hypogean (cave) environments by applying a battery of stimuli consisting of exposure to antibiotics, metals, and mixed microbial culture. Comparative metabolomics was used to reveal secondary metabolite responses from stimuli. These analyses revealed substantial changes in global metabolomic dynamics, with over 30% of metabolomic features increasing more than 10-fold under at least one stimulus condition. Selected features were isolated and identified via nuclear magnetic resonance (NMR), revealing several known secondary metabolite families, including the tetarimycins, aloesaponarins, hypogeamicins, actinomycins, and propeptins. One prioritized metabolite was identified to be a previously unreported aminopolyol polyketide, funisamine, produced by a cave isolate of Streptosporangium when exposed to mixed culture. The production of funisamine was most significantly increased in mixed culture with Bacillus species. The biosynthetic gene cluster responsible for the production of funisamine was identified via genomic sequencing of the producing strain, Streptosporangium sp. strain KDCAGE35, which facilitated a deduction of its biosynthesis. Together, these data demonstrate that comparative metabolomics can reveal the stimulus-induced production of natural products from diverse microbial phylogenies. IMPORTANCE Microbial secondary metabolites are an important source of biologically active and therapeutically relevant small molecules. However, much of this active molecular diversity is challenging to access due to low production levels or difficulty in discerning secondary metabolites within complex microbial extracts prior to isolation. Here, we demonstrate that ecological stimuli increase secondary metabolite production in phylogenetically diverse actinobacteria isolated from understudied hypogean environments. Additionally, we show that comparative metabolomics linking stimuli to metabolite response data can effectively reveal secondary metabolites within complex biological extracts. This approach highlighted secondary metabolites in almost all observed natural product classes, including low-abundance analogs of biologically relevant metabolites, as well as a new linear aminopolyol polyketide, funisamine. This study demonstrates the generality of activating stimuli to potentiate secondary metabolite production across diverse actinobacterial genera.


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