scholarly journals A global survey of specialized metabolic diversity encoded in bacterial genomes

2021 ◽  
Author(s):  
Athina Gavriilidou ◽  
Satria A Kautsar ◽  
Nestor Zaburannyi ◽  
Daniel Krug ◽  
Rolf Mueller ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Evolutionary History ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
Metabolic Diversity ◽  
Bacterial Genomes ◽  
Biosynthetic Gene Clusters ◽  
Taxonomic Rank ◽  
New Antibiotics ◽  
Biosynthetic Machinery

Bacterial secondary metabolites have been studied for decades for their usefulness as drugs, such as antibiotics. However, the identification of new structures has been decelerating, in part due to rediscovery of known compounds. Meanwhile, multi-resistant pathogens continue to emerge, urging the need for new antibiotics. It is unclear how much chemical diversity exists in Nature and whether discovery efforts should be focused on established antibiotic producers or rather on understudied taxa. Here, we surveyed around 170,000 bacterial genomes as well as several thousands of Metagenome Assembled Genomes (MAGs) for their diversity in Biosynthetic Gene Clusters (BGCs) known to encode the biosynthetic machinery for producing secondary metabolites. We used two distinct algorithms to provide a global overview of the biosynthetic diversity present in the sequenced part of the bacterial kingdom. Our results indicate that only 3% of genomic potential for natural products has been experimentally discovered. We connect the emergence of most biosynthetic diversity in evolutionary history close to the taxonomic rank of genus. Despite enormous differences in potential among taxa, we identify Streptomyces as by far the most biosynthetically diverse based on currently available data. Simultaneously, our analysis highlights multiple promising high-producing taxas that have thus far escaped investigation.

scholarly journals Use of Permanent Wall-Deficient Cells as a System for the Discovery of New-to-Nature Metabolites

2020 ◽  
Vol 8 (12) ◽  
pp. 1897
Author(s):  
Shraddha Shitut ◽  
Güniz Özer Bergman ◽  
Alexander Kros ◽  
Daniel E. Rozen ◽  
Dennis Claessen
Keyword(s):  
Cell Wall ◽  
Secondary Metabolites ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
Biosynthetic Gene Clusters ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Genome Recombination ◽  
Antibiotic Discovery ◽  
Insight Into

Filamentous actinobacteria are widely used as microbial cell factories to produce valuable secondary metabolites, including the vast majority of clinically relevant antimicrobial compounds. Secondary metabolites are typically encoded by large biosynthetic gene clusters, which allow for a modular approach to generating diverse compounds through recombination. Protoplast fusion is a popular method for whole genome recombination that uses fusion of cells that are transiently wall-deficient. This process has been applied for both inter- and intraspecies recombination. An important limiting step in obtaining diverse recombinants from fused protoplasts is regeneration of the cell wall, because this forces the chromosomes from different parental lines to segregate, thereby preventing further recombination. Recently, several labs have gained insight into wall-deficient bacteria that have the ability to proliferate without their cell wall, known as L-forms. Unlike protoplasts, L-forms can stably maintain multiple chromosomes over many division cycles. Fusion of such L-forms would potentially allow cells to express genes from both parental genomes while also extending the time for recombination, both of which can contribute to an increased chemical diversity. Here, we present a perspective on how L-form fusion has the potential to become a platform for novel compound discovery and may thus help to overcome the antibiotic discovery void.

scholarly journals IMG-ABC v.5.0: an update to the IMG/Atlas of Biosynthetic Gene Clusters Knowledgebase

2019 ◽  
Author(s):  
Krishnaveni Palaniappan ◽  
I-Min A Chen ◽  
Ken Chu ◽  
Anna Ratner ◽  
Rekha Seshadri ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Secondary Metabolism ◽  
Gene Clusters ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Microbial Genomes ◽  
Initial Release ◽  
Systematic Identification ◽  
Biomedical Potential ◽  
Biosynthetic Machinery

Abstract Microbial secondary metabolism is a reservoir of bioactive compounds of immense biotechnological and biomedical potential. The biosynthetic machinery responsible for the production of these secondary metabolites (SMs) (also called natural products) is often encoded by collocated groups of genes called biosynthetic gene clusters (BGCs). High-throughput genome sequencing of both isolates and metagenomic samples combined with the development of specialized computational workflows is enabling systematic identification of BGCs and the discovery of novel SMs. In order to advance exploration of microbial secondary metabolism and its diversity, we developed the largest publicly available database of predicted BGCs combined with experimentally verified BGCs, the Integrated Microbial Genomes Atlas of Biosynthetic gene Clusters (IMG-ABC) (https://img.jgi.doe.gov/abc-public). Here we describe the first major content update of the IMG-ABC knowledgebase, since its initial release in 2015, refreshing the BGC prediction pipeline with the latest version of antiSMASH (v5) as well as presenting the data in the context of underlying environmental metadata sourced from GOLD (https://gold.jgi.doe.gov/). This update has greatly improved the quality and expanded the types of predicted BGCs compared to the previous version.

scholarly journals A Glossary for Chemical Approaches towards Unlocking the Trove of Metabolic Treasures in Actinomycetes

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 142
Author(s):  
Jianye Zhang ◽  
Heba Ali Hassan ◽  
Usama Ramadan Abdelmohsen ◽  
Eman Maher Zahran
Keyword(s):  
Secondary Metabolites ◽  
Gene Clusters ◽  
Physiological Signals ◽  
Genomic Sequencing ◽  
Biosynthetic Gene ◽  
Chemical Signaling ◽  
Sequencing Data ◽  
Biosynthetic Gene Clusters ◽  
New Antibiotics ◽  
New Metabolites

Actinobacterial natural products showed a critical basis for the discovery of new antibiotics as well as other lead secondary metabolites. Varied environmental and physiological signals touch the antibiotic machinery that faced a serious decline in the last decades. The reason was exposed by genomic sequencing data, which revealed that Actinomycetes harbor a large portion of silent biosynthetic gene clusters in their genomes that encrypt for secondary metabolites. These gene clusters are linked with a great reservoir of yet unknown molecules, and arranging them is considered a major challenge for biotechnology approaches. In the present paper, we discuss the recent strategies that have been taken to augment the yield of secondary metabolites via awakening these cryptic genes in Actinomycetes with emphasis on chemical signaling molecules used to induce the antibiotics biosynthesis. The rationale, types, applications and mechanisms are discussed in detail, to reveal the productive path for the unearthing of new metabolites, covering the literature until the end of 2020.

scholarly journals Recapitulation of the evolution of biosynthetic gene clusters reveals hidden chemical diversity on bacterial genomes

2015 ◽  
Author(s):  
Pablo Cruz-Morales ◽  
Christian E. Martínez-Guerrero ◽  
Marco A. Morales-Escalante ◽  
Luis Yáñez-Guerra ◽  
Johannes Florian Kopp ◽  
...  
Keyword(s):  
Natural Products ◽  
Chemical Space ◽  
Streptomyces Coelicolor ◽  
Genome Mining ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Chemical Diversity ◽  
Biosynthetic Gene ◽  
Bacterial Genomes ◽  
Biosynthetic Gene Clusters

AbstractNatural products have provided humans with antibiotics for millennia. However, a decline in the pace of chemical discovery exerts pressure on human health as antibiotic resistance spreads. The empirical nature of current genome mining approaches used for natural products research limits the chemical space that is explored. By integration of evolutionary concepts related to emergence of metabolism, we have gained fundamental insights that are translated into an alternative genome mining approach, termed EvoMining. As the founding assumption of EvoMining is the evolution of enzymes, we solved two milestone problems revealing unprecedented conversions. First, we report the biosynthetic gene cluster of the ‘orphan’ metabolite leupeptin in Streptomyces roseus. Second, we discover an enzyme involved in formation of an arsenic-carbon bond in Streptomyces coelicolor and Streptomyces lividans. This work provides evidence that bacterial chemical repertoire is underexploited, as well as an approach to accelerate the discovery of novel antibiotics from bacterial genomes.

scholarly journals Global biogeographic sampling of bacterial secondary metabolism

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Zachary Charlop-Powers ◽  
Jeremy G Owen ◽  
Boojala Vijay B Reddy ◽  
Melinda A Ternei ◽  
Denise O Guimarães ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Genome Sequencing ◽  
Geographic Distance ◽  
Gene Clusters ◽  
Natural World ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Road Map ◽  
Two Factors ◽  
Natural Products Discovery

Recent bacterial (meta)genome sequencing efforts suggest the existence of an enormous untapped reservoir of natural-product-encoding biosynthetic gene clusters in the environment. Here we use the pyro-sequencing of PCR amplicons derived from both nonribosomal peptide adenylation domains and polyketide ketosynthase domains to compare biosynthetic diversity in soil microbiomes from around the globe. We see large differences in domain populations from all except the most proximal and biome-similar samples, suggesting that most microbiomes will encode largely distinct collections of bacterial secondary metabolites. Our data indicate a correlation between two factors, geographic distance and biome-type, and the biosynthetic diversity found in soil environments. By assigning reads to known gene clusters we identify hotspots of biomedically relevant biosynthetic diversity. These observations not only provide new insights into the natural world, they also provide a road map for guiding future natural products discovery efforts.

Future directions for the discovery of antibiotics from actinomycete bacteria

2017 ◽  
Vol 1 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Rebecca Devine ◽  
Matthew I. Hutchings ◽  
Neil A. Holmes
Keyword(s):  
New Technologies ◽  
Gene Clusters ◽  
Biosynthetic Gene Clusters ◽  
Future Directions ◽  
Streptomyces Species ◽  
Genus Streptomyces ◽  
New Antibiotics ◽  
The Uk ◽  
Almost All ◽  
New Generation

Antimicrobial resistance (AMR) is a growing societal problem, and without new anti-infective drugs, the UK government-commissioned O'Neil report has predicted that infectious disease will claim the lives of an additional 10 million people a year worldwide by 2050. Almost all the antibiotics currently in clinical use are derived from the secondary metabolites of a group of filamentous soil bacteria called actinomycetes, most notably in the genus Streptomyces. Unfortunately, the discovery of these strains and their natural products (NPs) peaked in the 1950s and was then largely abandoned, partly due to the repeated rediscovery of known strains and compounds. Attention turned instead to rational target-based drug design, but this was largely unsuccessful and few new antibiotics have made it to clinic in the last 60 years. In the early 2000s, however, genome sequencing of the first Streptomyces species reinvigorated interest in NP discovery because it revealed the presence of numerous cryptic NP biosynthetic gene clusters that are not expressed in the laboratory. Here, we describe how the use of new technologies, including improved culture-dependent and -independent techniques, combined with searching underexplored environments, promises to identify a new generation of NP antibiotics from actinomycete bacteria.

scholarly journals Phytoplankton trigger the production of cryptic metabolites in the marine actinobacteria Salinispora tropica

2020 ◽  
Author(s):  
Audam Chhun ◽  
Despoina Sousoni ◽  
Maria del Mar Aguiló-Ferretjans ◽  
Lijiang Song ◽  
Christophe Corre ◽  
...  
Keyword(s):  
Natural Products ◽  
Secondary Metabolites ◽  
Antibiotic Production ◽  
Antimicrobial Effect ◽  
Gene Clusters ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Marine Actinobacteria ◽  
Salinispora Tropica ◽  
Eukaryotic Phytoplankton

AbstractBacteria from the Actinomycete family are a remarkable source of natural products with pharmaceutical potential. The discovery of novel molecules from these organisms is, however, hindered because most of the biosynthetic gene clusters (BGCs) encoding these secondary metabolites are cryptic or silent and are referred to as orphan BGCs. While co-culture has proven to be a promising approach to unlock the biosynthetic potential of many microorganisms by activating the expression of these orphan BGCs, it still remains an underexplored technique. The marine actinobacteria Salinispora tropica, for instance, produces valuable compounds such as the anti-cancer molecule salinosporamide A but half of its putative BGCs are still orphan. Although previous studies have looked into using marine heterotrophs to induce orphan BGCs in Salinispora, the potential impact of co-culturing marine phototrophs with Salinispora has yet to be investigated. Following the observation of clear antimicrobial phenotype of the actinobacterium on a range of phytoplanktonic organisms, we here report the discovery of novel cryptic secondary metabolites produced by S. tropica in response to its co-culture with photosynthetic primary producers. An approach combining metabolomics and proteomics revealed that the photosynthate released by phytoplankton influences the biosynthetic capacities of S. tropica with both production of new molecules and the activation of orphan BGCs. Our work pioneers the use of phototrophs as a promising strategy to accelerate the discovery of novel natural products from actinobacteria.ImportanceThe alarming increase of antimicrobial resistance has generated an enormous interest in the discovery of novel active compounds. The isolation of new microbes to untap novel natural products is currently hampered because most biosynthetic gene clusters (BGC) encoded by these microorganisms are not expressed under standard laboratory conditions, i.e. mono-cultures. Here we show that co-culturing can be an easy way for triggering silent BGC. By combining state-of-the-art metabolomics and high-throughput proteomics, we characterized the activation of cryptic metabolites and silent biosynthetic gene clusters in the marine actinobacteria Salinispora tropica by the presence of phytoplankton photosynthate. We further suggest a mechanistic understanding of the antimicrobial effect this actinobacterium has on a broad range of prokaryotic and eukaryotic phytoplankton species and reveal a promising candidate for antibiotic production.

scholarly journals Discovery of Cyanobacterial Natural Products Containing Fatty Acid Residues

2020 ◽  
Author(s):  
Sandra A. C. Figueiredo ◽  
Marco Preto ◽  
Gabriela Moreira ◽  
Teresa P. Martins ◽  
Kathleen Abt ◽  
...  
Keyword(s):  
Natural Products ◽  
Fatty Acid ◽  
Isotope Labeling ◽  
Gene Clusters ◽  
New Drugs ◽  
Beta Oxidation ◽  
Bacterial Genomes ◽  
Biosynthetic Gene Clusters ◽  
Apparent Lack ◽  
Massive Sequencing

Natural products have an important role in several human activities, most notably as sources of new drugs. In recent years, massive sequencing and annotation of bacterial genomes has revealed an unexpectedly large number of secondary metabolite biosynthetic gene clusters whose products are yet to be discovered. For example, cyanobacterial genomes contain a large number of gene clusters that likely incorporate fatty acid-derived moieties, but for most cases we lack the knowledge and tools to effectively predict or detect the encoded natural products. Here, we exploit the apparent lack of a functional beta-oxidation pathway in cyanobacteria to achieve efficient stable-isotope labeling of their fatty acid-derived lipidome. We show that supplementation of cyanobacterial cultures with deuterated fatty acids can be used to easily detect natural product signatures in individual strains. The utility of this strategy is demonstrated in two cultured cyanobacteria by uncovering analogues of the multidrug-resistance reverting hapalosin, and novel, cytotoxic, lactylate-nocuolin A hybrids – the nocuolactylates.

scholarly journals Phylogenetic Distribution of Secondary Metabolites in the Bacillus subtilis Species Complex

mSystems ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Kat Steinke ◽  
Omkar S. Mohite ◽  
Tilmann Weber ◽  
Ákos T. Kovács
Keyword(s):  
Bacillus Subtilis ◽  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
Species Complex ◽  
Gene Clusters ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Content Type ◽  
Frameshift Mutations ◽  
Metabolite Production

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.

scholarly journals Uncovering the unexplored diversity of thioamidated ribosomal peptides in Actinobacteria using the RiPPER genome mining tool

2018 ◽  
Author(s):  
Javier Santos-Aberturas ◽  
Govind Chandra ◽  
Luca Frattaruolo ◽  
Rodney Lacret ◽  
Thu H. Pham ◽  
...  
Keyword(s):  
Genome Mining ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
Bioactive Molecules ◽  
Post Translational Modification ◽  
Biosynthetic Gene Clusters ◽  
New Family ◽  
The Family ◽  
Modified Peptides ◽  
Mining Tool

ABSTRACTThe rational discovery of new specialized metabolites by genome mining represents a very promising strategy in the quest for new bioactive molecules. Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a major class of natural product that derive from genetically encoded precursor peptides. However, RiPP gene clusters are particularly refractory to reliable bioinformatic predictions due to the absence of a common biosynthetic feature across all pathways. Here, we describe RiPPER, a new tool for the family-independent identification of RiPP precursor peptides and apply this methodology to search for novel thioamidated RiPPs in Actinobacteria. Until now, thioamidation was believed to be a rare post-translational modification, which is catalyzed by a pair of proteins (YcaO and TfuA) in Archaea. In Actinobacteria, the thioviridamide-like molecules are a family of cytotoxic RiPPs that feature multiple thioamides, and it has been proposed that a YcaO-TfuA pair of proteins also catalyzes their formation. Potential biosynthetic gene clusters encoding YcaO and TfuA protein pairs are common in Actinobacteria but the chemical diversity generated by these pathways is almost completely unexplored. A RiPPER analysis reveals a highly diverse landscape of precursor peptides encoded in previously undescribed gene clusters that are predicted to make thioamidated RiPPs. To illustrate this strategy, we describe the first rational discovery of a new family of thioamidated natural products, the thiovarsolins from Streptomyces varsoviensis.

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