scholarly journals Microfluidic automated plasmid library enrichment for biosynthetic gene cluster discovery

2020 ◽  
Vol 48 (8) ◽  
pp. e48-e48 ◽  
Author(s):  
Peng Xu ◽  
Cyrus Modavi ◽  
Benjamin Demaree ◽  
Frederick Twigg ◽  
Benjamin Liang ◽  
...  

Abstract Microbial biosynthetic gene clusters are a valuable source of bioactive molecules. However, because they typically represent a small fraction of genomic material in most metagenomic samples, it remains challenging to deeply sequence them. We present an approach to isolate and sequence gene clusters in metagenomic samples using microfluidic automated plasmid library enrichment. Our approach provides deep coverage of the target gene cluster, facilitating reassembly. We demonstrate the approach by isolating and sequencing type I polyketide synthase gene clusters from an Antarctic soil metagenome. Our method promotes the discovery of functional-related genes and biosynthetic pathways.

2021 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Sho Nishimura ◽  
Kazune Nakamura ◽  
Miyako Yamamoto ◽  
Daichi Morita ◽  
Teruo Kuroda ◽  
...  

Information on microbial genome sequences is a powerful resource for accessing natural products with significant activities. We herein report the unveiling of lucensomycin production by Streptomyces achromogenes subsp. streptozoticus NBRC14001 based on the genome sequence of the strain. The genome sequence of strain NBRC14001 revealed the presence of a type I polyketide synthase gene cluster with similarities to a biosynthetic gene cluster for natamycin, which is a polyene macrolide antibiotic that exhibits antifungal activity. Therefore, we investigated whether strain NBRC14001 produces antifungal compound(s) and revealed that an extract from the strain inhibited the growth of Candida albicans. A HPLC analysis of a purified compound exhibiting antifungal activity against C. albicans showed that the compound differed from natamycin. Based on HR-ESI-MS spectrometry and a PubChem database search, the compound was predicted to be lucensomycin, which is a tetraene macrolide antibiotic, and this prediction was supported by the results of a MS/MS analysis. Furthermore, the type I polyketide synthase gene cluster in strain NBRC14001 corresponded well to lucesomycin biosynthetic gene cluster (lcm) in S. cyanogenus, which was very recently reported. Therefore, we concluded that the antifungal compound produced by strain NBRC14001 is lucensomycin.


Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1447
Author(s):  
Hisayuki Komaki ◽  
Natsuko Ichikawa ◽  
Akira Hosoyama ◽  
Moriyuki Hamada ◽  
Yasuhiro Igarashi

Micromonospora sp. TP-A0316 and Micromonospora sp. TP-A0468 are producers of arisostatin and kosinostatin, respectively. Micromonospora sp. TP-A0316 showed a 16S rRNA gene sequence similarity of 100% to Micromonosporaoryzae CP2R9-1T whereas Micromonospora sp. TP-A0468 showed a 99.3% similarity to Micromonospora haikouensis 232617T. A phylogenetic analysis based on gyrB sequences suggested that Micromonospora sp. TP-A0316 is closely related to Micromonospora oryzae whereas Micromonospora TP-A0468 is an independent genomospecies. As Micromonospora sp. TP-A0468 showed some phenotypic differences to its closely related species, it was classified as a novel species, for which the name Micromonospora okii sp. nov. is proposed. The type strain is TP-A0468T (= NBRC 110461T). Micromonospora sp. TP-A0316 and M. okii TP-A0468T were both found to harbor 15 gene clusters for secondary metabolites such as polyketides and nonribosomal peptides in their genomes. Arisostatin-biosynthetic gene cluster (BGC) of Micromonospora sp. TP-A0316 closely resembled tetrocarcin A-BGC of Micromonospora chalcea NRRL 11289. A large type-I polyketide synthase gene cluster was present in each genome of Micromonospora sp. TP-A0316 and M. okii TP-A0468T. It was an ortholog of quinolidomicin-BGC of M. chalcea AK-AN57 and widely distributed in the genus Micromonospora.


2021 ◽  
Vol 19 (5) ◽  
pp. 1-11
Author(s):  
Amelia Cahya Anggelina ◽  
◽  
Delianis Pringgenies ◽  
Wilis Ari Setyati ◽  
◽  
...  

Actinomycetes are a group of bacteria that are widely distributed in soil, litter, water, and other natural sources. These Gram positive bacteria can produce hundreds of bioactive compounds, especially antibiotics. This research isolated culturable actinomycetes from mangrove sediments in the Semarang and Karimunjawa Island areas. The isolates that produce potential antibacterial compounds were identified by qualitative screening using the Biosynthetic Gene Cluster (NRPS/PKS) prediction approach. This research was conducted from June to November 2020. A total of 19 actinomycetes from Semarang and 17 actinomycetes from Karimunjawa were found to have at least one type of Biosynthetic Gene Cluster (NRPS, Type I or Type II PKS), but only three isolates had antibacterial activity against S. aureus, E. coli, and L. monocytogenes. Molecular identification found that the bacteria were similar to Brachybacterium paraconglomeratum (99.92%), Streptomyces pluripotens (100%), and Micromonospora chersina (99.08%). Results of the study concluded that the three bacterial isolates that had bacterial activity have similar genes with known antibiotic-producing genes and can potentially provide new antibiotic candidates.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 758
Author(s):  
Xiaohe Jin ◽  
Yunlong Zhang ◽  
Ran Zhang ◽  
Kathy-Uyen Nguyen ◽  
Jonathan S. Lindsey ◽  
...  

Tolyporphins A–R are unusual tetrapyrrole macrocycles produced by the non-axenic filamentous cyanobacterium HT-58-2. A putative biosynthetic gene cluster for biosynthesis of tolyporphins (here termed BGC-1) was previously identified in the genome of HT-58-2. Here, homology searching of BGC-1 in HT-58-2 led to identification of similar BGCs in seven other filamentous cyanobacteria, including strains Nostoc sp. 106C, Nostoc sp. RF31YmG, Nostoc sp. FACHB-892, Brasilonema octagenarum UFV-OR1, Brasilonema octagenarum UFV-E1, Brasilonema sennae CENA114 and Oculatella sp. LEGE 06141, suggesting their potential for tolyporphins production. A similar gene cluster (BGC-2) also was identified unexpectedly in HT-58-2. Tolyporphins BGCs were not identified in unicellular cyanobacteria. Phylogenetic analysis based on 16S rRNA and a common component of the BGCs, TolD, points to a close evolutionary history between each strain and their respective tolyporphins BGC. Though identified with putative tolyporphins BGCs, examination of pigments extracted from three cyanobacteria has not revealed the presence of tolyporphins. Overall, the identification of BGCs and potential producers of tolyporphins presents a collection of candidate cyanobacteria for genetic and biochemical analysis pertaining to these unusual tetrapyrrole macrocycles.


2007 ◽  
Vol 6 (7) ◽  
pp. 1210-1218 ◽  
Author(s):  
Daren W. Brown ◽  
Robert A. E. Butchko ◽  
Mark Busman ◽  
Robert H. Proctor

ABSTRACT Fumonisins are mycotoxins produced by some Fusarium species and can contaminate maize or maize products. Ingestion of fumonisins is associated with diseases, including cancer and neural tube defects, in humans and animals. In fungi, genes involved in the synthesis of mycotoxins and other secondary metabolites are often located adjacent to each other in gene clusters. Such genes can encode structural enzymes, regulatory proteins, and/or proteins that provide self-protection. The fumonisin biosynthetic gene cluster includes 16 genes, none of which appear to play a role in regulation. In this study, we identified a previously undescribed gene (FUM21) located adjacent to the fumonisin polyketide synthase gene, FUM1. The presence of a Zn(II)2Cys6 DNA-binding domain in the predicted protein suggested that FUM21 was involved in transcriptional regulation. FUM21 deletion (Δfum21) mutants produce little to no fumonisin in cracked maize cultures but some FUM1 and FUM8 transcripts in a liquid GYAM medium. Complementation of a Δfum21 mutant with a wild-type copy of the gene restored fumonisin production. Analysis of FUM21 cDNAs identified four alternative splice forms (ASFs), and microarray analysis indicated the ASFs were differentially expressed. Based on these data, we present a model for how FUM21 ASFs may regulate fumonisin biosynthesis.


BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Hye-Seon Kim ◽  
Jessica M. Lohmar ◽  
Mark Busman ◽  
Daren W. Brown ◽  
Todd A. Naumann ◽  
...  

Abstract Background Sphingolipids are structural components and signaling molecules in eukaryotic membranes, and many organisms produce compounds that inhibit sphingolipid metabolism. Some of the inhibitors are structurally similar to the sphingolipid biosynthetic intermediate sphinganine and are referred to as sphinganine-analog metabolites (SAMs). The mycotoxins fumonisins, which are frequent contaminants in maize, are one family of SAMs. Due to food and feed safety concerns, fumonisin biosynthesis has been investigated extensively, including characterization of the fumonisin biosynthetic gene cluster in the agriculturally important fungi Aspergillus and Fusarium. Production of several other SAMs has also been reported in fungi, but there is almost no information on their biosynthesis. There is also little information on how widely SAM production occurs in fungi or on the extent of structural variation of fungal SAMs. Results Using fumonisin biosynthesis as a model, we predicted that SAM biosynthetic gene clusters in fungi should include a polyketide synthase (PKS), an aminotransferase and a dehydrogenase gene. Surveys of genome sequences identified five putative clusters with this three-gene combination in 92 of 186 Fusarium species examined. Collectively, the putative SAM clusters were distributed widely but discontinuously among the species. We propose that the SAM5 cluster confers production of a previously reported Fusarium SAM, 2-amino-14,16-dimethyloctadecan-3-ol (AOD), based on the occurrence of AOD production only in species with the cluster and on deletion analysis of the SAM5 cluster PKS gene. We also identified SAM clusters in 24 species of other fungal genera, and propose that one of the clusters confers production of sphingofungin, a previously reported Aspergillus SAM. Conclusion Our results provide a genomics approach to identify novel SAM biosynthetic gene clusters in fungi, which should in turn contribute to identification of novel SAMs with applications in medicine and other fields. Information about novel SAMs could also provide insights into the role of SAMs in the ecology of fungi. Such insights have potential to contribute to strategies to reduce fumonisin contamination in crops and to control crop diseases caused by SAM-producing fungi.


2004 ◽  
Vol 70 (11) ◽  
pp. 6353-6362 ◽  
Author(s):  
Michelle C. Moffitt ◽  
Brett A. Neilan

ABSTRACT Nodularia spumigena is a bloom-forming cyanobacterium which produces the hepatotoxin nodularin. The complete gene cluster encoding the enzymatic machinery required for the biosynthesis of nodularin in N. spumigena strain NSOR10 was sequenced and characterized. The 48-kb gene cluster consists of nine open reading frames (ORFs), ndaA to ndaI, which are transcribed from a bidirectional regulatory promoter region and encode nonribosomal peptide synthetase modules, polyketide synthase modules, and tailoring enzymes. The ORFs flanking the nda gene cluster in the genome of N. spumigena strain NSOR10 were identified, and one of them was found to encode a protein with homology to previously characterized transposases. Putative transposases are also associated with the structurally related microcystin synthetase (mcy) gene clusters derived from three cyanobacterial strains, indicating a possible mechanism for the distribution of these biosynthetic gene clusters between various cyanobacterial genera. We propose an alternative hypothesis for hepatotoxin evolution in cyanobacteria based on the results of comparative and phylogenetic analyses of the nda and mcy gene clusters. These analyses suggested that nodularin synthetase evolved from a microcystin synthetase progenitor. The identification of the nodularin biosynthetic gene cluster and evolution of hepatotoxicity in cyanobacteria reported in this study may be valuable for future studies on toxic cyanobacterial bloom formation. In addition, an appreciation of the natural evolution of nonribosomal biosynthetic pathways will be vital for future combinatorial engineering and rational design of novel metabolites and pharmaceuticals.


2007 ◽  
Vol 52 (2) ◽  
pp. 574-585 ◽  
Author(s):  
Xiujun Zhang ◽  
Lawrence B. Alemany ◽  
Hans-Peter Fiedler ◽  
Michael Goodfellow ◽  
Ronald J. Parry

ABSTRACT The antibiotics lactonamycin and lactonamycin Z provide attractive leads for antibacterial drug development. Both antibiotics contain a novel aglycone core called lactonamycinone. To gain insight into lactonamycinone biosynthesis, cloning and precursor incorporation experiments were undertaken. The lactonamycin gene cluster was initially cloned from Streptomyces rishiriensis. Sequencing of ca. 61 kb of S. rishiriensis DNA revealed the presence of 57 open reading frames. These included genes coding for the biosynthesis of l-rhodinose, the sugar found in lactonamycin, and genes similar to those in the tetracenomycin biosynthetic gene cluster. Since lactonamycin production by S. rishiriensis could not be sustained, additional proof for the identity of the S. rishiriensis cluster was obtained by cloning the lactonamycin Z gene cluster from Streptomyces sanglieri. Partial sequencing of the S. sanglieri cluster revealed 15 genes that exhibited a very high degree of similarity to genes within the lactonamycin cluster, as well as an identical organization. Double-crossover disruption of one gene in the S. sanglieri cluster abolished lactonamycin Z production, and production was restored by complementation. These results confirm the identity of the genetic locus cloned from S. sanglieri and indicate that the highly similar locus in S. rishiriensis encodes lactonamycin biosynthetic genes. Precursor incorporation experiments with S. sanglieri revealed that lactonamycinone is biosynthesized in an unusual manner whereby glycine or a glycine derivative serves as a starter unit that is extended by nine acetate units. Analysis of the gene clusters and of the precursor incorporation data suggested a hypothetical scheme for lactonamycinone biosynthesis.


2009 ◽  
Vol 76 (1) ◽  
pp. 283-293 ◽  
Author(s):  
Hanne Jørgensen ◽  
Kristin F. Degnes ◽  
Alexander Dikiy ◽  
Espen Fjærvik ◽  
Geir Klinkenberg ◽  
...  

ABSTRACT A new compound, designated ML-449, structurally similar to the known 20-membered macrolactam BE-14106, was isolated from a marine sediment-derived Streptomyces sp. Cloning and sequencing of the 83-kb ML-449 biosynthetic gene cluster revealed its high level of similarity to the BE-14106 gene cluster. Comparison of the respective biosynthetic pathways indicated that the difference in the compounds' structures stems from the incorporation of one extra acetate unit during the synthesis of the acyl side chain. A phylogenetic analysis of the β-ketosynthase (KS) domains from polyketide synthases involved in the biosynthesis of macrolactams pointed to a common ancestry for the two clusters. Furthermore, the analysis demonstrated the formation of a macrolactam-specific subclade for the majority of the KS domains from several macrolactam-biosynthetic gene clusters, indicating a closer relationship between macrolactam clusters than with the macrolactone clusters included in the analysis. Some KS domains from the ML-449, BE-14106, and salinilactam gene clusters did, however, show a closer relationship with KS domains from the polyene macrolide clusters, suggesting potential acquisition rather than duplication of certain PKS genes. Comparison of the ML-449, BE-14106, vicenistatin, and salinilactam biosynthetic gene clusters indicated an evolutionary relationship between them and provided new insights into the processes governing the evolution of small-ring macrolactam biosynthesis.


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