scholarly journals Isolation and Identification of Actinomycetes Strains from Switzerland and their Biotechnological Potential

2020 ◽  
Vol 74 (5) ◽  
pp. 382-390 ◽  
Author(s):  
Fabienne Arn ◽  
David Frasson ◽  
Ivana Kroslakova ◽  
Fabio Rezzonico ◽  
Joël F. Pothier ◽  
...  

Actinomycetes strains isolated from different habitats in Switzerland were investigated for production of antibacterial and antitumoral compounds. Based on partial 16S rRNA gene sequences, the isolated strains were identified to genus level. Streptomyces as the largest genus of Actinobacteriawas isolated the most frequently. A screening assay using the OmniLog instrument was established to facilitate the detection of active compounds from actinomycetes. Extracts prepared from the cultivated strains able to inhibit Staphylococcus aureusand Escherichia coliwere further analysed by HPLC and MALDI-TOF MS to identify the produced antibiotics. In this study, the bioactive compound echinomycin was identified from two isolated Streptomycesstrains. Natural compounds similar to TPU-0037-C, azalomycin F4a 2-ethylpentyl ester, a derivative of bafilomycin A1, milbemycin-α8 and dihydropicromycin were detected from different isolated Streptomyces strains. Milbemycin-α8 showed cytotoxic activity against HT-29 colon cancer cells. The rare actinomycete,Micromonospora sp. Stup16_C148 produced a compound that matches with the antibiotic bottromycin A2. The draft genome sequence from Actinokineospora strain B136.1 was determined using Illumina and nanopore-based technologies. The isolated strain was not able to produce antibacterial compounds under standard cultivation conditions. The antiSMASH bioinformatics analyses of the genome from strain B136.1 identified biosynthetic gene clusters with identity values between 4% to 90% to known gene clusters encoding antibiotics. The combinations of cultivation conditions, screening assays, analytical methods and genome mining are important tools to characterize strains of actinomycetes for the identification of their potential to produce natural compounds with antimicrobial activity.

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Fabian Horn ◽  
Jörg Linde ◽  
Derek J. Mattern ◽  
Grit Walther ◽  
Reinhard Guthke ◽  
...  

Here, we report the draft genome sequence of Aspergillus calidoustus (strain SF006504) . The functional annotation of A. calidoustus predicts a relatively large number of secondary metabolite gene clusters. The presented genome sequence builds the basis for further genome mining.


Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 458
Author(s):  
Hui-Min Gao ◽  
Peng-Fei Xie ◽  
Xiao-Ling Zhang ◽  
Qiao Yang

A new versatile actinobacterium designated as strain NJES-13 was isolated from the feces of the Antarctic emperor penguin. This new isolate was found to produce two active gephyromycin analogues and bioflocculanting exopolysaccharides (EPS) metabolites. Phylogenetic analysis based on pairwise comparison of 16S rRNA gene sequences showed that strain NJES-13 was closely related to Mobilicoccus pelagius Aji5-31T with a gene similarity of 95.9%, which was lower than the threshold value (98.65%) for novel species delineation. Additional phylogenomic calculations of the average nucleotide identity (ANI, 75.9–79.1%), average amino acid identity (AAI, 52.4–66.9%) and digital DNA–DNA hybridization (dDDH, 18.6–21.9%), along with the constructed phylogenomic tree based on the up-to-date bacterial core gene (UBCG) set from the bacterial genomes, unequivocally separated strain NJES-13 from its close relatives within the family Dermatophilaceae. Hence, it clearly indicated that strain NJES-13 represented a putative new actinobacterial species isolated from the gut microbiota of mammals inhabiting the Antarctic. The obtained complete genome of strain NJES-13 consisted of a circular 3.45 Mb chromosome with a DNA G+C content of 67.0 mol%. Furthering genome mining of strain NJES-13 showed the presence of five biosynthetic gene clusters (BGCs) including one type III PKS responsible for the biosynthesis of the core of gephyromycins, and a series of genes encoding for bacterial EPS biosynthesis. Thus, based on the combined phylogenetic and active metabolites characterization presented in this study, we confidently conclude that strain NJES-13 is a novel, fresh actinobacterial candidate to produce active gephyromycins and microbial bioflocculanting EPS, with potential pharmaceutical, environmental and biotechnological implications.


2021 ◽  
Author(s):  
James Tambong ◽  
Renlin Xu ◽  
Diane Cuppels ◽  
Julie T Chapados ◽  
suzanne Gerdis ◽  
...  

Pseudomonas syringae pv. tomato is the causal agent of bacterial speck disease of field and greenhouse tomato plants. Only one Canadian whole genome sequence of this economically important pathogen is publicly available in NCBI GenBank. Here, we report 33 whole genome sequences of Canadian strains of P. syringae pv. tomato isolated in Ontario, Canada, between 1992 and 2008. The genome sequences exhibited average nucleotide identity values of 98.64-98.72 % with P. syringae pv. tomato ICMP 2844PT and DC3000, validating the taxonomic standing of these Canadian strains. The genome sizes ranged from 6.20-6.39 Mbp with G+C content of 58.6% and comprised 5,889-6,166 protein-coding sequences (CDSs). The strains had pan- and core-genomes of 6808 and 4,993 gene clusters, respectively. Genome mining of the strains for virulence factors identified typical adherence genes, proteins related to antiphagocytosis, secretion system apparatuses and effectors. Also, partial or complete achromobactin biosynthetic cluster and iron transport genes were identified in all the Canadian strains but absent in P. syringae pv. tomato DC3000 or ICMP 2844 (pathotype). These new whole genome data of Canadian strains of P. syringae pv. tomato could be useful resources in understanding the evolution of this pathogen.


2021 ◽  
Author(s):  
Janira Prichula ◽  
Muriel Primon-Barros ◽  
Romeu Luz ◽  
Ícaro Castro ◽  
Thiago Paim ◽  
...  

Abstract New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococcal recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56 %), 10 terpenes (13.70 %), and two (2.74 %) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value, and potential probiotic application.


2021 ◽  
Author(s):  
Xiujun Sun ◽  
Xianxian Luo ◽  
Chuan He ◽  
Zhenzhen Huang ◽  
Junwei Zhao ◽  
...  

Abstract A novel protease-producing actinobacterium, designated strain NEAU-A11T, was isolated from soil collected from Aohan banner, Chifeng, Inner Mongolia Autonomous Region, China, and characterised using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-A11T was indicated to belong to the genus Actinoplanes and was most closely related to Actinoplanes rectilineatus JCM 3194T (98.9 %). Cell walls contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell sugars were arabinose, xylose and glucose. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and two phosphatidylinositol mannosides. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8). The major fatty acids were C18:0, C16:0, C18:1 ω9c, C17:0 and C15:0. Genome sequencing revealed a genome size of 10,742,096 bp, a G + C content of 70.5 % and 9,514 protein-coding genes (CDSs), including 102 genes coding for protease. Genome mining analysis using antiSMASH 5.0 led to the identification of 20 putative gene clusters responsible for the production of diverse secondary metabolites. Phylogenetic analysis using the 16S rRNA gene sequences showed that the strain formed a stable clade with A. rectilineatus JCM 3194T in the genus Actinoplanes. However, whole-genome average nucleotide identity (ANI) value and the levels of digital DNA-DNA (dDDH) hybridization between strain NEAU- A11T and A. rectilineatus JCM 3194T was 81.1 % and 24.6 % (22.2–27.0 %), respectively. The values were well below the criteria for species delineation of 70% for dDDH and 95–96% for ANI, suggesting that the isolate differed genetically from its closely related type strain. In addition, evidences from phenotypic, chemotaxonomic and genotypic studies indicate that strain NEAU-A11T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes aureus sp. nov. is proposed, with NEAU-A11T (= CCTCC AA 2019063T = JCM 33971T) as the type strain.


2019 ◽  
Vol 8 (28) ◽  
Author(s):  
Walaa E. Hussein ◽  
Lingzi Xiaoli ◽  
Ahmed E. Yousef

Enterococcus durans OSY-EGY was isolated recently from cheese. The strain produces potent antimicrobial agents. Here, we present the draft genome sequence of the strain, with a genome size of 3,230,625 bp and an average G+C content of 37.69%. Draft genome mining identified several biosynthetic gene clusters encoding multiple antimicrobial peptides.


2022 ◽  
Author(s):  
Magdalena Śwecimska ◽  
Patrycja Golinska ◽  
Michael Goodfellow

Abstract A genomic-based polyphasic study was undertaken to establish the taxonomic status and biotechnological and ecological potential of a Streptomyces strain, isolate SF28T, that was recovered from the litter layer in a polish Pinus sylvestris forest. The isolate had morphological characteristics and chemotaxonomic properties consistent with its classification in the genus Streptomyces. It formed long straight chains of spores with smooth surfaces, contained LL-diaminopimelic acid and glucose and ribose in whole-organism hydrolysates, produced major proportions of straight, iso- and anteiso- fatty acids, hexa- and octa-hydrogenated menaquinones with nine isoprenoid units and had a polar lipid pattern composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, glycophospholipids and three uncharacterized components. Phylogenetic trees prepared using 16S rRNA gene and multilocus gene sequences of conserved housekeeping genes showed that the isolate formed a branch that was loosely associated with the type strains of several validly published Streptomyces species. A draft genome generated for the isolate was rich in natural product-biosynthetic gene clusters with the potential to produce new specialised metabolites, notably antibiotics, and stress related genes which provide an insight into how they may have adapted to the harsh conditions that prevail in acidic forest soils. A phylogenomic tree based on the genomes of the isolate and its phylogenetic neighbours confirmed that it formed a distinct lineage well separated from its closest evolutionary relatives. The isolate shared low average nucleotide index and digital DNA:DNA hybridization values with its phylogenomic neighbours and was also distinguished from them using a combination of cultural and micromorphological properties. Given this wealth of taxonomic data it is proposed that isolate SF28T (=DSM 113360T=PCM 3163T) be classified in the genus Streptomyces as Streptomyces pinistramenti sp. nov. The isolate showed pronounced antimicrobial activity, especially against fungal plant pathogens.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 588
Author(s):  
Kunjukrishnan Kamalakshi Sivakala ◽  
Karina Gutiérrez-García ◽  
Polpass Arul Jose ◽  
Thangadurai Thinesh ◽  
Rangasamy Anandham ◽  
...  

Searching for new bioactive metabolites from the bacterial genus Streptomyces is a challenging task. Combined genomic tools and metabolomic screening of Streptomyces spp. native to extreme environments could be a promising strategy to discover novel compounds. While Streptomyces of desertic origin have been proposed as a source of new metabolites, their genome mining, phylogenetic analysis, and metabolite profiles to date are scarcely documented. Here, we hypothesized that Streptomyces species of desert environments have evolved with unique biosynthetic potential. To test this, along with an extensive characterization of biosynthetic potential of a desert isolate Streptomyces sp. SAJ15, we profiled phylogenetic relationships among the closest and previously reported Streptomyces of desert origin. Results revealed that Streptomyces strains of desert origin are closer to each other and relatively distinct from Streptomyces of other environments. The draft genome of strain SAJ15 was 8.2 Mb in size, which had 6972 predicted genes including 3097 genes encoding hypothetical proteins. Successive genome mining and phylogenetic analysis revealed the presence of putative novel biosynthetic gene clusters (BGCs) with low incidence in another Streptomyces. In addition, high-resolution metabolite profiling indicated the production of arylpolyene, terpenoid, and macrolide compounds in an optimized medium by strain SAJ15. The relative abundance of different BGCs in arid Streptomyces differed from the non-arid counterparts. Collectively, the results suggested a distinct evolution of desert Streptomyces with a unique biosynthetic potential.


Author(s):  
Geeta Chhetri ◽  
Taegun Seo

A red-pigmented, aerobic, motile by gliding, pleomorphic to long-rods and divided by budding bacterium, Gram-stain negative bacterium, designated JH31T, was isolated from stream water of Jeongbang Waterfall, famous feature of Jeju Island, Republic of Korea. The cells grew at 9–40 °C (optimum, 28–30 °C), at pH 5.0–10.0 (pH 6.5–7.5) and with 0–6% NaCl (0% NaCl). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain JH31T forms a lineage within the family Hymenobacteriaceae and clusters with its closest related species Pontibacter virorsus KCTC 42941T (98.1%), Pontibacter salisaro KACC 16885T (98.0%), Pontibacter amylolyticus JCM 19653T (97.2%), Pontibacter ramchanderi KACC 17384T (97.2%) and Pontibacter lucknowensis DM9T (96.4%). Strain JH31T produced carotenoid-type pigments but no flexirubin-type pigments. The genome was 4117105 bp long with 18 contigs and 3509 protein-coding genes. The DNA G+C content was 49.7 mol%. The digital DNA–DNA hybridization and average nucleotide identity values between the genome sequence of strain JH31T and its closely related reference strains were less than 19 and 72%, respectively. The draft genome of strain JH31T contained vital gene clusters involved in resistance against various metals, antibiotics, toxic compounds and radiation. The respiratory quinone of strain JH31T was menaquinone 7 and the predominant cellular fatty acids were iso-C15:0, and summed feature 4 (comprising iso-C17:1 I and/or anteiso B). The major polar lipids were phosphatidylethanolamine, three unidentified glycolipids, one unidentified phospholipid, one unidentified phosphoglycolipid and one unidentified aminoglycolipid. The phylogenetic, physiochemical and biochemical data showed that strain JH31T should represent a novel species in the genus Pontibacter , for which the name Pontibacter aquaedesilientis sp. nov. is proposed. The type strain for this novel species is JH31T (KACC 21705T=NBRC 114480T).


2021 ◽  
Author(s):  
Rima Ouchene ◽  
Didier Stien ◽  
Juliette Segret ◽  
Mouloud Kecha ◽  
Alice MS Rodrigues ◽  
...  

Multi-omic approaches have recently made big strides towards the effective exploration of microorganisms and accelerating the discovery of new bioactive compounds. We combined metabolomic, molecular networking, and genomic-based approaches to investigate the metabolic potential of the Streptomyces sp. RO-S4 strain isolated from the polluted waters of Bejaia Bay in Algeria. Antagonistic assays against methicillin-resistant Staphylococcus aureus with RO-S4 organic extracts showed an inhibition zone of 20 mm by the agar diffusion method, and its minimum inhibitory concentration was 16 μg/mL. A molecular network was created using GNPS and annotated through the comparison of MS/MS spectra against several databases. The predominant compounds in the RO-S4 extract belonged to the angucyclines family. Three compounds were annotated as known metabolites, while all the others were putatively new to Science. Notably, all compounds had fridamycin-like aglycones, and several of them had a lactonized D ring analogous to that of urdamycin L. The whole genome of Streptomyces RO-S4 was sequenced to identify the biosynthetic gene cluster (BGC) encoding for these angucyclines, which yielded a draft genome of 7,497,846 bp with 72.4% G+C content. Subsequently, a genome mining analysis revealed 19 putative biosynthetic gene clusters, including a grincamycin-like BGC with a high similarity to that of Streptomyces sp. CZN-748 previously reported to also produce mostly open fridamycin-like aglycones. As the ring-opening process leading to these compounds is still not defined, we performed comparative analysis with other angucycline BGCs and advanced some hypotheses to explain the ring-opening and lactone formation, possibly linked to the uncoupling between the activity of GcnE and GcnM homologues in the RO-S4 strain. The combination of metabolomic and genomic approaches greatly improved the interpretation of the metabolic potential of the RO-S4 strain.


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