scholarly journals Classification and characterization of endophytic actinomycetes isolated from cinnamomum cassia presl

2018 ◽  
Vol 16 (1) ◽  
pp. 149-155
Author(s):  
Vu Thi Hanh Nguyen ◽  
Chu Ky Son ◽  
Phi Quyet Tien

Currently, antibiotic resistance in pathogenic bacteria is a significant clinical problem with the increase of deseases and a serious public health concern. Thus, the identification of new antimicrobial agents, especially the secondary metabolites products by endophytic actinobacteria from medical plants could be promising sources of biologically active compounds in medical fields. This study focused on identification and evaluation of antimicrobial activity against pathogens; genes involved in their secondary metabolisms, and screening of anthracycline producing capacity (mainly presented in anti-cancer antibiotics) of YBQ75 isolated from Cinnamomum cassia Presl. plants in Yen Bai province. Based on manual of bacterial classification, method in International Streptomyces Project (ISP) and the 16S rRNA gene sequence (GenBank Acc. No. KR814822), the endophytic actinomycetes YBQ75 was named Streptomyces cavourensis YBQ75 with 100% identity. The strain S. cavourensis YBQ75 showed the remarkable antibacterial activities against 5 tested pathogens (Salmonella enterica ATCC 14028 (22.0 mm); Pseudomonas aeruginosa CNLM (19.3 mm); Staphylococcus epidermidis ATCC 12228 (19.3 mm); Enterobacter aerogenes ATCC 13048 (17.7 mm) and Proteus vulgaris CNLM (16.3 mm)) in the total of 9 tested pathogens. The detection of genes involved in antibiotic synthesis indicated that the strain S. cavourensis YBQ75 consists of all three genes related to antibiotic synthesis including polyketide synthase (pks-I) type I, polyketide synthase type II (pks-II) and nonribosomal peptide synthetase (nrps). Premarilly result showed that the strain S. cavourensis YBQ75 also present as an anthracycline productive actinomycetes. The resutls demonstrated that the endophytic actinomycetes S. cavourensis YBQ75 from medical plants could be promising sources for the production of antibiotics and anthracycline anticancer compounds.

2010 ◽  
Vol 76 (13) ◽  
pp. 4377-4386 ◽  
Author(s):  
Jeffrey E. Janso ◽  
Guy T. Carter

ABSTRACT The culturable diversity of endophytic actinomycetes associated with tropical, native plants is essentially unexplored. In this study, 123 endophytic actinomycetes were isolated from tropical plants collected from several locations in Papua New Guinea and Mborokua Island, Solomon Islands. Isolates were found to be prevalent in roots but uncommon in leaves. Initially, isolates were dereplicated to the strain level by ribotyping. Subsequent characterization of 105 unique strains by 16S rRNA gene sequence analysis revealed that 17 different genera were represented, and rare genera, such as Sphaerisporangium and Planotetraspora, which have never been previously reported to be endophytic, were quite prevalent. Phylogenetic analyses grouped many of the strains into clades distinct from known genera within Thermomonosporaceae and Micromonosporaceae, indicating that they may be unique genera. Bioactivity testing and liquid chromatography-mass spectrometry (LC-MS) profiling of crude fermentation extracts were performed on 91 strains. About 60% of the extracts exhibited bioactivity or displayed LC-MS profiles with spectra indicative of secondary metabolites. The biosynthetic potential of 29 nonproductive strains was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. Despite their lack of detectable secondary metabolite production in fermentation, most were positive for type I (66%) and type II (79%) PKS genes, and all were positive for NRPS genes. These results suggest that tropical plants from New Guinea and the adjacent archipelago are hosts to unique endophytic actinomycetes that possess significant biosynthetic potential.


Author(s):  
Alimuddin Ali ◽  
Herlina Rante

Objective: The objective of this research was to isolate and characterize endophytic bacteria from Talinum triangulare having antifungal activity.Methods: The endophytic bacteria were isolated from roots tissue of Talinum triangulare by surface sterilization method. The isolates were cultured in Trypticase Soybean agar and antagonist activities were evaluated by dual culture assay against Fusarium oxysporum, Trichoderma reesei and Candida albicans. For metabolite antifungal activities, bacterial isolates were grown for 4 d in TS broth at 35 °C under shaking condition. The antifungal activities of the supernatant extract were determined by using the disk agar diffusion. Polyketide synthase (PKS I) and NRPS genes fragments of all isolates were amplified.Results: The result reveals that 4 of 23 endophytic bacterial isolates demonstrated great antifungal potentiality against many tested fungi. Polyketide synthase (PKS I) and NRPS genes amplification were showed 10 and 4 of endophytic isolates detected harboring PKS type I and NRPS genes, respectively. In general, high frequencies of positive PCR amplification were obtained for PKS I (43.47%). Phylogenetic analyses based on the 16S rRNA gene sequence, morphological, physiological and biochemical showed that the isolates were identified as a member of genus Bacillus and Brevibacillus.Conclusion: These results indicated that the endophytic bacteria from java ginseng could be used as an alternative source of antifungal agents.


Microbiology ◽  
2010 ◽  
Vol 156 (8) ◽  
pp. 2343-2353 ◽  
Author(s):  
Marco Gottelt ◽  
Stefan Kol ◽  
Juan Pablo Gomez-Escribano ◽  
Mervyn Bibb ◽  
Eriko Takano

Genome sequencing of Streptomyces coelicolor A3(2) revealed an uncharacterized type I polyketide synthase gene cluster (cpk). Here we describe the discovery of a novel antibacterial activity (abCPK) and a yellow-pigmented secondary metabolite (yCPK) after deleting a presumed pathway-specific regulatory gene (scbR2) that encodes a member of the γ-butyrolactone receptor family of proteins and which lies in the cpk gene cluster. Overproduction of yCPK and abCPK in a scbR2 deletion mutant, and the absence of the newly described compounds from cpk deletion mutants, suggest that they are products of the previously orphan cpk biosynthetic pathway in which abCPK is converted into the yellow pigment. Transcriptional analysis suggests that scbR2 may act in a negative feedback mechanism to eventually limit yCPK biosynthesis. The results described here represent a novel approach for the discovery of new, biologically active compounds.


2020 ◽  
Vol 17 (4) ◽  
pp. 757-766
Author(s):  
Nguyen Quang Huy ◽  
Vu Thi Hanh Nguyen ◽  
Nguyen Van The ◽  
Bui Thi Lien ◽  
Le Thi Thu Hang ◽  
...  

Vietnam is recognized as one of the countries with the high diversity of medicinal plant species in the world, nevertheless little is known about the distribution, diversity and biological activity of endophytic actinomycetes associated with host plants. The present study aimed to evaluate antimicrobial and cytotoxic activities of four endophytic Streptomyces strains including Streptomyces sp. HBQ75, HBQ87, HBQ102 and HBQ104 isolated from different organs (roots, stems or leaves) of Cinnamomum cassia Presl. Analysis of 16S rRNA gene sequences and the phylogenetic tree assigned them to four different Streptomyces species as follow Streptomyces fulvissimus HBQ75, Streptomyces parvulus HBQ87, Streptomyces pratensis HBQ102 and Streptomyces ribosidificus HBQ104. These strains exhibited broad antimicrobial spectrum against at least five out of nine pathogens tested, among them S. parvulus HBQ87 showed the best activity (inhibition zones >20 mm). Interestingly, S. parvulus HBQ87 carried all three genes (pks-I, pks-II and nrps) encoding for polyketide synthase or non-ribosomal peptide synthetase enzymes involved in biosynthesis of secondary metabolites, while the remaining strains only possessed one or two genes. All the Streptomyces strains were positive for the anthracyclines-like antibiotic activity. The cell-free supernatants of S. parvulus HBQ87 revealed remarkable inhibitory effects against all three human cacinomar cell lines including hepatoma Hep3B, breast adenocarcinoma MCF7 and lung cancer A549 cells at both concentrations tested (30 µg/mL and 100 µg/mL), while S. fulvissimus HBQ75 and S. pratensis HBQ102 were active against only Hep3B and MCF7 cells. In conclusion, the phenotypic and genotypic features of the four endophytic Streptomyces strains suggest that they have a capacity to produce different broad-spectrum secondary metabolites. Among them, S. parvulus HBQ87 could be the most potential candidate for the production of important antimicrobial and antitumor compounds.


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.


2020 ◽  
Vol 11 ◽  
Author(s):  
Alinne L. R. Santana-Pereira ◽  
Megan Sandoval-Powers ◽  
Scott Monsma ◽  
Jinglie Zhou ◽  
Scott R. Santos ◽  
...  

Soil microorganisms historically have been a rich resource for natural product discovery, yet the majority of these microbes remain uncultivated and their biosynthetic capacity is left underexplored. To identify the biosynthetic potential of soil microorganisms using a culture-independent approach, we constructed a large-insert metagenomic library in Escherichia coli from a topsoil sampled from the Cullars Rotation (Auburn, AL, United States), a long-term crop rotation experiment. Library clones were screened for biosynthetic gene clusters (BGCs) using either PCR or a NGS (next generation sequencing) multiplexed pooling strategy, coupled with bioinformatic analysis to identify contigs associated with each metagenomic clone. A total of 1,015 BGCs were detected from 19,200 clones, identifying 223 clones (1.2%) that carry a polyketide synthase (PKS) and/or a non-ribosomal peptide synthetase (NRPS) cluster, a dramatically improved hit rate compared to PCR screening that targeted type I polyketide ketosynthase (KS) domains. The NRPS and PKS clusters identified by NGS were distinct from known BGCs in the MIBiG database or those PKS clusters identified by PCR. Likewise, 16S rRNA gene sequences obtained by NGS of the library included many representatives that were not recovered by PCR, in concordance with the same bias observed in KS amplicon screening. This study provides novel resources for natural product discovery and circumvents amplification bias to allow annotation of a soil metagenomic library for a more complete picture of its functional and phylogenetic diversity.


2019 ◽  
Vol 14 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Junaid Khan ◽  
Amit Alexander ◽  
Mukta Agrawal ◽  
Ajazuddin ◽  
Sunil Kumar Dubey ◽  
...  

Diabetes and its complications are a significant health concern throughout the globe. There are physiological differences in the mechanism of type-I and type-II diabetes and the conventional drug therapy as well as insulin administration seem to be insufficient to address the problem at large successfully. Hypoglycemic swings, frequent dose adjustments and resistance to the drug are major problems associated with drug therapy. Cellular approaches through stem cell based therapeutic interventions offer a promising solution to the problem. The need for pancreatic transplants in case of Type- I diabetes can also be by-passed/reduced due to the formation of insulin producing β cells via stem cells. Embryonic Stem Cells (ESCs) and induced Pluripotent Stem Cells (iPSCs), successfully used for generating insulin producing β cells. Although many experiments have shown promising results with stem cells in vitro, their clinical testing still needs more exploration. The review attempts to bring into light the clinical studies favoring the transplantation of stem cells in diabetic patients with an objective of improving insulin secretion and improving degeneration of different tissues in response to diabetes. It also focuses on the problems associated with successful implementation of the technique and possible directions for future research.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Min-Ji Kim ◽  
Setu Bazie Tagele ◽  
HyungWoo Jo ◽  
Min-Chul Kim ◽  
YeonGyun Jung ◽  
...  

AbstractThe skin microbiome, especially the axillary microbiome, consists of odor-causing bacteria that decompose odorless sweat into malodor compounds, which contributes to the formation of body odor. Plant-derived products are a cheap source of bioactive compounds that are common ingredients in cosmetics. Microbial bioconversion of natural products is an ecofriendly and economical method for production of new or improved biologically active compounds. Therefore, in this study, we tested the potential of a Lactobacillus acidophilus KNU-02-mediated bioconverted product (BLC) of Lotus corniculatus seed to reduce axillary malodor and its effect on the associated axillary microbiota. A chemical profile analysis revealed that benzoic acid was the most abundant chemical compound in BLC, which increased following bioconversion. Moreover, BLC treatment was found to reduce the intensity of axillary malodor. We tested the axillary microbiome of 18 study participants, divided equally into BLC and placebo groups, and revealed through 16S rRNA gene sequencing that Staphylococcus, Corynebacterium, and Anaerococcus were the dominant taxa, and some of these taxa were significantly associated with axillary malodor. After one week of BLC treatment, the abundance of Corynebacterium and Anaerococcus, which are associated with well-known odor-related genes that produce volatile fatty acids, had significantly reduced. Likewise, the identified odor-related genes decreased after the application of BLC. BLC treatment enhanced the richness and network density of the axillary microbial community. The placebo group, on the other hand, showed no difference in the microbial richness, odor associated taxa, and predicted functional genes after a week. The results demonstrated that BLC has the potential to reduce the axillary malodor and the associated odor-causing bacteria, which makes BLC a viable deodorant material in cosmetic products.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Rong Xu ◽  
Renfei Lu ◽  
Tao Zhang ◽  
Qunfu Wu ◽  
Weihua Cai ◽  
...  

AbstractSARS-CoV-2 is the cause of COVID-19. It infects multiple organs including the respiratory tract and gut. Dynamic changes of regional microbiomes in infected adults are largely unknown. Here, we performed longitudinal analyses of throat and anal swabs from 35 COVID-19 and 19 healthy adult controls, as well as 10 non-COVID-19 patients with other diseases, by 16 S rRNA gene sequencing. The results showed a partitioning of the patients into 3-4 categories based on microbial community types (I-IV) in both sites. The bacterial diversity was lower in COVID-19 patients than healthy controls and decreased gradually from community type I to III/IV. Although the dynamic change of microbiome was complex during COVID-19, a synchronous restoration of both the upper respiratory and gut microbiomes from early dysbiosis towards late more diverse status was observed in 6/8 mild COVID-19 adult patients. These findings reveal previously unknown interactions between upper respiratory and gut microbiomes during COVID-19.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhi Zong ◽  
Yujun Wei ◽  
Jiang Ren ◽  
Long Zhang ◽  
Fangfang Zhou

AbstractThe outbreak of the novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a serious public health concern. Patients with cancer have been disproportionately affected by this pandemic. Increasing evidence has documented that patients with malignancies are highly susceptible to severe infections and mortality from COVID-19. Recent studies have also elucidated the molecular relationship between the two diseases, which may not only help optimize cancer care during the pandemic but also expand the treatment for COVID-19. In this review, we highlight the clinical and molecular similarities between cancer and COVID-19 and summarize the four major signaling pathways at the intersection of COVID-19 and cancer, namely, cytokine, type I interferon (IFN-I), androgen receptor (AR), and immune checkpoint signaling. In addition, we discuss the advantages and disadvantages of repurposing anticancer treatment for the treatment of COVID-19.


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