scholarly journals Bioactive compounds derived from Streptomyces sp. SA32: antibacterial activity, chemical profile, and their related genes

2021 ◽  
Vol 948 (1) ◽  
pp. 012062
Author(s):  
D Ryandini ◽  
O K Radjasa ◽  
Oedjijono

Abstract Microbes which are resistant to drugs and antibiotics as well as multi-drug resistant (MDR) microbes have developed due to the improper use of antibiotics and led to explore the microbial isolates as the sources of new antibiotics or those with highly effective and stabile attack. Streptomyces sp. SA32 was selected to inhibit the growth of MDR bacteria Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, Enterobacter cloaceae, and Enterococcus sp. E. coli was sensitive to crude extracts of Streptomyces sp. SA32 at the concentration of 19 g.mL-1 with moderate strength against E. cloacae. The bioactive compounds analyzed using thin layer chromatography and phytochemical methods showed that the spot with Rf 0.63 and 0.68 was polyketide compound and that with Rf 0.74 was flavonoid compound. The bioautography assay on the TLC plate confirmed the absence of MDR bacterial growth on polyketide and flavonoid spots. The synthesis of antibacterial compounds was also confirmed by the successful analysis on both non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) gene sequences.

2011 ◽  
Vol 7 ◽  
pp. 1622-1635 ◽  
Author(s):  
Jan-Christoph Kehr ◽  
Douglas Gatte Picchi ◽  
Elke Dittmann

Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.


2020 ◽  
Vol 4 (1) ◽  
pp. 1-14
Author(s):  
Carine M.N. Ngaffo ◽  
Simplice B. Tankeo ◽  
Michel-Gael F. Guefack ◽  
Brice E. N. Wamba ◽  
Paul Nayim ◽  
...  

Abstract Background: Bacterial infections involving the multidrug resistant (MDR) strains are among the top leading causes of death throughout the world. Healthcare system across the globe has been suffering from an extra-ordinary burden in terms of looking for the new and more potent antimicrobial compounds. The aim of the present study was to determine the antibacterial activity of some Cameroonian edible plants (Garcinia lucida bark, Phoenix dactylifera pericarps, Theobroma cacao pod, Solanum macrocarpon leaves and Termitomyces titanicus whole plant) and their antibiotics-potentiation effects against some MDR Gram-negative bacteria phenotypes expressing efflux pumps (Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa and Providencia stuartii strains). Methods: The antibacterial activities of plant extract alone and in combination with usual antibiotics were carried out using the micro-dilution method. The effects of the most active plant extract (Garcinia lucida bark) on H+-ATPase-mediated proton pumps and on bacterial growth kinetic were performed using experimental protocols, while qualitative reference methods were used to highligh the major groups of secondary metabolites present in the extracts. Results: Qualitative phytochemical screening of plant extracts indicated that all analysed secondary metabolites were present in Theobroma cacao and Termitomyces titanicus while one (saponins) of them was absent in Garcinia lucida and Solanum macrocarpon. Only three of them (polyphenols, flavonoids and saponins) were detected in Phoenix dactylifera. Antibacterial essays showed that G. lucida was the most active plant as it inhibited the growth of all studied bacteria with strong activity (MIC<100 µg/mL) against E. coli ATCC8739, significant activity (100≤MIC≤512 µg/mL) against 80% of bacteria and moderate activity (512<MIC≤2048 µg/mL) against E. coli AG100A and E. aerogenes (EA289 and CM64). It was followed by T. cacao and S. macrocarpon extracts which exhibited an antibacterial potential against 95% and 80% of bacterial strains, respectively. These three extracts exhibited a bactericidal effect on a few bacteria. Extracts from T. titanicus and P. dactylifera were less active as they moderately (512<MIC≤2048 µg/mL) inhibited the growth of 35% and 10% of bacteria. All extracts selectively potentiated the activities of all antibiotics with improvement activity factors (IAF) ranging from 2 to 256. G. lucida, T. cacao and S. macrocarpon potentiated the activities of 100%, 89% and 67% of antibiotics respectively against more than 70%, suggesting that they contain bioactive compounds which could be considered as efflux pumps inhibitors. Whereas T. titanicus and P. dactylifera improved the activities of almost 40% and 20% of antibiotics, respectively. This increase of activities also characterizes synergistic effects between antibiotics and these bioactive compounds. G. lucida extract at all tested concentrations, strongly inhibited the growth of bacterial strain E. coli ATCC8739 and exhibited an inhibitory effect on this bacterial H+-ATPase-mediated proton pumps increasing the pH of the medium. Conclusion: The overall results indicated that food plants among which G. lucida, T. cacao and S. macrocarpon could have a benefit interest in combatting resistant types of bacteria. Keywords: Food plants; infectious diseases; MDR bacteria; efflux pumps; antibiotics; secondary metabolites.


Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 304
Author(s):  
Simone Bacchiocchi ◽  
Debora Campacci ◽  
Melania Siracusa ◽  
Alessandra Dubbini ◽  
Francesca Leoni ◽  
...  

Tetrodotoxins (TTXs), potent neurotoxins, have become an increasing concern in Europe in recent decades, especially because of their presence in mollusks. The European Food Safety Authority published a Scientific Opinion setting a recommended threshold for TTX in mollusks of 44 µg equivalent kg−1 and calling all member states to contribute to an effort to gather data in order to produce a more exhaustive risk assessment. The objective of this work was to assess TTX levels in wild and farmed mussels (Mytilus galloprovincialis) harvested in 2018–2019 along the coastal area of the Marche region in the Central Adriatic Sea (Italy). The presence of Vibrio spp. carrying the non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes, which are suspected to be involved in TTX biosynthesis, was also investigated. Out of 158 mussel samples analyzed by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS), 11 (7%) contained the toxins at detectable levels (8–26 µg kg−1) and 3 (2%) contained levels above the EFSA safety threshold (61–76 µg kg−1). Contaminated mussels were all harvested from natural beds in spring or summer. Of the 2019 samples, 70% of them contained V. alginolyticus strains with the NRPS and/or PKS genes. None of the strains containing NRPS and/or PKS genes showed detectable levels of TTXs. TTXs in mussels are not yet a threat in the Marche region nor in Europe, but further investigations are surely needed.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1100
Author(s):  
Wioletta Parys ◽  
Małgorzata Dołowy ◽  
Alina Pyka-Pająk

The present study summarizes the new strategies including advanced equipment and validation parameters of liquid and gas chromatography methods i.e., thin-layer chromatography (TLC), column liquid chromatography (CLC), and gas chromatography (GC) suitable for the identification and quantitative determination of different natural and synthetic bioactive compounds present in food and food products, which play an important role in human health, within the period of 2019–2021 (January). Full characteristic of some of these procedures with their validation parameters is discussed in this work. The present review confirms the vital role of HPLC methodology in combination with different detection modes i.e., HPLC-UV, HPLC-DAD, HPLC-MS, and HPLC-MS/MS for the determination of natural and synthetic bioactive molecules for different purposes i.e., to characterize the chemical composition of food as well as in the multi-residue analysis of pesticides, NSAIDs, antibiotics, steroids, and others in food and food products.


2017 ◽  
Vol 5 (21) ◽  
Author(s):  
Scarlett Alonso-Carmona ◽  
Blanca Vera-Gargallo ◽  
Rafael R. de la Haba ◽  
Antonio Ventosa ◽  
Horacio Sandoval-Trujillo ◽  
...  

ABSTRACT The draft genome sequence of Saccharomonospora sp. strain LRS4.154, a moderately halophilic actinobacterium, has been determined. The genome has 4,860,108 bp, a G+C content of 71.0%, and 4,525 open reading frames (ORFs). The clusters of PKS and NRPS genes, responsible for the biosynthesis of a large number of biomolecules, were identified in the genome.


2021 ◽  
Vol 11 (9) ◽  
pp. 4315
Author(s):  
Emanuel Vamanu ◽  
Laura Dorina Dinu ◽  
Cristina Mihaela Luntraru ◽  
Alexandru Suciu

Bioactive compounds and phenolic compounds are viable alternatives to antibiotics in recurrent urinary tract infections. This study aimed to use a natural functional product, based on the bioactive compounds’ composition, to inhibit the uropathogenic strains of Escherichia coli. E. coli ATCC 25922 was used to characterize the IVCM (new in vitro catheterization model). As support for reducing bacterial proliferation, the cytotoxicity against a strain of Candida albicans was also determined (over 75% at 1 mg/mL). The results were correlated with the analysis of the distribution of biologically active compounds (trans-ferulic acid-268.44 ± 0.001 mg/100 g extract and an equal quantity of Trans-p-coumaric acid and rosmarinic acid). A pronounced inhibitory effect against the uropathogenic strain E. coli 317 (4 log copy no./mL after 72 h) was determined. The results showed a targeted response to the product for tested bacterial strains. The importance of research resulted from the easy and fast characterization of the functional product with antimicrobial effect against uropathogenic strains of E. coli. This study demonstrated that the proposed in vitro model was a valuable tool for assessing urinary tract infections with E. coli.


2015 ◽  
Vol 81 (16) ◽  
pp. 5290-5298 ◽  
Author(s):  
Mahmoud Kamal Ahmadi ◽  
Samar Fawaz ◽  
Charles H. Jones ◽  
Guojian Zhang ◽  
Blaine A. Pfeifer

ABSTRACTYersiniabactin (Ybt) is a mixed nonribosomal peptide-polyketide natural product natively produced by the pathogenYersinia pestis. The compound enables iron scavenging capabilities upon host infection and is biosynthesized by a nonribosomal peptide synthetase featuring a polyketide synthase module. This pathway has been engineered for expression and biosynthesis usingEscherichia colias a heterologous host. In the current work, the biosynthetic process for Ybt formation was improved through the incorporation of a dedicated step to eliminate the need for exogenous salicylate provision. When this improvement was made, the compound was tested in parallel applications that highlight the metal-chelating nature of the compound. In the first application, Ybt was assessed as a rust remover, demonstrating a capacity of ∼40% compared to a commercial removal agent and ∼20% relative to total removal capacity. The second application tested Ybt in removing copper from a variety of nonbiological and biological solution mixtures. Success across a variety of media indicates potential utility in diverse scenarios that include environmental and biomedical settings.


1970 ◽  
Vol 17 (2) ◽  
Author(s):  
Lindawati S. A. ◽  
Haniyah Y. S. ◽  
Miwada I N. S. ◽  
Inggriati N. W. T. ◽  
Hartawan M. ◽  
...  

Yogurt merupakan minuman susu yang difermentasi dengan menggunakan bakteri asam laktat Lactobacillus bulgaricus dan Streptococcus thermophyllus sebagai starter. Tujuan penelitian untuk mengetahui kemampuan tertinggi dari yogurt berbasis air kelapa dalam menghambat pertumbuhan bakteri pathogen (Salmonella, Staphylococcus, Klebsiela pneumonia dan E.coli) secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan empat perlakuan dan empat ulangan. Keempat perlakuan tersebut: Ko: susu skim 12%+air; K1: susu skim 12%+air kelapa gading; K2: susu skim 12%+kelapa gading bulan; K3: susu skim 12%+air kelapa hijau. Peubah yang diamati adalah aktivitas antimikroba yogurt terhadap bakteri pathogen (Salmonellatyphi, Staphylococcus, Klebsiella pneumonia dan E.coli), total plate count (TPC), total bakteri asam laktat dan E,coli. Hasil penelitian menunjukkan bahwa aktivitas antimikroba tertinggi diperoleh pada yogurt berbasis air kelapa bulan terhadap bakeri Salmonella typhi dan Staphylococcus masing-masing sebesar 0,21 dan 0,26 cm dengan total bakteri asam laktat1,1×107 cfu/mL sedangkan untuk Klebsiella pneumonia dan E.coli diperoleh pada yogurt berbasis air kelapa gading sebesar 0,38 dan 0,64 mm dengan total bakteri asam laktat 3,1×106 cfu/mL.Dari hasil penelitian dapat disimpulkan bahwa yogurt berbasis air kelapa gading, bulan, hijau dan tanpa air kelapa memiliki aktivitas antimikroba berspektrum luas (menghambat bakteri gram positif dan negatif).


2010 ◽  
Vol 59 (3) ◽  
pp. 207-212 ◽  
Author(s):  
M.I. ABOU-DOBARA ◽  
M.A. DEYAB ◽  
E.M. ELSAWY ◽  
H.H. MOHAMED

Thirty nine isolates of Escherichia coli, twenty two isolates of Klebsiella pneumoniae and sixteen isolates of Pseudomonas aeruginosa isolated from urinary tract infected patients were analyzed by antimicrobial susceptibility typing and random amplified polymorphic DNA (RAPD)-PCR. Antibiotic susceptibility testing was carried out by microdilution and E Test methods. From the antibiotic susceptibility, ten patterns were recorded (four for E. coli, three for K. pneumoniae and three for P. aeruginosa respectively). Furthermore, genotyping showed seventeen RAPD patterns (seven for E. coli, five for K. pneumoniae and five for P. aeruginosa respectively). In this study, differentiation of strains of E. coli, K. pneumoniae and P. aeruginosa from nosocomial infection was possible with the use of RAPD.


2021 ◽  
Vol 26 (1) ◽  
pp. 8-15
Author(s):  
Shiv Nandan Sah ◽  
Ramesh Majhi ◽  
Sunil Regmi ◽  
Arjun Ghimire ◽  
Bhageshwor Biswas ◽  
...  

Realizing an increasing need for a novel antibiotic, this study was carried out to screen antibacterial metabolites producing actinomycetes from 15 soil samples collected from Taplejung. Antibacterial metabolites producing actinomycetes were confirmed by primary screening and secondary screening. Macroscopic, microscopic, and biochemical characteristics were used for presumptive identification of probable actinomycetes genera. The potential isolate was cultured in starch casein broth for production of possible antibacterial compound. The antibacterial compound was extracted from fermented broth using organic solvents like ethyl acetate, n-butanol, chloroform, dichloromethane, and methanol. Among 24 isolates, only one (T18) showed antibacterial activity against both Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Salmonella Typhi and Pseudomonas aeruginosa) test-bacteria. The isolate was considered as Streptomyces spp based on microscopy and various biochemical, and physiological characteristics. Extracted antibacterial metabolite showed antibacterial activity with a MIC value of 1.2 mg/mL against E. coli (ATCC 25922). The chromatogram in Thin Layer Chromatography showed only one spot exhibited by extract with Rf value 0.87 suggested that the isolate produced a compound that was completely different from the spot with Rf value 0.94 produced by gentamicin (standard). This study revealed the distribution of the potent antibacterial metabolite producing actinomycetes in the soils of Taplejung.


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