Streptomyces Chrestomyceticus Research Articles

Acetaminophen-traces bioremediation with novel phenotypically and genotypically characterized 2 Streptomyces strains using chemo-informatics, in vivo, and in vitro experiments for cytotoxicity and biological activity

We isolated two novel bacterial strains, active against the environmental pollutant acetaminophen/Paracetamol®. Streptomyces chrestomyceticus (symbol RS2) and Flavofuscus (symbol M33) collected from El-Natrun Valley, Egypt—water, sediment, and sand samples, taxonomically characterized using a transmission electron microscope (TEM). Genotypic identification, based on 16S rRNA gene sequence analysis followed by BLAST alignment, were deposited on the NCBI as 2 novel strains https://www.ncbi.nlm.nih.gov/nuccore/OM665324 and https://www.ncbi.nlm.nih.gov/nuccore/OM665325. The phylogenetic tree was constructed. Acetaminophen secondary or intermediate product’s chemical structure was identified by GC/LC MS. Some selected acetaminophen secondary-product extracts and derived compounds were examined against a panel of test micro-organisms and fortunately showed a good anti-microbial effect. In silico chemo-informatics Swiss ADMET evaluation was used in the selected bio-degradation extracts for absorption (gastric), distribution (to CNS), metabolism (hepatic), excretion (renal), and finally not toxic, being non-mutagenic/teratogenic or genotoxic, virtually. Moreover, in vitro cytotoxic activity of these selected bio-degradation secondary products was examined against HepG2 and MCF7 cancer cell lines, where M33 and RS2 extract effects on acetaminophen/paracetamol bio-degradation products were safe, with higher IC50 on HepG2 and MCF7 than the acetaminophen/paracetamol IC50 of 108.5 μg/ml. Moreover, an in vivo oral acute single-dose toxicity experiment was conducted, to confirm these in vitro and in silico lower toxicity (better safety) than acetaminophen/paracetamol.

Phenyl Pentyl Ketone and m-isobutyl Methoxy Benzoate Produced by Streptomyces Chrestomyceticus ADP4 are Potent Antimicrobial Agents Displaying Broad Spectrum Activities.

The online version contains supplementary material available at 10.1007/s12088-023-01068-7.

Anti-Candida attributes and in-silico drug-likeness properties of phenyl 2'β, 6'β-trimethyl cyclohexyl ketone and phenyl nonanyl ether produced by Streptomyces chrestomyceticus ADP4.

To isolate and characterize anti-Candida compounds from soil actinobacterium Streptomyces chrestomyceticus ADP4 and to assess their drug likeness. Two anti-Candida compounds, Phenyl 2'α, 2'β, 6'β-trimethyl cyclohexyl ketone (1PB1) and Phenyl nonanyl ether (1PB2), were isolated from the metabolites produced by Streptomyces chrestomyceticus ADP4. Their structures were deduced by extensive analyses of spectral data obtained from liquid chromatography with tandem mass spectrometry (LCMS/MS), nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR) and ultraviolet (UV) spectroscopies. While both the compounds inhibited growth of the Candida spp., 1PB2 was effective in inhibiting biofilm formed by Candida albicans ATCC 10231. The compounds did not show any cytotoxicity against HepG2 cells and were found to be safe when predicted theoretically on rat model, bioaccumulation and mutagenicity by using the software: toxicity estimation software tool (TEST). The compounds displayed drug-like properties when analyzed by using SwissADME software. 1PB1 and 1PB2 are being reported for the first time from any natural source along with their anti-Candida properties. In-silico studies revealed their druggability and suitability to take up further work on the compounds for their possible application in treating Candida-associated infections. The increasing prevalence of Candidiasis associated with drug-resistant strains of Candida spp. highlighted the urgent need for discovery of new compounds with anti-Candida properties that could hold promise as potential drug candidate.

Proteomining-Based Elucidation of Natural Product Biosynthetic Pathways in Streptomyces

The genus Streptomyces is known to harbor numerous biosynthetic gene clusters (BGCs) of potential utility in synthetic biology applications. However, it is often difficult to link uncharacterized BGCs with the secondary metabolites they produce. Proteomining refers to the strategy of identifying active BGCs by correlating changes in protein expression with the production of secondary metabolites of interest. In this study, we devised a shotgun proteomics-based workflow to identify active BGCs during fermentation when a variety of compounds are being produced. Mycelia harvested during the non-producing growth phase served as the background. Proteins that were differentially expressed were clustered based on the proximity of the genes in the genome to highlight active BGCs systematically from label-free quantitative proteomics data. Our software tool is easy-to-use and requires only 1 point of comparison where natural product biosynthesis was significantly different. We tested our proteomining clustering method on three Streptomyces species producing different compounds. In Streptomyces coelicolor A3(2), we detected the BGCs of calcium-dependent antibiotic, actinorhodin, undecylprodigiosin, and coelimycin P1. In Streptomyces chrestomyceticus BCC24770, 7 BGCs were identified. Among them, we independently re-discovered the type II PKS for albofungin production previously identified by genome mining and tedious heterologous expression experiments. In Streptomyces tenebrarius, 5 BGCs were detected, including the known apramycin and tobramycin BGC as well as a newly discovered caerulomycin A BGC in this species. The production of caerulomycin A was confirmed by LC-MS and the inactivation of the caerulomycin A BGC surprisingly had a significant impact on the secondary metabolite regulation of S. tenebrarius. In conclusion, we developed an unbiased, high throughput proteomics-based method to complement genome mining methods for the identification of biosynthetic pathways in Streptomyces sp.

Albofungin and chloroalbofungin: antibiotic crystals with 2D but not 3D isostructurality.

The potent antibiotics albofungin [systematic name: (1S,4R,8aR)-13-amino-1,15,16-trihydroxy-4-methoxy-12-methyl-3,4,8a,13-tetrahydro-1H-xantheno[4',3',2':4,5][1,3]benzodioxino[7,6-g]isoquinoline-14,17(2H,9H)-dione, C27H24N2O9, 1] and its chlorinated analogue chloroalbofungin (the 11-chloro analogue, C27H23ClN2O9, 2) have been crystallized following their isolation from the bacterial strain Streptomyces chrestomyceticus and their structures determined by single-crystal X-ray diffraction. The novel N-aminoquinolone molecular arrangement shows N-N bond lengths of 1.4202 (16) and 1.424 (2) Å in 1 and 2, respectively. The regiochemistry of chloro substitution in the A-ring is para to the quinolone O atom, with a C-Cl bond length of 1.741 (2) Å. The absolute stereochemistry at three chiral centres of the xanthone rings (i.e. 10S, 13R and 19R) is confirmed. Both compounds crystallize in chiral Sohncke space groups consistent with enantiopurity, but are not fully isostructural. A preserved supramolecular construct (SC) confers two-dimensional (2D) isostructurality, but the SC self-associates via either a twofold screw operation in 1, giving a monoclinic P21 structure, or a twofold rotation in 2, affording a monoclinic C2 structure with a doubled unit-cell axis.

Microbial degradation, spectral analysis and toxicological assessment of malachite green by Streptomyces chrestomyceticus S20.

Malachite green (MG), a triphenylmethane dye is extensively used for coloring silk, aquaculture and textile industries, it has also has been reported toxic to life forms. This study aimed to investigate the biodegradation potential of MG by actinobacteria. The potent actinobacterial strain S20 used in this study was isolated from forest soil (Sabarimala, Kerala, India) and identified as Streptomyces chrestomyceticus based on phenotype and molecular features. Strain S20 degraded MG up to 59.65 ± 0.68% was studied in MSM medium and MG (300mgl-1) and degradation was increased (90-99%) by additions of 1% glucose and yeast extract into the medium at pH 7. The treated metabolites from MG by S20 characterized by FT-IR and GC-MS. The results showed MG has been degraded into nontoxic compounds evaluated by (1) phytotoxic assay on Vigna radiata, (2) microbial toxicity on Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Streptococcus sp. and Escherichia coli, (3) cytotoxicity assay in a human cell line (MCF 7). The toxicity studies demonstrated that the byproducts from MG degradation by S. chrestomyceticus S20 were no toxic to plants and microbes and less toxic to human cells as compared to the parent MG. Perhaps this is the first work reported on biodegradation of MG by S. chrestomyceticus which could be a potential candidate for the removal of MG from various environments.

Molecules and Metabolites from Natural Products as Inhibitors of Biofilm in Candida spp. pathogens.

BackgroundBiofilm is a critical virulence factor associated with the strains of Candida spp. pathogens as it confers significant resistance to the pathogen against antifungal drugs.MethodsA systematic review of the literature was undertaken by focusing on natural products, which have been reported to inhibit biofilms produced by Candida spp. The databases explored were from PubMed and Google Scholar. The abstracts and full text of the manuscripts from the literature were analyzed and included if found significant.ResultsMedicinal plants from the order Lamiales, Apiales, Asterales, Myrtales, Sapindales, Acorales, Poales and Laurales were reported to inhibit the biofilms formed by Candida spp. From the microbiological sources, lactobacilli, Streptomyces chrestomyceticus and Streptococcus thermophilus B had shown the strong biofilm inhibition potential. Further, the diverse nature of the compounds from classes like terpenoids, phenylpropanoid, alkaloids, flavonoids, polyphenol, naphthoquinone and saponin was found to be significant in inhibiting the biofilm of Candida spp.Conclusion: Natural products from both plant and microbial origins have proven themselves as a goldmine for isolating the potential biofilm inhibitors with a specific or multi-locus mechanism of action. Structural and functional characterization of the bioactive molecules from active extracts should be the next line of approach along with the thorough exploration of the mechanism of action for the already identified bioactive molecules.

Reclassification of Streptomyces rimosus subsp. paromomycinus as Streptomyces paromomycinus sp. nov.

Streptomyces rimosus is currently composed of two subspecies: Streptomyces rimosus subsp. rimosus and Streptomyces rimosus subsp. paromomycinus. The 16S rRNA gene similarity between type strains of these two subspecies is 99.03 %, whereas that between S. rimosus subsp. paromomycinus and Streptomyces chrestomyceticusis 100 %. To assess the taxonomic status of S. rimosus subsp. paromomycinus, genome sequencing was performed on the type strains of S. rimosus subsp. paromomycinus and S. chrestomyceticus. Digital DNA-DNA hybridization values between S. rimosus subsp. paromomycinus NBRC 15454T and S. rimosus subsp. rimosus ATCC 10970T and between S. rimosus subsp. paromomycinus NBRC 15454T and S. chrestomyceticus NBRC 13444T were 35.4 and 59.9 %, respectively, which are less than the thresholds for bacterial species delineation and indicate that S. rimosus subsp. paromomycinus is not S. rimosus, but an independent species different from S. rimosus and S. chrestomyceticus. In addition, phenotypic data also support that S. rimosus subsp. paromomycinus is distinct from S. chrestomyceticus. Therefore, S. rimosus subsp. paromomycinus should be reclassified as a novel species, for which we propose the name Streptomyces paromomycinus sp. nov. The type strain is NBRC 15454T (=ATCC 14827T=DSM 41429T=JCM 4541T=JCM 4871T=NRRL 2455T=VKM Ac-605T).

Polycyclic tetrahydroxanthones from Streptomyces chrestomyceticus BCC 24770

Three polycyclic tetrahydroxanthones, chrestoxanthones A−C, together with known albofungin and chloroalbofungin were isolated from the actinomycete Streptomyces chrestomyceticus BCC 24770. Their structures were elucidated by extensive spectroscopic analyses. Chrestoxanthone A was active against Curvularia lunata and Alternaria brassicicola, while all other isolated metabolites displayed broad antifungal activities against C. lunata, A. brassicicola, Colletotrichum capsici, and Colletotrichum gloeosporioides.

Strain selection, medium development and scale-up of toyocamycin production by streptomyces chrestomyceticus

The batch productivity (QTM) of the production of the nucleoside antibiotic toyocamycin (TM) by Streptomyces chrestomyceticus was increased ten-fold by selection of a UV generated mutant, optimization of pH, increasing incubation temperature from 28 °C to 36 °C, and addition of soy oil. Initial high oxygen transfer rates stimulated QTM maxima two-fold. Antibiotic production by the mutant strain, U190, however, appeared more shear sensitive than the parent culture FCRF 341 with maximum antibiotic titer being inversely related to impellor tip velocity, Tv. For this reason, scale-up could not be done at constant P/V or constant volumetric oxygen transfer. Instead, programming of impeller speed was evaluated in order to maintain optimal impeller tip velocity during scale-up. It was found that a low constant Tv maintained in scale-up in geometrically similar vessels was most beneficial for duplication of optimal antibiotic productivity, QTM. Pilot fermentations (120 dm3 scale) were used to determine coefficients of QTM variation from oxygen uptake rate (OUR) and total CO2 evolution data for monitoring of QTM variation during scale-up to the 12,000 dm3 scale. This technique allowed for on-line prediction of antibiotic titer and QTM from fermentor exhaust gas data.