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Metribuzin, a widely used triazine herbicide, persists in agricultural soils and poses significant environmental pollution threats globally. The aim of this study was to investigate the biodegradation of metribuzin by actinobacterial strains in vitro at different environmental conditions. From an initial screen of 12 actinobacterial strains, four bacteria exhibited robust growth in the presence of the metribuzin as the sole carbon source at 50 mg/L concentration. The optimization of metribuzin biodegradation under different conditions (pH, temperature and inoculum size) using a spectrophotometric method revealed that maximum degradation of metribuzin occurred at a pH of 7.2, a temperature 30 °C, and at an inoculum volume of 4%. Subsequent GC-MS validation confirmed the remarkable biodegradation capabilities of the actinobacterial isolates, where the strain C1 showed the highest rate of metribuzin degradation of 83.12%. Detailed phylogenetic identified the active strains as Streptomyces toxytricini (CH), Streptomyces stelliscabiei (B2), and two Streptomyces heliomycini (C1, C3). Structural analysis by ATR-FTIR spectroscopy confirmed the extensive biotransformation of the herbicide molecule. Our findings highlight the immense untapped potential of soil actinobacteria, particularly the Streptomyces heliomycini C1 strain, as versatile bioremediation agents for removing persistent agrochemical pollutants.

Glyphosate, also known as N-phosphonomethylglycine, is the herbicide that is widely used across the globe. As there are concerns over its potential toxicity to non-target soil species, there is a growing interest in identifying glyphosate-degrading microorganisms in soil. Biodegradation, by actinobacteria, is a very promising approach to eliminate this pesticide from contaminated environments. The present work isolated and identified actinobacteria capable of degrading glyphosate from Saharan agriculture, as well as determined how the application of this herbicide affects the abundance of actinobacteria present in soil. It was observed that the use of glyphosate led to an increased abundance of actinobacteria in the soil compared to the untreated soil. Among this population, an actinobacterial strain was isolated from glyphosate contaminated soil by the enrichment method, and was identified to possess the greatest capability to degrade glyphosate at 50 mg/L. The identification of this strain was achieved through a combination of cultural, morphological, biochemical, and molecular techniques. This included the use of 16S rDNA sequencing, leading to its successful classification as Streptomyces sp. strain SRH22. This strain was assigned the accession number OQ302556 by the National Center for Biotechnology Information (NCBI). A rapid, sensitive, and straightforward spectrophotometric technique was employed for the quantification of glyphosate. Results showed that the optimal biodegradation (90.2%) was obtained under a temperature of 30 degrees, a PH of 7.2, and an inoculum volume of 4% timed over six days. This work shows that the Streptomyces SRH22 presents good potentiality to be used as a bioremediation agent for agricultural soils in the Algerian Sahara.

Abstract Recently, cancer research protocols have introduced clinical-stage spirooxindole-based MDM2 inhibitors. However, several studies reported tumor resistance to the treatment. This directed efforts to invest in designing various combinatorial libraries of spirooxindoles. Herein, we introduce new series of spirooxindoles via hybridization of the chemically stable core spiro[3H-indole-3,2′-pyrrolidin]-2(1H)-one and the pyrazole motif inspired by lead pyrazole-based p53 activators, the MDM2 inhibitor BI-0252 and promising molecules previously reported by our group. Single crystal X-ray diffraction analysis confirmed the chemical identity of a representative derivative. Fifteen derivatives were screened for cytotoxic activities via MTT assay against a panel of four cancer cell lines expressing wild-type p53 (A2780, A549, HepG2) and mutant p53 (MDA-MB-453). The hits were 8h against A2780 (IC50 = 10.3 µM) and HepG2 (IC50 = 18.6 µM), 8m against A549 (IC50 = 17.7 µM), and 8k against MDA-MB-453 (IC50 = 21.4 µM). Further MTT experiments showed that 8h and 8j potentiated doxorubicin activity and reduced its IC50 by at least 25% in combinations. Western blot analysis demonstrated that 8k and 8m downmodulated MDM2 in A549 cells. Their possible binding mode with MDM2 were simulated by docking analysis.

Abstract The main concern of today's agricultural production around the world is a cleaner and greener approach to crop production. Streptomyces species with distinct characteristics can be found in soil. The current research focuses on Streptomyces species isolated from marine sediment samples. To evaluate the morphology and biochemical properties of the isolated Streptomyces strain ukm1, it was grown in Starch Casein Nitrate (SCN) agar medium. Morphological, biochemical, and 16s rRNA analysis were performed on the strain. Streptomyces sp. was identified based on these findings. The production of bioactive metabolites by strain nkm1 was carried out in five different fermentative media. After 10 days of incubation, M6 medium was found to be efficient and was extracted with ethyl acetate. The MIC values revealed that the ethyl acetate extract inhibited the growth of plant pathogenic fungi such as Phytophthora palmivora (31.25 g/ml), Aspergillus flavus (15.62 g/ml), Rhizoctonia solani (31.25 g/ml), and Cladosporium herbarum (31.25 g/ml). The GC-MS analysis of the ethyl acetate extract revealed 26 components, the major volatile bioactive compound being nonadecane.

Objectives: The search for new biocontrol agents, especially from natural sources, to control plant pathogens is a key area in tea plant protection research. Methods: Starch casein nitrate (SCN) agar was used to isolate the actinomycetes from the soil samples. These isolates were tested with modified version of the dual-culture method for antagonistic activity against Pestalotiopsis theae. The most bioactive isolate of actinomycets has been identified by biochemical, phisological, and morphological characterisation. Bioactivity of Streptomyces sp. SLR03 metabolites was measured in vitro and in vivo. The extract was eventually analyzed by GC–MS. Results: For the first time, an attempt has been made to isolate actinomycete species with bio-control potential from the river soil samples. A total of one hundred and seven actinomycete strains isolated and were evaluated for antagonistic potential against Pestalotiopsis theae using a dual-culture assay. Among the strains isolated, one strain SLR03 that showed potential and it was characterized. Further, the strain SLR03 was evaluated for antagonistic activity against P. theae both in vitro and in vivo. In in vitro assay, 86.15% and 93.85% mycelial growth inhibition was observed with cell-free filtrate and ethyl acetate extract of Streptomyces sp. SLR03, respectively. The ethyl acetate extract was further evaluated for its biocontrol activity against P. theae, it exhibited 80.39% reduction of disease incidence compared to the control. Further, the ethyl acetate extract were analyzed using GC–MS. The GCMS chromatogram exhibited 24 intense peaks consistently with 19 different compounds, 10 of which contain antifungal activity. Conclusions: This present study illustrates that Streptomyces sp. strain SLR03 is a prospective candidature for forthcoming biological control programme.

Background: Actinomycetes show an active role in microbial disease control and antimicrobial metabolism production and were shown the greatest potentialities as sources of antimicrobial agents. The past few decades, an extensive literature has accumulated on the production of bioactive compounds from actinomycetes, particularily genus Streptomyces. Methods: The actinomycetes were isolated with starch casein nitrate (SCN) agar medium. The prospective isolate was subjected to antimicrobial metabolites production. Further, the bio-extract was evaluated their biological properites by agar well diffusion assay and finally the extract was anaylized through GC–MS. Results: In the present study, isolated 9 actinomycetes and the isolates were examined for their antifungal activities. Of these nine isolates, the isolate MK_MSt033 picked out from the rest, hences, it showed significant control towards the selected microbial pathogens. The prospective strain MK_MSt033 was determined as Nocardiopsis sp. The strain displayed effective antimicrobial activities against both bacterial and fungal pathgoens such as Escherichia coli, Staphylococcus aureus, Pencillium sp., and Aspergillus flavus respectively. Subsequently the chemical nature of the compounds produced by the potential isolate MK_MSt033 and it was successfully determined by GC–MS and it were 18 compounds with different retention time. Conclusion: The identified isolate Nocardiopsis sp. MK_MSt033 exhibited potential antimicrobial activities against selected microbial pathogens. Thus, the soil inhabiting Nocardiopsis sp. has explored for pharmaceutically active compounds with promising medical applications.

Streptomyces antibioticus strain ess_amA8 was isolated from the insect Tapinoma simrothi, and was tested for the production of compounds that inhibit the growth of microorganisms. The cultural and physiological descriptions of the strain revealed that it belonged to the Streptomyces genus. The 16S rRNA gene from the Streptomyces isolate was sequenced, and its length was 1156 bp and it was submitted to Genbank (KF996507). According to molecular and morphological studies, the isolated strain was ultimately identified as strain ess_amA8 of Streptomyces antibioticus. The key compound was extracted from the strain ess_amA8, which was active in vitro, against a wide range of microorganisms, such as Staphylococcus aureus ATCC6538, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC-7839, Candida albicans, Fusarium moniliforme, Aspergillus niger, and Aspergillus flavus. The physico-chemical property of the purified antimicrobial compound analyzed and its proposed empirical formula was C27H25O13. According to the IUPAC name, this compound was identified as 5,7-diethoxy-2-(3-methoxy-4-methylphenyl)-3-[(2R,3S,4R,5R,6S)-3,4,5,6-tetrahydroxy-2-(hydroxymethyl)tetrahydro-2H-pyran-3-yl] oxy-4H-chromen-4-one, and was a quercetin 3-O-glucoside derivative. In summary, the present study highlights the fact that the purified quercetin 3-O-glucoside antimicrobial derivative, first report to this Streptomyces sp., and it is a flavanone glycoside. Keywords: Streptomyces antibioticus, Tapinoma simrothi, Quercetin, Flavanone glycoside

This study examined the ability of the green microalgae Chlorella vulgaris to remove arsenic from aqueous solutions. A series of studies was conducted to determine the optimal conditions for biological arsenic elimination, including biomass amount, incubation time, initial arsenic level, and pH values. At 76 min, pH 6, 50 mgL−1 metal concentration, and 1 gL−1 bio-adsorbent dosage, the maximum removal of arsenic from an aqueous solution was 93%. The uptake of As (III) ions by C. vulgaris reached an equilibrium at 76 min of bio-adsorption. The maximum adsorptive rate of arsenic (III) by C. vulgaris was 55 mg/gm. The Langmuir, Freundlich, and Dubinin–Radushkevich equations were used to fit the experimental data. The best theoretical isotherm of Langmuir, Freundlich, or/and Dubinin–Radushkevich for arsenic bio-adsorption by Chlorella vulgaris was determined. To choose the best theoretical isotherm, the coefficient of correlation was used. The data on absorption appeared to be linearly consistent with the Langmuir (qmax = 45 mgg−1; R2 = 0.9894), Freundlich (kf = 1.44; R2 = 0.7227), and Dubinin–Radushkevich (qD–R = 8.7 mg/g; R2 = 0.951) isotherms. The Langmuir and Dubinin–Radushkevich isotherms were both good two-parameter isotherms. In general, Langmuir was demonstrated to be the most accurate model for As (III) bio-adsorption on the bio-adsorbent. Maximum bio-adsorption values and a good correlation coefficient were observed for the first-order kinetic model, indicating that it was the best fitting model and significant in describing the arsenic (III) adsorption process. SEM micrographs of treated and untreated algal cells revealed that ions adsorbed on the algal cell’s surface. A Fourier-transform infrared spectrophotometer (FTIR) was used to analyze the functional groups in algal cells, such as the carboxyl group, hydroxyl, amines, and amides, which aided in the bio-adsorption process. Thus, C. vulgaris has great potential and can be found in eco-friendly biomaterials capable of adsorbing arsenic contaminants from water sources.

The mechanical characteristics of hybrid polypropylene composites may be enhanced by adjusting the fibre loading and ratio, according to this study. The hot press technique was utilised to generate a variety of composites with four different amounts of fibre loading. In addition, the fibre ratio in composites with a 20-weight-percent fibre loading was changed. The composites were characterised using Fourier transform infrared analysis as well as tensile, flexural, and hardness tests. In the composites that have been created, Fourier transform infrared examination showed that hemicelluloses, lignins, and moisture were present, all of which have the potential to reduce tensile strength. Fibre loading resulted in a decrease in tensile strength but an increase in Young’s modulus. With increasing fibre loading, flexural modulus and hardness rose, whereas flexural strength declined. The best mechanical qualities were found in a composite made primarily of arecanut and glass fibres, with a weight ratio of 1 : 3.

The primary goal of this work is to evaluate how BN and WC particles affect the mechanical properties and damage development behaviours of aluminum alloy-2048. Heat treatments for composites are also being investigated to improve mechanical properties. Tensile experiments reveal that BN particle reinforcement outperforms WC reinforcement in strength and flexibility for composites. T4 treatment, rather than traditional peak-aging treatment, is recommended for the composites (T6). The particle size distribution in 10v% WC/Al-2048 is the best in the three composites with the largest size of 16 µm and 80% of particles are from 6 to 10 µm. Tensile tests illustrate that 15v% BN/Al-2048 composite demonstrates a 9 and 14% rise in its ultimate tensile stress and 28 and 120% increases in its elongation. T4 heat treatment with an additional 0.6 percent prestrain can produce composites with the same UTS and 0.2 percent proof stress as T6 treatment, but the ultimate elongation below T4 treatment is over 100 percent more than that under T6 treatment. To make sense of the test results, an observation of the damage evolution behaviors of the reinforcing particles provides a concept that the composites’ strength is primarily determined by the balance between the reinforcing particles sharing the load and creating strain discontinuity in the matrix. The fraction of broken particles in the 20v% WC/Al-2048 composite as a function of strain is much higher than that in the 15v% BN/Al-2048 composite. Because of their tolerance for substantial strain at the interface, maximum K1c, and moderate thermal extension, BN elements can share a lot of loads and provide more excellent reinforcement than WC particles in terms of composite strength and flexibility.

The high occurrence of mycological resistance to conventional antifungal agents results in significant illness and death rates among immunodeficient patients. In addition, the underprivileged therapeutic results of conventional antifungal agents, besides the potential toxicity resulting from long term therapy necessitate the fabrication of efficient antimicrobial combinations. Hence, the objective of the present investigation is to synthesize, characterize and investigate the anticandidal action of green zinc oxide nanoparticles (ZnO-NPs) formulated using Camellia sinensis leaf extract against three candidal pathogens. The eco-friendly synthesized ZnO-NPs were characterized utilizing different physicochemical methods and their anticandidal potency was tested utilizing a disk diffusion assay. In this setting, the size of the biofabricated ZnO-NPs was detected using transmission electron microscope (TEM) micrographs, recording an average particle size of 19.380 ± 2.14 nm. In addition, zeta potential analysis revealed that the ZnO-NPs surface charge was −4.72 mV. The biogenic ZnO-NPs reveal the highest anticandidal activity against the C. tropicalis strain, demonstrating relative suppressive zones measured at 35.16 ± 0.13 and 37.87 ± 0.24 mm in diameter for ZnO-NPs concentrations of 50 and 100 μg/disk, respectively. Excitingly, Candida glabrata showed a high susceptibility to the biofabricated ZnO nanomaterials at both ZnO-NPs’ concentrations (50 and 100 μg/disk) compared to the control. Moreover, the biosynthesized ZnO-NPs revealed potential synergistic effectiveness with nystatin and terbinafine antifungal agents against the concerned strains. The maximum synergistic efficiency was noticed against the C. glabrata strain, demonstrating relative synergistic percentages of 23.02 and 45.9%, respectively. The biogenic ZnO-NPs revealed no hemolytic activity against human erythrocytes revealing their biosafety and hemocompatibility. Finally, the high anticandidal effectiveness of biogenic ZnO-NPs against the concerned candidal pathogens, as well as potential synergistic patterns with conventional antifungal agents such as nystatin and terbinafine, emphasize the prospective application of these combinations for the fabrication of biocompatible and highly efficient antifungal agents.

Streptomyces is recognized as a crucial generator of bioactive molecules that benefit humanity, such as antibiotics and other medications. The Streptomyces strain obtained from the gut of Apis mellifera yemintica was utilized in this investigation to screen for antibacterial and antiproliferative activities using secondary metabolites. On the basis of morphological and molecular identification, the isolated strain ess_amH1 was confirmed as Streptomyces sp., and phylogenetic tree construction revealed 96% sequence similarity with Streptomyces griseus. The ethyl acetate solvent extract generated from the strain ess_amH1 demonstrated high antibacterial activity against ATCC bacterial pathogens, as well as pathogenic yeast, according to the disc diffusion assay. The ethyl acetate solvent extract also induced dose-dependent cytotoxicity in breast cancer and hepatocarcinoma cell lines, with IC50 concentrations at 50 and 75 µg/mL, respectively. The findings confirm that the Streptomyces sp. strain ess_amH1 isolated from a competitive symbiotic habitat, i.e., the gut of A. mellifera yemintica, produces promising bioactive chemicals.

Silver-based nanostructures are suitable for many biomedical applications, but to be useful therapeutic agents, the high toxicity of these nanomaterials must be eliminated. Here, we biosynthesize nontoxic and ultra-small silver nanoclusters (rsAg@NCs) using metabolites of usnioid lichen (a symbiotic association of algae and fungi) that exhibit excellent antimicrobial activity against fluconazole (FCZ)-resistant Candida albicans that is many times higher than chemically synthesized silver nanoparticles (AgNPs) and FCZ. The rsAg@NCs trigger apoptosis via reactive oxygen species accumulation that leads to the loss of mitochondrial membrane potential, DNA fragmentation, chromosomal condensation, and the activation of metacaspases. The proteomic analysis clearly demonstrates that rsAg@NCs exposure significantly alters protein expression. Most remarkable among the down-regulated proteins are those related to glycolysis, metabolism, free radical scavenging, anti-apoptosis, and mitochondrial function. In contrast, proteins involved in plasma membrane function, oxidative stress, cell death, and apoptosis were upregulated. Eventually, we also established that the apoptosis-inducing potential of rsAg@NCs is due to the activation of Ras signaling, which confirms their application in combating FCZ-resistant C. albicans infections.