Search Results (226)

The copper contamination of terrestrial and aquatic ecosystems is a major global environmental problem. Copper is a metal used in many industrial and agricultural processes that is bioaccumulative and highly toxic, making its elimination, recovery and reuse of great interest for environmental sustainability. At the same time, the use of ubiquitous microorganisms is presented as a crucial tool in the field of the sustainability of mineral resources, which in many cases end up as bioaccumulative pollutants, since they can allow the recovery of metallic ions present in low concentrations and, in parallel, the reconversion of these into crystalline species that can be used in other technological fields. The potential of a ubiquitous microorganism, Penicillium sp. 8L2, to retain Cu(II) ions was investigated, as well as the ability of its cellular extract to synthesize CuO nanoparticles, which were subsequently evaluated as biocidal agents against five microorganisms. A response surface methodology was used to determine the optimal operating conditions of the biosorption process, setting the pH at 4.8 and the biomass concentration at 0.8 g/L and obtaining a maximum biosorption capacity at equilibrium of 25.79 mg/g for the Langmuir model. Different analytical techniques were used to study the biosorption mechanisms, which revealed the presence of surface adsorption and intracellular bioaccumulation phenomena involving different functional groups. The fungal cell extract allowed the successful synthesis of CuO-NPs with an average size of 22 nm. The biocidal tests performed with the nanoparticles showed promising values of minimum inhibitory concentrations between 62.5 and 500 µg/mL. Penicillium sp. 8L2 showed good potential for its application in the field of heavy metal bioremediation and for the green synthesis of nanoparticles useful in biomedicine. Full article

In this study, we investigated whether three microbial strains, Lactiplantibacillus plantarum J-135, Saccharomyces cerevisiae DAE-4, and Bacillus velezensis PBS-17, could be used to reduce mold growth and spoilage during the production of fermented feed. These microorganisms were isolated and characterized via an evaluation of their antibacterial activity, enzymatic activity, bile acid resistance, and acid tolerance. L. plantarum J-135 and S. cerevisiae DAE-4 demonstrated excellent acid tolerance and bile acid resistance, and L. plantarum J-135 exhibited antibacterial activity against Salmonella species. B. velezensis PBS-17 showed the greatest protease, cellulase, α-amylase, and phytase enzymatic activities, and displayed antibacterial activity against Fusarium solani, Aspergillus flavus, Penicillium sp., and Fusarium oxysporum. The three isolated strains were diluted to the same concentration (1:1:1) to create a culture solution, which was added to a standard feed (experimental group) to prepare fermented feed. This was compared with feed treated with a commercially available single probiotic preparation (control group 1) or a mixed microbial preparation that was composed of multiple strains, including B. subtilis. The feed treated with the single probiotic preparation spoiled after 21 days due to insufficient lactic acid bacteria growth, whereas the feed treated with the mixed microbial preparation exhibited mold growth after 14 days. The bacteria and fungi that cause spoilage during fermented feed production were effectively controlled in feed treated with L. plantarum J-135, S. cerevisiae DAE-4, and B. velezensis PBS-17. Therefore, the mixture of these three microbial strains may reduce the risk of spoilage during fermented silage and feed processing, thereby improving storage properties and stability. Full article

Mycotoxin contamination in agricultural goods is a major global problem due to its negative impact on human and animal health. The principal mycotoxin producers are fungal species from the genera Fusarium, Aspergillus, Alternaria, and Penicillium. The toxigenic fungal species produce the mycotoxins as secondary metabolites when they invade agricultural commodities during crop cultivation in the field (preharvest) or after harvesting or during transport and storage. This study was designed to investigate the levels of Fusarium mycotoxins, viz., fumonisin (FUM), zearalenone (ZEN), and deoxynivalenol (DON) in cereal grain samples collected from Muscat, Sultanate of Oman during 2023-24. A total of 90 cereal grain (wheat, corn, rice, barley) samples from local markets at Muscat, the Plant Quarantine Department, Oman, and Oman Flour Mills Company were analyzed using competitive enzyme immunoassay kits. Furthermore, Fusarium spp. associated with the contaminated grain samples were isolated, and their mycotoxin-producing potential was assessed. The results indicated that FUM, ZEN, and DON levels were below the detection limit (LOD) in 81%, 97%, and 44% of the samples, respectively. Two out of fifteen corn samples and one out of thirty-seven wheat samples tested exceeded the maximum permissible limit for FUM and ZEN, respectively, as set by the European Commission. A total of 19 Fusarium spp. associated with the contaminated grain samples were isolated and identified through molecular techniques. Sixteen isolates of F. verticillioides, one isolate of F. thapsinum, and two new Fusarium species were identified based on nuclear ribosomal DNA internal transcribed spacer and elongation factor 1-alpha sequences. Two isolates of F. verticillioides (FQD-1 and FQD-20) produced FUM levels exceeding 2000 µg kg⁻¹. The maximum ZEN concentration was observed in F. verticillioides FQD-20 (9.2 µg kg⁻¹), followed by F. verticillioides FQD-2 (2.8 µg kg⁻¹) and Fusarium sp. FOFMC-26 (2.5 µg kg⁻¹). All tested Fusarium strains produced DON, with levels ranging from 25.6 to 213 µg kg⁻¹, with F. thapsinum FQD-4 producing the highest level (213 µg kg⁻¹). To our knowledge, this is the first report on the occurrence of Fusarium mycotoxins and mycotoxigenic Fusarium spp. in food commodities in Oman. Full article

Fungal endophytes colonizing plant tissues are considered a reservoir of secondary metabolites that exhibit diverse bioactivities applicable in biomedicine. This study aims to reveal for the first time endophytic fungi associated with Keteleeria evelyniana as a potential source of bioactive compounds. A total of 24 fungal endophytes were successfully isolated from K. evelyniana and classified into 10 genera: Aspergillus, Penicillium, Fusarium, Xylaria, Talaromyces, Nodulisporium, Apiospora, Neopestalotiopsis, Diaporthe, and Hypoxylon. Screening for antimicrobial activity revealed that 8 out of 24 ethyl acetate extracts inhibited antimicrobial activity against at least one tested pathogen. Among them, Xylaria sp. KET18 showed the most potent antimicrobial activity with inhibition diameters ranging from 16.5 to 21.5 mm. In addition, the KET18 extract showed the most significant cytotoxic effects against A549 (IC₅₀ = 18.8 ± 3.1 µg/mL) and MCF7 cell lines (IC₅₀ = 24.1 ± 2.5 µg/mL). The KET18 extract showed moderate antioxidant activity against hydroxyl and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The chemical characterization and structural elucidation indicated the presence of four bioactive compounds that have not been found in fungi, including methyl pyroglutamate, prunetin, macrolactin A, and macrolactin F. These findings demonstrated that K. evelyniana is a host of endophytic fungi with antimicrobial, anticancer, and antioxidant potential. Full article

The issue of the microbiological spoilage of bakery products with an extended shelf life declared by the producer was the reason for searching for an effective solution. The aim of the investigation was to find the sources of infection, identify microorganisms causing product spoilage, and propose ways to eliminate the problem without the use of chemical preservatives in the product. It was found that the dominant contaminating microorganisms are yeasts of the genus Hyphopichia sp., Saccharomyces sp., and Candida spp., as well as molds—Aspergillus spp. and Penicillium spp. The microbiological quality of the production environment was assessed, and as a remedial action, a disinfection process was carried out. The influence of gas composition in MAP (modified atmosphere packaging) and the use of ethanol during packaging on the incidence of yeast or mold occurrence was checked. The effectiveness of using sourdough was also tested. The best results were achieved by using sourdough obtained with selected starter cultures and using a gas mixture for packaging in the proportion of 70% carbon dioxide and 30% nitrogen, without the addition of ethanol. These conditions ensured the expected shelf life of bakery products while maintaining their quality. Full article

This study investigated the phytochemical profile and evaluated the antimicrobial and insecticidal properties of Eucalyptus camaldulensis Dehn. essential oil (EC-EO) from Algeria, using in vitro and in silico approaches. The yield of EC-EO was 0.27%, with gas chromatography-mass spectrometry (GC-MS) revealing spathulenol (58.24%), cryptone (17.22%), and o-cymene (15.53%) as the major compounds. EC-EO exhibited notable antibacterial activity, particularly against Salmonella typhimurium (14 ± 1.00 mm) and Staphylococcus aureus (14.5 ± 0.50 mm). It also showed effective antifungal activity against Penicillium sp. (11.5 ± 0.49 mm), Candida albicans (11.2 ± 0.29 mm), and Aspergillus fumigatus (9.8 ± 0.27 mm). Insecticidal assays against Tribolium castaneum were conducted using contact toxicity, fumigation toxicity, and repellent activity methods. The median lethal concentration (LC50) for contact toxicity was 0.011 μL/insect after 72 h, while the fumigation test had an LC50 of 122.29 μL/L air. Repellent activity tests showed percentage repellency (PR) values exceeding 80% after 6 h. The molecular geometry and electronic properties of the main compounds were studied using density functional theory (DFT) calculations. In addition, the interaction mode and binding affinity of these molecules with three key enzymes involved in antimicrobial activity, DNA gyrase, dihydrofolate reductase (DHFR) and Tyrosyl-tRNA synthetase (TyrRS), were explored by molecular docking. Full article

Fungal endophytes, symbiotic microorganisms residing within plants, are renowned for producing bioactive secondary metabolites with diverse beneficial properties. We investigated the antimicrobial potential of fungal endophytes isolated from Solanum mauritianum, an invasive weed, against clinically significant bacterial pathogens. Selected fungal endophytes (Penicillium chrysogenum, Fusarium sp., and Paracamarosporium leucadendri) were isolated from the plant’s leaves and fruits. Their crude extracts were tested against various referenced strains, such as Mycobacterium species (M. smegmatis ATCC 607 and M. bovis ATCC 27290), Staphylococcus aureus ATCC 6571, Bacillus subtilis ATCC 11774, Klebsiella species (K. pneumoniae ATCC 10031 and K. oxytoca ATCC 8724), Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 10145, using the Kirby-Bauer disk diffusion method. Resazurin Microtiter Assay was used for the determination of the minimum inhibitory concentration. The chemical nature of the secondary metabolites in the crude extracts produced by fungal endophytes was evaluated using high-resolution liquid chromatography–mass spectrometry (LC-MS) using water and acetonitrile gradient. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) was employed for untargeted metabolomics. LC-QTOF-MS/MS identified 63 bioactive compounds across the three endophytes. P. chrysogenum had the highest activity against S. aureus and M. smegmatis (1.15 mg/mL and 0.02 mg/mL, respectively), while P. leucadendri demonstrated moderate activity against M. smegmatis (2.91 mg/mL) and E. coli (1.16 mg/mL). Fusarium sp. exhibited the broadest spectrum of antibacterial activity, with MIC values ranging from 0.03 mg/mL (B. subtilis) to 10 mg/mL (M. smegmatis). P. leucadendri produced 29 metabolites, Fusarium sp. had 23 identified metabolites, and a total of 11 metabolites were identified from P. chrysogenum. The fruits of the plant, accounting for 60%, appeared to be the most abundant in the endophyte diversity when compared to the stems and leaves. This study highlights the potential of fungal endophytes from S. mauritianum as a source of novel bioactive compounds, particularly against multidrug-resistant pathogens, contributing to the ongoing efforts to combat antimicrobial resistance. Full article

The accumulation of microplastics (MPs) in the environment has been a bottleneck for scientific society. Several approaches have been described as possibilities for reducing MPs in aquatic and terrestrial ecosystems; however, most of them are not environmentally friendly. Filamentous fungi (Ff) cells are currently considered a promising solution as a treatment for MPs. Therefore, the present study reports the potential ability of Ff isolated from mangrove sediments to biodegrade low-density polyethylene MPs (LDPE_MPs). Six Ff strains were grown in batch cultures for 28 days, and one of them, Aspergillus sp. (AQ3A), showed the most prominent profile to biodegrade polymeric compounds. After morphological and molecular analysis, all strains were identified as belonging to the genera Aspergillus (MQ1C, AQ2A and AQ3A), Penicillium (MQ1A), and Trichoderma (MQ1B and MQ2A). The strain Aspergillus sp. (AQ3A) showed the most promising results with a LDPE_MPs reduction rate of 47% and biomass formation of 0.0890 g·mL⁻¹. Complementary studies with Aspergillus sp. (AQ3A) using Fourier-transform infrared spectroscopy (FTIR) highlighted changes in the molecular structure of LDPE_MPs. These results indicate that Ff can contribute to the biodegradation of LDPE_MPs. However, other parameters, mainly associated with the enzymes that are involved in this biodegradation process, need to be explored. Full article

The objective of this research was to investigate natural products for their potential against pathogenic microorganisms. Sabinene hydrate (SH), a monoterpenoid, is synthesised by numerous different plants as a secondary metabolite. At present, there is a lack of definite investigations regarding the antimicrobial activity of SH itself and its different isomers. The antimicrobial effects of commercially available SH (composed mainly of trans-isomer) were evaluated within a range of concentrations in three types of contact tests: solid and vapor diffusion and the macro-broth dilution method. Moreover, the effects of SH on the rate of linear growth and spore germination were also examined. Ethanolic SH solutions were tested against an array of microorganisms, including blue-stain fungi (Ceratocystis polonica, Ophiostoma bicolor, O. penicillatum), frequently originating from bark beetle galleries; three fungal strains (Musicillium theobromae, Plectosphaerella cucumerina, and Trichoderma sp.) isolated from a sapwood underneath bark beetle galleries (Ips typographus) on spruce (Picea abies) stems; Verticillium fungicola, isolated from diseased I. typographus larvae; two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa); five yeasts (Candida albicans, C. krusei, C. parapsilosis, Saccharomyces cerevisiae, and Rhodotorula muscilaginosa), and two saprophytic fungi (Aspergillus niger and Penicillium notatum). In solid agar disc diffusion tests, Gram-positive bacteria exhibited greater susceptibility to SH than Gram-negative bacteria, followed by yeasts and fungi. The most resistant to SH in both the disc diffusion and broth macro-dilution methods were P. aeruginosa, A. niger, and Trichoderma sp. strains. Blue-stain fungi and fungi isolated from the Picea sapwood were the most resistant among the fungal strains tested. The minimum inhibition concentrations (MICs) generated by SH and determined using a disc volatilization method were dependent on the fungal species and played an important role in the development of microorganism inhibition. The two Gram-positive bacteria, B. subtilis and S. aureus (whose MICs were 0.0312 and 0.0625 mg/mL, respectively), were the organisms most susceptible to SH, followed by the Gram-negative bacterium, E. coli (MIC = 0.125 mg/mL) and two yeasts, C. albicans and C. kruei (MIC was 0.125 mg/mL and 0.25 mg/mL, respectively). C. parapsilosis (MIC = 0.75 mg/mL) was the yeast most resistant to SH. The investigation of antimicrobial properties of plant secondary metabolites is important for the development of a new generation of fungicides. Full article

Two new C₂₃-steroids derivatives, cyclocitrinoic acid A (1) and cyclocitrinoic acid B (2), and a new isocoumarin metabolite, (3R,4S)-6,8-dihydroxy-3,4,5-trimethyl-7-carboxamidelisocoumarin (10), together with 12 known compounds (3–9, 11–15) were isolated from the mangrove-sediment fungus Penicillium sp. SCSIO 41429. The structures of the new compounds were comprehensively characterized by 1D and 2D NMR, HRESIMS and ECD calculation. All isolates were evaluated for pancreatic lipase (PL) inhibitory and antioxidant activities. The biological evaluation results revealed that compounds 2, 14 and 15 displayed weak or moderate inhibition against PL, with IC₅₀ values of 32.77, 5.15 and 2.42 µM, respectively. In addition, compounds 7, 12 and 13 showed radical scavenging activities against DPPH, with IC₅₀ values of 64.70, 48.13, and 75.54 µM, respectively. In addition, molecular docking results indicated that these compounds had potential for PL inhibitory and antioxidant activities, which provided screening candidates for antioxidants and a reduction in obesity. Full article

Three new polyketides, including three ester derivatives (1, 3, and 5) and a new natural product, which was a benzoquinone derivative, embelin A (4), together with nine known ones (2 and 6–13), were isolated from the mangrove-derived fungus Penicillium sp. SCSIO 41411. Their structures were determined by detailed NMR and MS spectroscopic analyses. The X-ray single-crystal diffraction analysis of 4 was described for the first time. Compound 9 displayed obvious inhibition against PDE4 with an inhibitory ratio of 40.78% at 10 μM. Compound 12 showed DPPH radical scavenging activity, with an EC₅₀ of 16.21 µg/mL, compared to the positive control (ascorbic acid, EC₅₀, 11.22 µg/mL). Furthermore, compound 4 exhibited cytotoxicity against PC-3 and LNCaP with IC₅₀ values of 18.69 and 31.62 µM, respectively. Full article

To elucidate the biological mechanisms driving the growth of various pumpkin varieties to different sizes under identical management conditions while in the same field, the soil microbial community structures in the rhizospheres of giant-pumpkin (GP) and small-pumpkin (SP) varieties were analyzed. The results revealed that a significantly higher abundance of bacterial communities could be detected in the rhizospheres of the giant pumpkin varieties, such as Gemmatimonadota, norank__f__norank__o_Gaiellales, norank__f__Gemmatimonadaceae, Bryobacter, Sphingomonas, norank__f__JG30-KF-AS9, and norank__f__norank__o___Elsterales, than in those of the small-sized pumpkins. Additionally, norank_f__norank_o__Elsterale, Ellin6067, norank_f__67-14, and Chujaibacter were unique dominant soil bacteria genera in the rhizospheres of the giant pumpkins. By contrast, Arthrobacter, norank_f__Roseiflexaceae, unclassified_f__Rhizobiaceae, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Nocardioides, Mycobacterium, norank_f__norank_o__Vicinamibacterales, and Burkholderia-Caballeronia-Paraburkholderia were the unique dominant soil bacterial genera in the rhizospheres of the small pumpkins. Moreover, at the fungal genus level, unclassified_c__Chytridiomycetes, Podosphaera, and Colletotrichum presented significant differences between the giant-pumpkin (GP) and small-pumpkin (SP) rhizospheres. In addition, unclassified__p__Rozellomycota, unclassified__c__Chytridiomycetes, Penicillium, and unclassified__f__Chaetomiaceae were unique dominant soil fungal genera in the rhizospheres of the giant pumpkins (GPs). By contrast, Podosphaera, Colletotrichum, unclassified__f__Plectosphaerellaceae, unclassified__o_Boletales, Scytalidium, unclassified__p__Rozellomycota, and unclassified__o_Agaricales were the unique dominant soil fungal genera in the rhizospheres of the small pumpkins (SPs). PICRUSt and FUNGuild functional prediction analyses revealed that the giant-pumpkin rhizosphere microbial community had significantly increased translation, ribosomal structure and biogenesis, nucleotide transport and metabolism, defense mechanisms, replication, recombination and repair, wood saprotroph, and undefined saprotroph levels. The above results suggest that the soil microbial compositions differed between the rhizospheres of the giant- (GP) and small-pumpkin (SP) varieties, even though the plants were grown in the same field under identical management conditions. Meanwhile, bacterial genera such as norank_f__norank_o__Elsterale, Ellin6067, norank_f__67-14, and Chujaibacter, in addition to fungal genera such as unclassified__p__Rozellomycota, unclassified__c__Chytridiomycetes, Penicillium, and unclassified__f__Chaetomiaceae, can be speculated as potential soil functional micro-organisms associated with improved pumpkin size. Full article

Four new polyketides, namely furantides A–B (1–2), talamin E (3) and arugosinacid A (4), and two known polyketides were obtained from the mangrove-derived fungus Penicillium sp. HDN15-312 using the One Strain Many Compounds (OSMAC) strategy. Their chemical structures, including configurations, were elucidated by detailed analysis of extensive NMR spectra, HRESIMS and ECD. The DPPH radicals scavenging activity of 3, with an IC₅₀ value of 6.79 µM, was better than vitamin C. Full article

Endophytic fungi, residing within plants without causing disease, are known for their ability to produce bioactive metabolites with diverse properties such as antibacterial, antioxidant, and antifungal activities, while also influencing plant defense mechanisms. In this study, five novel endophytic fungi species were isolated from the leaves of Psychotria poeppigiana Müll. Arg., a plant from the Rubiaceae family, collected in the tropical Amazon region of Bolivia. The endophytic fungi were identified as a Neopestalotiopsis sp., three Penicillium sp., and an Aspergillus sp. through 18S ribosomal RNA sequencing and NCBI-BLAST analysis. Chemical profiling revealed that their extracts obtained by ethyl acetate contained terpenes, flavonoids, and phenolic compounds. In a bioautography study, the terpenes showed high antimicrobial activity against Escherichia coli. Notably, extracts from the three Penicillium species exhibited potent antibacterial activity, with minimum inhibitory concentration (MIC) values ranging from 62.5 to 2000 µg/mL against all three pathogens: Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis (both Gram-positive and Gram-negative bacteria). These findings highlight the potential of these endophytic fungi, especially Penicillium species as valuable sources of secondary metabolites with significant antibacterial activities, suggesting promising applications in medicine, pharmaceuticals, agriculture, and environmental technologies. Full article

Cancer is a threatening disease that needs strong therapy with fewer side effects. A lot of different types of chemotherapy or chemo-drugs are used in cancer treatments but have many side effects. The increasing number of antibiotic-resistant microorganisms requires more study of new antimicrobial compounds and delivery and targeting strategies. This work aims to isolate and identify Azotobacter sp., and extract alginate from Azotobacter sp. As well as fabricating selenium nanoparticles using ascorbic acid as reducing agent (As/Se-NPs), and loading extracted alginate with selenium nanoparticles (Alg-Se-NCMs). The As/Se-NPs and Alg-Se-NCMs were categorized by TEM, EDX, UV–Vis spectrophotometry, FT-IR, and zeta potential. The antifungal activities of both As/Se-NPs and Alg-Se-NCMs were investigated against some human pathogen fungi that cause skin infection such as Aspergillus niger (RCMB 002005), Aspergillus fumigatus (RCMB 002008), Cryptococcus neoformans (RCMB 0049001), Candida albicans (RCMB 005003), and Penicillium marneffei (RCMB 001002). The anticancer activities were determined against HCT-116 colorectal cancer and Hep G2 human liver cancer cells. UV spectra of As/Se-NPs and Alg-Se-NCMs confirmed a surface plasmon resonance at 269 and 296 nm, and zeta potential has negative charges −37.2 and −38.7 mV,. Both As/Se-NPs and Alg-Se-NCMs were hexagonal, size ranging from 16.52 to 97.06 and 17.29 to 44.2. Alg-Se-NCMs had anticancer activities against HCT-116 and HepG2. The Alg-Se-NCMs possessed the highest antifungal activities against Cryptococcus neoformans, followed by Aspergillus niger, but did not possess any activities against Penicillium marneffei. Alginate-capped selenium nanoparticles can be used as antifungal and anticancer treatments. Full article