Search Results (373)

This study aimed to evaluate solid-state fermentation (SSF) as a sustainable approach for the simultaneous detoxification of olive pomace (OP) and the production of industrially relevant enzymes. OP, a semisolid byproduct of olive oil extraction, is rich in lignocellulose and phenolic compounds, which limit its direct reuse due to phytotoxicity. A native strain of Aspergillus sp., isolated from OP, was employed as the biological agent, while grape pomace (GP) was added as a co-substrate to enhance substrate structure. Fermentations were conducted at two scales, Petri dishes (20 g) and a fixed-bed bioreactor (FBR, 2 kg), under controlled conditions (25 °C, 7 days). Key parameters monitored included dry and wet weight loss, pH, color, phenolic content, and enzymatic activity. Significant reductions in color and polyphenol content were achieved, reaching 68% in Petri dishes and 88.1% in the FBR, respectively. In the FBR, simultaneous monitoring of dry and wet weight loss enabled the estimation of fungal biotransformation, revealing a hysteresis phenomenon not previously reported in SSF studies. Enzymes such as xylanase, endopolygalacturonase, cellulase, and tannase exhibited peak activities between 150 and 180 h, with maximum values of 424.6 U·g⁻¹, 153.6 U·g⁻¹, 67.43 U·g⁻¹, and 6.72 U·g⁻¹, respectively. The experimental data for weight loss, enzyme production, and phenolic reduction were accurately described by logistic and first-order models. These findings demonstrate the high metabolic efficiency of the fungal isolate under SSF conditions and support the feasibility of scaling up this process. The proposed strategy offers a low-cost and sustainable solution for OP valorization, aligning with circular economy principles by transforming agro-industrial residues into valuable bioproducts. Full article

The aim of this work is to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) against oral MDR (multi-drug-resistant) Candida spp. infections related to orthodontic treatment with palatal expanders through in vitro study. Methods: PDT protocol: Curcumin + H₂O₂ was used as a photosensitizer activated by a 460 nm diode LED lamp, with an 8 mm blunt tip for 2 min in each spot of interest. In vitro simulation: A palatal expander sterile device was inserted into a custom-designed orthodontic bioreactor, realized with 10 mL of Sabouraud dextrose broth plus 10% human saliva and infected with an MDR C. albicans clinical isolate CA95 strain to reproduce an oral palatal expander infection. After 48 h of incubation at 37 °C, the device was treated with the PDT protocol. Two samples before and 5 min after the PDT process were taken and used to contaminate a Petri dish with a Sabouraud field to evaluate Candida spp. CFUs (colony-forming units). Results: A nearly 99% reduction in C. albicans colonies in the palatal expander biofilm was found after PDT. Conclusion: The data showed the effectiveness of using aPDT to treat palatal infection; however, specific patient oral micro-environment reproduction (Ph values, salivary flow, mucosal adhesion of photosensitizer) must be further analyzed. Full article

Sunflower (Helianthus annuus L.) is an important oilseed crop in Northwest China, exhibiting resistance to salt and drought. Mining its excellent tolerance genes can be used for breeding. However, the current platforms for identifying gene function in sunflower is inadequate. The transient transformation system, which can rapidly validate gene function, shows promising prospects in research. In this study, we established an efficient transient expression transformation system for sunflower using three methods: Agrobacterium-mediated infiltration, injection, and ultrasonic-vacuum. The detailed procedures were as follows: Agrobacterium GV3101 carrying a GUS reporter gene on the pBI121 vector with an OD₆₀₀ of 0.8 as the bacterial suspension and 0.02% Silwet L-77 as the surfactant were utilized in all three approaches. For the infiltration method, seedlings grown hydroponically for 3 days were immersed in a bacterial suspension containing 0.02% Silwet L-77 for 2 h; for the injection method, the same solution was injected into the cotyledons of seedlings grown in soil for 4 to 6 days. Subsequently, the seedlings were cultured in the dark at room temperature for three days; for the ultrasonic-vacuum method, seedlings cultured in Petri dishes for 3 days were first subjected to ultrasonication at 40 kHz for 1 min, followed by vacuum infiltration at 0.05 kPa for 5–10 min. Agrobacterium-mediated transient transformation efficiency achieved by the three methods exceeded 90%, with gene expression being sustained for at least 6 days. Next, we employed the infiltration-based sunflower transient transformation technology with the Arabidopsis stable transformation platform to confirm salt and drought stress tolerance of candidate gene HaNAC76 from sunflower responding to various abiotic stresses. Altogether, this study successfully established an Agrobacterium-mediated transient transformation system for sunflower using these three methods, which can rapidly identify gene function and explore the molecular mechanisms underlying sunflower’s resistance traits. Full article

In the present work, the antimicrobial efficacy of Thymus vulgaris essential oil (EO) was investigated on Alternaria alternata strain BNR; a paper biodeteriogen was used as a model for a contaminated library. The influence of EO volume and diffusion modality, treatment duration, and inoculum age was evaluated in the vapor phase. In Petri dish screening, the influence of different EO volumes (5, 7.5, and 10 μL) on the microbial growth lag phase was investigated, and the growth inhibition period was established. The most effective treatment (10 μL EO) was then scaled up in a glass airtight container of 2650 cm³; a cold diffusion method was applied in order to quickly reach the maximum concentration of active compounds in the vapor phase. These tests demonstrated that EO efficacy is affected by the inoculum age and the contact time, and that the treatment should be performed as early as is feasible. A mycostatic effect was confirmed to be proportional to the utilized EO volume and independent from the treatment method. The information obtained in the present work will be applied to the set-up of an EO treatment in a library characterized by different levels of air contamination. Full article

Root-emitted volatile organic compounds (VOCs) play a critical role in below-ground ecological interactions by mediating communication between plants, pests, and their natural enemies. This study investigates the chemotactic behavior of three slug-parasitic nematode species—Phasmarhabditis papillosa, Oscheius myriophilus, and Oscheius onirici—in response to four carrot (Daucus carota) root-derived VOCs: α-pinene, terpinolene, bornyl acetate, and 2-ethyl-1-hexanol. Using a modified Petri dish assay, infective juveniles (IJs) were exposed to each compound across four concentrations (pure, 1000 ppm, 10 ppm, and 0.03 ppm), and their directional movement was quantified using a chemotaxis index (CI). The results revealed strong species-specific and concentration-dependent patterns. O. myriophilus exhibited the highest motility and repellency, particularly toward bornyl acetate and terpinolene, indicating its potential for use in VOC-guided biocontrol strategies. O. onirici showed moderate but consistent attraction to most VOCs, while P. papillosa exhibited generally weak or repellent responses, especially at higher concentrations. None of the compounds tested functioned as strong attractants (CI ≥ 0.2), suggesting that plant-derived VOCs alone may not be sufficient to direct nematode recruitment under field conditions. However, their integration with other biotic cues could enhance nematode-based “lure-and-infect” systems for sustainable slug control in carrot cropping systems. Full article

Horticulture and agriculture are facing the challenge of growing healthy and high-quality crops. Plant extracts are currently being widely investigated as an alternative means of plant protection. Interest in these measures has increased in order to reduce the use of chemical pesticides, environmental pollution, and adverse effects on human health. Also, due to the goals of the European Green Deal and the decreasing use of chemical pesticides, it has become essential to look for safer alternatives. The aim of this study was to investigate the inhibitory effect of plant extracts of clove (Syzygium aromaticum L.) and rosemary (Rosmarinus officinalis L.) against Colletotrichum acutatum and Botrytis cinerea plant pathogens and to evaluate fungal pathogens recovery after the exposure to the extract. The plant extracts (PEs) were obtained by subcritical CO₂ extraction. The inhibitory effect of PEs was investigated in vitro at concentrations of 1200, 1600, 2000, 2400, 2800, and 3000 μL/L. Petri dishes were incubated at 25 ± 2 °C, and the mycelial growth of fungal pathogens was evaluated at 2, 4, and 7 days after inoculation (DAI). Reinoculation was then performed. The research showed that both plant extracts had an antifungal effect. However, clove PE was more effective. This allows us to say that plant-based measures can inhibit plant pathogens, but it is essential to determine the optimal concentrations and test them with different pathogens. Full article

The global market size of animal parasiticides was valued at USD 12.9 billion in 2024. Animal deworming only results in temporary cures with little to no preventive effects; therefore, a strategy that combines animal deworming with prevention is essential in improving the control of helminths. The effectiveness of co-administrating curative and preventive agents and their compatibility were considered based on the parasitophagous fungus Mucor circinelloides, which was developed in edible agar–agar (red seaweed)-carrying dewormers. Accordingly, Petri dishes were prepared with either a biopolymer alone (control, G-C) or with the anthelmintic piperazine (550, 1102, 2210, and 5500 mg/plate) or levamisole (37.5, 75, 150, and 300 mg/plate) and were used to culture the fungus Mucor circinelloides. Strong fungal growth and high numbers of spores were observed in the presence of the anthelmintics. No differences were measured between the control plates and those containing parasiticide drugs. Similar mycelial growth patterns and sporogenesis rates were recorded for different amounts of each anthelmintic. In conclusion, this novel formulation based on biopolymers containing anthelmintics and enriched with the parasitophagous fungus represents a highly promising tool to consider for jointly deworming animals and minimizing the risks of helminth infection. Further studies are in progress to confirm these in vitro results. Full article

With the aim of developing an efficient propagation method for the exploitation of Thymelaea hirsuta and T. artonraira ssp. tartonraira in the xeriscaping and pharmaceutical industry, the effects of the following were examined on the in vitro germination of their seeds: (i) pretreatment (mechanical and chemical scarification or immersion in hot water; (ii) incubation temperature (5–30 °C); (iii) incubation light conditions (16 h photoperiod or continuous darkness); (iv) storage period at room temperature and darkness (up to 24 months). Seeds collected for two years from the same wild plants in Greece were surface-sterilized with a 15% commercial bleach solution for 15 min after the abovementioned treatments and placed for germination in Petri dishes containing a half-strength MS medium in growth chambers. The rate and final percentage of germination were recorded. For both species, scarification after immersion in concentrated H₂SO₄, preferably for 20 min, was necessary for seed germination, which indicates coat dormancy. Higher germination percentages were observed at temperatures of 10–20 °C, under continuous darkness for T. hirsuta (79–100%) and regardless of photoperiod for T. tartonraira (73–90%). Long storage reduced germination of only T. tartonraira (54–68% at optimum temperatures, 23 months after harvest), while T. hirsuta seeds stored for 5 months germinated at significantly lower percentages (40% maximum) compared to seeds stored for 9–24 months, revealing a dry after-ripening process. Seeds of both species harvested at different years showed stable behavior in terms of germination. For both species, an effective seed propagation protocol suitable for their exploitation as ornamental and landscape plants was developed. Full article

Νatural compounds such as lactic, acetic, formic, and oxalic acid and thymol are currently registered for use against Varroa destructor in apiaries in Europe. Complex botanical extracts are yet to be authorized, despite their beneficial ecofriendly profile and advantages in terms of resistance management. This study examined the fumigant activity of the essential oil (EO) of oregano, clove, lavender, dittany, bay laurel, sweet orange, peppermint, blue gum, and lemon balm against V. destructor in laboratory bioassays (Petri dishes). The most effective EOs were those of Origanum vulgare, Syzygium aromaticum, and Origanum dictamnus. These three EOs yielded 33.75% carvacrol, 58.64% eugenol, and 69.77% carvacrol and exhibited significant activity from 18 h of exposure to 0.0013 μL/cm until 48 h of exposure to 0.0068 μL/cm³. Origanum vulgare’s first calculated LC₅₀ value was 0.003 μL/cm³ after 24 h of mites’ exposure to EO vapors. The LC₅₀ values stabilized for oregano, clove, and dittany at 0.001, 0.002, and 0.002 μL/cm³ of 24 h exposure, respectively. This first indication of fumigant miticidal activity in Petri dishes is a promising first step before scaling up to field experiments. Full article

Classifying newly formed colonies is instrumental in uncovering sources of infection and enabling precision medicine, holding significant clinical value. However, due to the ambiguous features of early-stage colony images in culture dishes, conventional computer vision (CV) classification algorithms are often ineffective. To achieve accurate and efficient colony classification, this paper proposes a high-precision method based on Persistent Homology (PH) and an improved EfficientNet. Specifically, (1) a PH feature extraction algorithm is applied to Candida albicans (CA) and Staphylococcus epidermidis (SE) colonies cultured for 18 h in Petri dishes to capture their topological information. (2) The Mobile Inverted Bottleneck Convolution (MBConv) module in EfficientNet is modified, enhancing the attention mechanism to better handle local small targets. (3) A novel self-attention mechanism named the Spatial and Contextual Transformer (SCoT), which is introduced to process information at multiple scales, increasing the resolution in orthogonal directions of the image and the aggregation capability of feature maps. The proposed approach achieves a high accuracy of 98.64%, a 10.29% improvement over the original classification model. The research findings indicate that this method can effectively classify colonies with high efficiency. Full article

The aim of this research was to compare the growth-inhibitory effect of halloysite-based nanotubes preloaded with sodium fluoride incorporated into two commercial glass ionomers (Vitrebond 3M^TM and Ionobond VOCO) for indirect pulp capping. Methods: Sixty samples were prepared and were distributed into two control groups, two positive control groups and two experimental groups. A total of 10% of the total weight of ionomer powder required to prepare each sample was replaced with nanotubes that had been preloaded at 2000 parts per million (minimum inhibitory dose for Streptococcus mutans established in this study using the McFarland index). The growth-inhibitory effect was determined by placing the samples in Petri dishes inoculated with S. mutans for 24 h at 37 °C. Results: Regarding the control groups, only Vitrebond demonstrated a growth inhibition zone; both experimental groups showed an inhibitory effect, and statistical differences were observed when the experimental Ionobond group and control groups were compared. Conclusions: The ionomers reinforced with fluorine-modified nanotubes showed an adequate inhibitory effect on Streptococcus mutans. Full article

Arabidopsis seedlings grown in Petri dishes sealed with PE plastic wrap, PP parafilm, or NF surgical tape showed differences in growth, with PE plastic wrap resulting in a smaller size and fresh weight, followed by PP parafilm, compared to unsealed or NF surgical tape-sealed dishes. To investigate the basis of these phenotypic changes, transcriptome sequencing was performed. The results indicated that seedlings in dishes sealed with PE plastic wrap and PP parafilm exhibited over 1000 differentially expressed genes (DEGs) at 7 days. By 14 days, the number of DEGs had increased to over 2000 for each sealed condition. GO analysis showed that DEGs were commonly enriched in biological processes associated with the response to hypoxia under PE plastic wrap and PP parafilm sealing at both 7 and 14 days, as well as under NF surgical tape at 14 days. While O₂ levels showed no significant differences between sealed and unsealed conditions, CO₂ concentrations were notably lower in plates sealed with PE plastic wrap and PP parafilm. Furthermore, specific genes related to reduced size and delayed growth under sealed conditions were identified. In summary, sealing films negatively affect seedling growth, leading to significant shifts in gene expression profiles. Full article

This study addresses the challenge of rapidly and accurately distinguishing zones of microbial activity from antibiotic inhibition zones in Petri dishes. We propose a laser speckle imaging technique enhanced with subpixel correlation analysis to monitor dynamic changes in the inhibition zone surrounding an antibiotic disc. This method provides faster results compared to the standard disk diffusion assay recommended by EUCAST. To enable automated analysis, we used machine learning algorithms for classifying areas of bacterial or fungal activity versus inhibited growth. Classification is performed over short time windows (e.g., 1 h), supporting near-real-time assessment. To further improve accuracy, we introduce a correction method based on the known spatial dynamics of inhibition zone formation. The novelty of the study lies in combining a speckle imaging subpixel correlation algorithm with ML classification and with pre- and post-processing. This approach enables early automated assessment of antimicrobial effects with potential applications in rapid drug susceptibility testing and microbiological research. Full article

The main aim of this research was to synthesize the new geopolymer composite and test its antibacterial properties. The new composites are based on a geopolymer matrix, with the addition of carbon fiber, nano-silica and antibacterial nanopowder. The first stage of this research was the synthesis of geopolymer composites containing variable proportions of nano-additives and, as a reference material, cement. The next step was bacterial cultivation. Two different bacterial strains were selected, Gram-positive and Gram-negative (Escherichia coli and Staphylococcus aureus). In this stage, the agar microbiological medium is used for the evaluation of bacterial growth inhibition by cement and geopolymers. In the final stage, the growth of the colony was observed and the pH measurements were taken. The final assessment of efficiency was made by using optical microscopy and a colony counter based on the Petri dish. The test performed showed that the main mineralogical components are quartz, 55.0%, and mullite, with 42.1% of crystalline ingredients. EDS analysis shows that the main oxide component is SiO₂, about 50.9%. The obtained results connected with bacteria growth show the growth of both types of bacteria on materials; however, after several days, the growth was inhibited. An assessment of microorganism growth inhibition by cement and geopolymers shows the better efficiency of geopolymer composites in this area for both types of colonies (Gram-positive and Gram-negative). The new element in this research was to plan the research from the point of view of its application in the water environment. The provided research can be useful for the inhibition of biofouling phenomena on marine and inland water infrastructure. Full article

This study evaluated the repellent activity of DEET, eugenol, methyl eugenol, 1,8-cineole, and their combinations against Amblyomma sculptum nymphs through laboratory and field tests. Initially, the botanical compounds were tested individually in Petri dish assays to assess repellent activity over various intervals (1 min to 168 h) at concentrations of 2%. Eugenol and methyl eugenol exhibited the highest average repellent percentages (60 to 90%), with significant effects (p < 0.05) across most evaluation periods, in contrast to 1,8-cineole. Therefore, eugenol and methyl eugenol were selected for combination testing with DEET. The combinations of 7% DEET + 1% eugenol and 7% DEET + 2% methyl eugenol showed the best results, with average repellent efficacy exceeding 85%. The first combination was selected for field evaluation. In this test, volunteers wore treated socks and walked for two hours in a naturally infested area. A significant reduction (p < 0.05) in the number of ticks recovered from the socks was observed in the 7% DEET and 7% DEET + 1% eugenol treatments, with efficacies of 82.5% and 88.5%, respectively, after 120 min. Isolated eugenol showed limited field efficacy, with significant repellent activity (p < 0.05) lasting only 20 min. The results highlight the potential of eugenol and methyl eugenol as repellent compounds, especially when combined with DEET. The field study confirmed the efficacy of the 7% DEET + 1% eugenol. Full article