Aspergillus Niger Strain Research Articles

Synthesis, Spectroscopy and Biological Studies of Copper and Silver Complexes Derived from 2-Substituted Amino Propanoic Acid

Synthesis of copper and silver complexes were prepared from novel Schiff base ligand. These synthesized ligand and their metal complexes were characterized by elemental analysis, FT-IR, 1H NMR, UV-Vis and Mass spectrometry. The coordination of amino nitrogen, phenolic oxygen, and carboxylato oxygen atoms is shown by the infrared spectra.The Schiff bases and its complexes were screened for their in vitro antibacterial and antifungal studies against the bacteria Pseudomonas Aeruginosa (PA, Gram -ve), Bacillus Cirroflagellosus (BC, Gram +ve), Penicillium Notatium (PN) and Aspergillus Niger (AN) strains. The results of the antibacterial investigation show that the copper and silver complexes possess more potent bactericide and fungicide properties than the ligand.

Oxygen Consumption in Filamentous Pellets of Aspergillus niger: Microelectrode Measurements and Modeling.

Filamentous fungi cultivated as biopellets are well established in biotechnology industries. A distinctive feature of filamentous fungi is that hyphal growth and fungal morphology affect product titers and require tailored process conditions. Within the pellet, mass transfer, substrate consumption, and biomass formation are intricately linked to the local hyphal fraction and pellet size. This study combined oxygen concentration measurements with microelectrode profiling and three-dimensional X-ray microtomography measurements of the same fungal pellets for the first time. This allowed for the precise correlation of micromorphological information with local oxygen concentrations of two Aspergillus niger strains (hyperbranching and regular branching). The generated results showed that the identified oxygen-penetrated outer pellet regions exhibited a depth of 90-290 µm, strain-specific, with the active part percentage in the pellet ranging from 18% to 69%, without any difference between strains. Using a 1D continuum diffusion consumption model, the oxygen concentration in the pellets was computed depending on the local hyphal fraction. The best simulation results were achieved by individually estimating the oxygen-related biomass yield coefficient of the consumption term within each examined pellet, with an average estimated value of 1.95 (± 0.72) kg biomass per kg oxygen. The study lays the foundation for understanding oxygen supply in fungal pellets and optimizing processes and pellet morphologies accordingly.

Safety evaluation of the food enzyme glucan-1,4-α-glucosidase from the non-genetically modified Aspergillus niger strain DP-Azh100.

The food enzyme glucan-1,4-α-glucosidase (4-α-d-glucan glucohydrolase; EC 3.2.1.3) is produced with the non-genetically modified Aspergillus niger strain DP-Azh100 by Genencor International B.V. It was considered free from viable cells of the production organism. The food enzyme is intended to be used in four food manufacturing processes. Since residual amounts of total organic solids (TOS) are removed in two processes, dietary exposure was calculated only for the two remaining processes. It was estimated to be up to 1.390 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose tested of 1000 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 719. A search for the homology of the amino acid sequence of the food enzyme to known allergens was made and one match to a respiratory allergen was found. Known sources of food allergens were used in the food enzyme manufacturing process. The Panel considered that the risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Isolation and Molecular Identification of Fungal Contamination on the Eggshells of Lepidochelys olivacea L. Collected from Coastal Waters

Background: One of the causes of the decline in the Olive ridley turtle population is the low egg hatching rate due to contamination by pathogenic fungi. Purpose: This study aims to evaluate the results of the isolation and molecular identification of fungal contamination on the eggshells of olive ridley turtles that failed to hatch from three coastal waters in Bali province. Method: Sampling was done using the purposive sampling technique. Samples of failed hatching eggshells from the coast were collected, as many as 2 eggs/semi-natural nest at TCEC. Samples were cultured on PDA media. Macroscopic and molecular identification methods were carried out to determine the species level of fungal isolates. Results: The results showed that 10 fungal isolates were successfully collected. Isolates KL1 and SG1 had white colony surface characteristics, isolates KL4, SY2 and SY3 showed black colonies, and isolates KL2, KL3, SG2, SG3, SY4 had green colonies. Three similar isolates were sent for further molecular identification. The BLASTn results of the nucleotide sequences of isolates SY2 and SG3 showed a similarity to Aspergillus niger strain PHY105 (91%), while fungal isolate KL1 had a similarity to Fusarium solani strain 87, by 98%. Conclusion: This study provides new information about the pathogenic fungi, Fusarium solani strain 87 and Aspergillus niger strain PHY105, which are suspected to be the cause of the hatching failure of olive ridley turtle eggs.

Antimicrobial Activity of Honey and Propolis from Alba County, Romania.

Investigating the quality of bee products obtained across different geographical regions and analyzing their antimicrobial activity is of significant interest to various scientific disciplines. This study focuses on comparing the antimicrobial activity of honey and propolis samples from different areas of Alba County, Romania. The quality parameters of five samples of two types of bee products (honey and propolis) were assessed. Then, the samples were tested to comparatively determine their antimicrobial properties against 12 species of bacteria (Escherichia coli, Salmonella typhimurium, Salmonella enteritidis, Salmonella anatum, Salmonella choleraesuis, Pseudomonas aeruginosa, Pseudomonas fluorescens, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis, and Listeria monocytogenes) and 7 fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, Rhizopus stolonifer, Fusarium oxysporum, and Alternaria alternata). Of the bacterial strains, the most sensitive to the action of honey samples were the two strains of Staphylococcus followed by P. fluorescens. The two strains of Pseudomonas and L. monocytogenes were the most sensitive to the activity of propolis. Of the fungal strains, F. oxysporum was the most sensitive to the actions of both honey and propolis, followed by P. chrysogenum in the case of honey samples and the two Aspergillus strains in the case of propolis. These findings indicate that bee products are rich sources of bioactive compounds exhibiting strong antimicrobial properties and significant potential for the development of new phytopharmaceutical products.

Green-synthesized carbon dots from ginger: Multifunctional agents against oral pathogens with biocompatibility in human gingival fibroblast cells

Persistent antibiotic use in treating oral infections often leads to drug resistance in pathogenic bacteria, notably impacting conditions like periodontitis. Addressing this challenge, the study pioneers the use of carbon dots (CDs) synthesized from ginger rhizomes (Zingiber officinale) as a novel biocompatible material. CDs were synthesized via the hydrothermal method, emphasizing a green approach, and comprehensively characterized for their optical properties and structural uniformity. The synthesized CDs showed a zeta potential of −24.9 mV, confirming the formation of stable and well-dispersed particles. Dynamic Light Scattering (DLS) confirmed an average particle size of 2.9 nm, thus validating the formation of CDs. Biomedical assessments demonstrated that the synthesized CDs were non-cytotoxic to human gingival fibroblast cell lines, with effective free radical scavenging activity and high total antioxidant capacity, as indicated by their IC50 values. CDs also exhibited moderate inhibition of protein denaturation compared to the standard. Moreover, they showed significant inhibitory effects against bacterial strains (Pseudomonas aeruginosa, Lactobacillus acidophilus, Escherichia coli, Staphylococcus aureus) and fungal strains (Aspergillus niger, Candida albicans) at minimal concentrations. Notably, CDs inhibited the growth of periodontal pathogens including Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis, and Prevotella intermedia. These findings underscore the potential of CDs as multifunctional agents possessing anti-inflammatory, antifungal, antioxidant, and antibacterial properties. Remarkably, they offer a promising alternative to conventional antibiotics, potentially revolutionizing oral healthcare. Their proven biocompatibility and potent bioactivity underscore their innovative potential in biomedical research. Future studies should further assess their efficacy in vivo to fully harness their clinical potential.

Phyto-mediated biosynthesis of silver nanoparticles using Aloe barbadensis Miller leaves gel with improved antibacterial, anti-fungal, antioxidant, anti-inflammatory, anti-diabetic, and anti-cancer activities

An effective topical therapeutic agent requires a multifunctional attribute such as antibacterial, antioxidant, and anti-inflammatory efficacy. The green-synthesized metallic and metallic oxide nanoparticles have shown significant applicability in this regard. Hence a biosynthesis of silver nanoparticles (AgNPs) using Aloe barbadensis miller leaf gel was fabricated and evaluated for effect of imperative influences such as temperature, time, and concentration of reactant on AgNPs synthesis. Furthermore, the biomimetic qualities were assessed to ensure the safety and efficacy. The synthesis of stabilized and capped AgNPs presented a UV–vis–based plasmonic resonance at ∼ 400 nm. The reduction of silver nitrate was further confirmed by the shift in FTIR spectra for -OH around 2870 cm−1. SEM and TEM images revealed cubic shape of the AgNPs. Whereas X-ray diffraction pattern indicated crystalline structure (crystallite size of ∼ 31.14 nm) with an inter-planar spacing value of 2.77, 1.96, and 1.67 Å for (200), (220), and (311) planes, respectively. In addition, AgNPs indicated a steady dispersion, homogeneity, and strong anionic zeta potential (∼ 35.4 mV). The results of antibacterial and antifungal activity demonstrated the potential of phyto-synthesized AgNPs in mitigation of infection associated with tested bacterial strain Bacillus subtilis, Bacillus megaterium, Shigella flexneri, Trichoderma viride, Aspergillus niger, and Penicillium crysogenum. Moreover, the results of hydrogen peroxide-based scavenging, anti-inflammatory, and anti-diabetic study revealed that the biosynthesized AgNPs exhibit an improved biomimetic attribute. Additionally, the biocompatibility assay demonstrated > 80 % of CaCO-2 and L-929 cells viability at 1.67 μg/mL and 3.35 μg/mL, respectively. The anticancer activity of synthesized AgNPs against epithelium-like phenotype oral squamous carcinoma cells (CLS-354/WT) displayed IC50 of 11.58 μg/mL. The results indicate that biogenic produced AgNPs may find suitable use as a potential therapeutic agent due to multifunctional attribute.

Isolation and identification of endophytic fungi from Alhagi sparsifolia Shap. and their antibacterial activity

In order to explore the endophytic resources of Alhagi sparsifolia Shap. and identified novel antibacterial substances. Thirty endophytic fungal strains were isolated from the stems and roots of A. sparsifolia Shap. Morphological and molecular biology methods were used to identify ten strains of fungi, including four strains of Aspergillus niger, three strains of Alternaria alternata, two strains of Aspergillus flavus, and one strain of Fusarium incarnatum. All these strains were isolated from A. sparsifolia Shap. for the first time, and of these Aspergillus was the dominant genus. Antibacterial activity of the ten strains against Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa were evaluated using the disc diffusion method. The results demonstrated that the metabolites from all the strains had inhibitory effects on at least one indicator bacterium. Notably, the endophytic fungi AFJ3 and AFG6 demonstrated strong broad-spectrum antibacterial activity, particularly against E. coli, with inhibition zones measuring 32.0 ± 0.3 and 31.3 ± 0.3 mm, respectively. The three endophytic fungi (AFG1, AFG2, and AFG3) isolated from the roots demonstrated significant antibacterial activity against P. aeruginosa forming an inhibition zone of diameter 31.3 ± 0.1, 25.6 ± 0.2, and 25.6 ± 0.2 mm, respectively. However, the strains of endophytic fungi demonstrated no significant inhibitory effects on C. albicans. Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry/mass spectrometry (UPLC-QTOF-MS/MS) analysis depicted that the ethyl acetate phase of AFJ3 and AFG6 fermentation broth predominantly contained organic acids, phenolic acids, flavonoids, and fatty acids. These secondary metabolites often exhibited good antibacterial activity. This study broadens our understanding of endophytic fungi in A. sparsifolia Shap. The antibacterial activity of some strains of endophytic fungi was significant, making it worthy of further research on their active material.

Safety evaluation of the food enzyme carboxypeptidase C from the genetically modified Aspergillus niger strain PEG.

The food enzyme carboxypeptidase C (EC 3.4.16.5) is produced with the genetically modified Aspergillus niger strain PEG by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in nine food manufacturing processes. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 2.053 mg TOS/kg body weight (bw) per day in European populations. The toxicity studies were carried out with a xylanase obtained from A. niger strain XEA. The Panel considered this food enzyme as a suitable substitute for the carboxypeptidase to be used in the toxicological studies, because both strains were derived from the same recipient strain, the location of the inserts was comparable, no partial inserts were present and the production methods were essentially the same. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1850 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 901. A homology search for the amino acid sequence of the food enzyme to known allergens was made and one match with a wheat allergen was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, especially in wheat-allergic individuals, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of an extension of use of a food enzyme containing endo-polygalacturonase, pectinesterase, pectin lyase and non-reducing end α-l-arabinofuranosidase activities from the non-genetically modified Aspergillus niger strain PEC.

The food enzyme has four declared activities: endo-polygalacturonase ((1-4)-α-d-galacturonan glycanohydrolase (endo-cleaving); EC 3.2.1.15), pectinesterase (pectin pectylhydrolase; EC 3.1.1.11), pectin lyase ((1-4)-6-O-methyl-α-d-galacturonan lyase; EC 4.2.2.10) and non-reducing end α-l-arabinofuranosidase (α-l-arabinofuranoside non-reducing end α-l-arabinofuranosidase; EC 3.2.1.55). It is produced with the non-genetically modified Aspergillus niger strain PEC by DSM Food Specialties B.V. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in three food manufacturing processes. Subsequently, the applicant has requested to extend its use to include four additional processes. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of seven food manufacturing processes. As the food enzyme-total organic solids (TOS) are removed from the final foods in one food manufacturing process, the dietary exposure to the food enzyme-TOS was estimated only for the remaining six processes. The dietary exposure was calculated to be up to 0.612 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (204 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 333. Based on the previous evaluation, the assessment of the new data and the revised margin of exposure, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Assessment of Fungal Contamination and Their Toxigenic Potential of Farmed Fish in Western Algeria

Fish and fish products have been documented as a major source of pathogens, with fungi playing a key role. In this paper, a survey was conducted to determine the presence of fungi in fish reared in various aquaculture farms in western Algeria, namely Nile Tilapia (Oreochromis niloticus), gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). The search for micromycetes was carried out on different parts of the body: skin and flesh, gills, and intestines. A total of 1937 fungal strains were revealed and divided into 10 genera of filamentous fungi, one genus of yeast, and other yeasts that have not yet been determined. Penicillium was the most common genus, representing 41.56% of the fungal population, fol-lowed by Rhodotorula (17.60%), and Aspergillus (15.95%). The greatest number of isolates was identified in the gills of gilthead sea bream, while the lowest number was isolated from sea bass intestines. Secondly, we sought to highlight the toxigenic potential of the fungal strains isolated, using the brine shrimp lethality test. Five of the fungal strains tested, belonging to the two genera Penicillium and Aspergillus, showed toxic potential for Artemia salina. The highest toxicities were observed mainly by strains of Aspergillus parasiticus (APAR001), Aspergillus terreus (ATER002), and Aspergillus niger (ANIG001) respectively. Penicillium chrysogenum (PCHR002) showed the lowest activity. These results confirm the infection of farmed fish by toxigenic fungal communities, which can present a real health hazard to consumers. Regular monitoring and compliance with fish health management practices are recommended.

Antimicrobial and Computational Studies of Newly Synthesized Benzotriazoles.

Antimicrobial Resistance (AMR) due to non-responding viruses, fungi, bacteria and parasites leads to discovery of new antimicrobial medicines which can control the risk of disease spread, severe illness, disability and death. Heterocyclic chemistry has always been a continuous supplier of novel antimicrobial agents which are in great demand in pharma sector. Therefore, compounds such as 1-(Chloromethyl)-1H-Benzotriazole, 1; 1-((1-H-benzo[d][1,2,3]triazol-1-yl)methyl)phenyl hydrazine, 2; 1-((1-H-benzo[d][1,2,3]triazol-1-yl)methyl)hydrazine, 3; and N-(benzo[e][1,2,4]triazin-4(3-H)-ylmethylbenzenamine, 4 were designed, and synthesized through conventional and microwave-assisted methods. All of these novel benzotriazoles were explored through in-vitro antimicrobial studies and in silico studies. Antimicrobial activity was carried out against bacterial strains Escherichia coli, Bacillus subtilis, and fungal strains Aspergillus niger and Candida albicans at concentrations 5, 10 and 15mg/ml. In silico studies was carried out with 4CAW: Aspergillus fumigatus N-myristoyl transferase in complex with myristoyl CoA and a pyrazole sulphonamide ligand. Our antimicrobial and molecular docking studies revealed that all of the derivatives showed promising activity, moreover molecular docking gave significant values of ligand posed energy and docking run elapsed time which further endorsed the astonishing characteristic of benzotriazole derivatives esp. N-(benzo[e]a[1,2,4] triazin-4(3-H)-ylmethylbenzenamine for biological and therapeutic leads.

Role of Copper Ions in Resistance of Modern Polymer Composite Materials to Fungal Damage

Resistance of polymer composite materials to biodamage is one of the pressing problems of our time. Incorporation of Cu2O (I) in the composition of a polymer composite based on the ED-20 epoxy resin increases its biocidal properties. Under conditions of mineral and organic contamination, the area of the samples affected by micromycetes was found to decrease with increasing concentration of dispersed particles in the composite. The affected area of the samples filled with the particles encapsulated in polylactide was 1.5 times smaller than that of the composites filled with non-encapsulated particles. Сopper oxide had a toxic effect on the Aspergillus niger strain dominant on the surface of the samples, causing a decrease in the average radial growth rate on the Czapek-Dox agar medium and in the biomass weight concentration during the growth of micromycetes in a liquid medium compared to the variant without Cu2O.

Evaluation of the antibacterial and antifungal properties of oleuropein, olea Europea leaf extract, and thymus vulgaris oil

BackgroundAlthough synthetic preservatives and antioxidants may have high antimicrobial and antioxidant activity, they are usually associated with adverse effects on human health. Currently, there is a growing interest in natural antimicrobial and antioxidant agents. This study aimed to evaluate the antimicrobial activity of two medicinal plant extracts and one active compound. Olive leaf extracts (0.2, 0.3, and 0.4% w/v), oleuropein (0.2, 0.4, and 0.6% w/v), thyme oil (0.1%), and oleuropein in combination with thyme oil (0.4% w/v and 0.1% v/v) were used against three bacterial strains (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Aspergillus niger).ResultsThe use of oleuropein resulted in complete antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In this context, a reduction of 7 logs was achieved during the storage period (4 weeks). Oleuropein showed no fungal activity at low concentrations (0.2%), but Aspergillus niger was reduced by 2.35 logs at higher concentrations (0.6% w/v). Similar antibacterial and antifungal properties were observed for the olive leaf extracts. Oleuropein at a concentration of 0.4 w/v and a mixture of oleuropein and thyme at concentrations of 0.4 and 0.1 (v/v) showed strong antimicrobial activity against the studied microorganisms.ConclusionOlive leaf extract, thyme oil, and oleuropein have strong antibacterial and weak antifungal properties. There was a good synergistic effect between oleuropein and thymol.

Fungal Peptidomelanin: A Novel Biopolymer for the Chelation of Heavy Metals.

Melanin is an amorphous, highly heterogeneous polymer found across all kingdoms of life. Although the properties of melanin can greatly vary, most forms are insoluble and strongly absorb light, appearing dark brown to black. Here, we describe a water-soluble form of melanin (peptidomelanin) secreted by the spores of Aspergillus niger (strain: melanoliber) during germination. Peptidomelanin is composed of an insoluble L-DOPA core polymer that is solubilized via short, copolymerized heterogeneous peptide chains forming a "corona" with a mean amino acid length of 2.6 ± 2.3. Based on in vitro experiments, we propose a biochemical copolymerization mechanism involving the hydroxylation of tyrosynylated peptides. Peptidomelanin is capable of chelating heavy metals such as lead, mercury, and uranium (as uranyl) in large quantities. Preliminary data indicates that peptidomelanin may have applications for the remediation of heavy metals in situ, including in agricultural settings.

Exploring the aroma profile and biomedical applications of Scutellaria nuristanica Rech. F.: A new insight as a natural remedy

BackgroundThe Scutellaria genus has promising therapeutic capabilities as an aromatherapy. Based on that and local practices of S. nuristanica Rech. F. The essential oil was studied for the first time for its diverse biomedical applications. PurposeThis study aimed to evaluate and validate their therapeutic capabilities by screening the essential oil ingredients and examining their antimicrobial, antioxidant, carbonic anhydrase, and antidiabetic using further In silico assessment and In vivo anti-inflammatory and analgesic capabilities to devise novel sources as natural remedies alternative to the synthetic drugs. MethodsEssential oil was obtained through hydrodistillation, and the constituents were profiled using GC–MS. The antimicrobial assessment was conducted using an agar well diffusion assay. Free radical scavenging capabilities were determined by employing DPPH and ABTS assay. The carbonic anhydrase-II was examined using colorimetric assay, while the antidiabetic significance was performed using α-Glucosidase assay. The anti-inflammatory significance was examined through carrageenan-induced paw edema, and the analgesic features of the essential oil were determined using an acetic acid-induced writhing assay. ResultsFifty constituents were detected in S. nuristanica essential oil (SNEO), contributing 95.93 % of the total EO, with the predominant constituents being 24-norursa-3,12-diene (10.12 %), 3-oxomanoyl oxide (9.94 %), methyl 7-abieten-18-oate (8.85 %). SNEO presented significance resistance against the Gram-positive bacterial strains (GPBSs), Bacillus atrophaeus and Bacillus subtilis, as compared to the Salmonella typhi and Klebsiella pneumoniae, Gram-negative bacterial strains (GNBSs) as well as two fungal strains Aspergillus parasiticus and Aspergillus niger associated with their respective standards. Considerable free radical scavenging capacity was observed in DPPH compared to the ABTS assay when correlated with ascorbic acid. In addition, when equated with their standards, SNEO offered considerable in vitro carbonic anhydrase II and antidiabetic capabilities. Additionally, the antidiabetic behavior of the 9 dominant compounds of SNEO was tested via In silico techniques, such as molecular docking, which assisted in the assessment of the significance of binding contacts of protein with each chemical compound and pharmacokinetic evaluations to examine the drug-like characteristics. Molecular dynamic simulations at 100 ns and binding free energy evaluations such as PBSA and GBSA models explain the molecular mechanics and stability of molecular complexes. It was also observed that SNEO depicted substantial anti-inflammatory and analgesic capabilities. ConclusionHence, it was concluded that the SNEO comprises bioactive ingredients with biomedical significance, such as anti-microbial, antioxidant, CA-II, antidiabetic, anti-inflammatory, and analgesic agents. The computational validation also depicted that SNEO could be a potent source for the discovery of anti-diabetic drugs.

Comparison of enhanced neural network and response surface models in predicting bio-dissolution of aluminum and vanadium from bauxite residue by isolated Aspergillus niger strains

Background: Recovery of Al and V from red mud, a hazardous residue of the Bayer process, using bioleaching is a nature-based waste management solution that simultaneously improves environment protection and metallurgical recoveries.Methods: For the first time, a novel hybrid multilayer Perceptron (MLP) network enhanced by an Imperialist Competitive Algorithm (ICA), and a response surface developed based on a factorial experiment design methodology (RSM) were employed and compared for, prediction optimization and optimization prediction of Al and V bioleaching by strains of A. Niger microorganisms isolated from pistachio shells and grape skins. The controlling variables were fungi source (A), adoption strategy (B), solid activation (C), solid percent (D), and bioleaching time. Considering the stochastic nature of ICA, a multi-criteria-ranking system based on accuracy and error indices was developed to select the best MLP. Probability value at 95% confidence interval, lack-of-fit, analysis of variance, R2, Adj. R2, and predicted R2 were the judges for the determination of the developed model's statistical significance.Significant Findings: Based on ANOVA, between A, B, C, and D, the effectiveness orders of A > D > C>AC>AD on Al, and A>AD>C>AC>D on V bioleaching were obtained. The superiority of the developed hybrid ICA-MLP model over the developed RSM model in predicting Al and V dissolution was determined by NSE, RSME, MAE, and MEDAE. Parameters optimization and consequently evaluating optimum condition repeatability through three repeating experiments resulted in maximum dissolution recoveries of RSM: 96.5% for Al and 91.2% for V, and ICA-MLP: 97.1% for Al and 90.3% for V. Considering the lower relative errors of repeating validation tests, it can be concluded that, although both models provide reasonable results, but the ICA-MLP methodology is more reliable (relative error <1.8%).

Mitigating the detrimental impacts of low- and high-density polyethylene microplastics using a novel microbial consortium on a soil-plant system: Insights and interactions

The accumulation of polyethylene microplastics (PE-MPs) in soil has raised considerable concerns; however, the effects of their persistence and mitigation on agroecosystems have not been explored. This study aimed to assess the detrimental effects of PE-MPs on a soil-plant system and evaluate their mitigation using a novel microbial consortium (MC). We incorporated low-density polyethylene (LDPE) and high-density polyethylene (HDPE) at two different concentrations, along with a control (0 %, 1 %, and 2 % w/w) into the sandy loam soil for a duration of 135 days. The samples were also treated with a novel MC and incubated for 135 days. The MC comprised three bacterial strains (Ralstonia pickettii (MW290933) strain SHAn2, Pseudomonas putida strain ShA, and Lysinibacillus xylanilyticus XDB9 (T) strain S7–10F), and a fungal strain (Aspergillus niger strain F1–16S). Sunflowers were subsequently cultivated, and physiological growth parameters were measured. The results showed that adding 2 % LDPE significantly decreased soil pH by 1.06 units compared to the control. Moreover, adding 2 % HDPE resulted in a more significant decrease in soil electrical conductivity (EC) relative to LDPE and the control. A dose-dependent increase in dissolved organic carbon (DOC) was observed, with the highest DOC found in 2 % LDPE. The addition of higher dosages of LDPE reduced soil bulk density (BD) more than HDPE. The addition of 2 % HDPE increased the water drop penetration time (WDPT) but decreased the mean weight diameter of soil aggregates (MWD) and water-stable aggregates (WSA) compared to LDPE. The results also revealed that higher levels of LDPE enhanced soil basal respiration (BR) and microbial carbon biomass (MBC). The interaction of MC and higher MP percentages considerably reduced soil pH, EC, BD, and WDPT but significantly increased soil DOC, MWD, WSA, BR, and MBC. Regarding plant growth, incorporating 2 % PE-MPs significantly reduced physiological responses of sunflower: chlorophyll content (Chl; −15.2 %), Fv/Fm ratio (-25.3 %), shoot dry weight (ShD; −31.3 %), root dry weight (RD; −40 %), leaf area (LA; −38.4 %), and stem diameter (StemD; −25 %) compared to the control; however, the addition of novel MC considerably reduced and ameliorated the harmful effects of 2 % PE-MPs on the investigated plant growth responses.

Safety evaluation of the food enzyme asparaginase from the genetically modified Aspergillus niger strain ASP.

The food enzyme asparaginase (l-asparagine amidohydrolase; EC 3.5.1.1) is produced with the genetically modified Aspergillus niger strain ASP by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in the prevention of acrylamide formation in foods and in the processing of yeast and yeast products. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.792 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose tested of 1038 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 1311. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme 3-phytase from the non-genetically modified Aspergillus niger strain PHY93-08.

The food enzyme 3-phytase (myo-inositol-hexakisphosphate 3-phosphohydrolase EC 3.1.3.8) is produced with the non-genetically modified Aspergillus niger strain PHY93-08 by Shin Nihon Chemical Co., Ltd. The food enzyme is free from viable cells of the production organism. It is intended to be used in nine food manufacturing processes. Since residual amounts of food enzyme-total organic solids (TOS) are removed in two of the food manufacturing processes, dietary exposure was calculated only for the remaining seven processes. It was estimated to be up to 0.763 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise safety concerns. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2560 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 3355. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no matches were found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.