-
Journal of Hazardous Materials Aug 2024Aspergillus niger (A. niger) spores can induce numerous health problems. Once the airflow-imposed drag force on an A. niger spore exceeds its binding force with the...
Aspergillus niger (A. niger) spores can induce numerous health problems. Once the airflow-imposed drag force on an A. niger spore exceeds its binding force with the colony, the spore is detached. Turbulent flow may considerably increase the spore detachment. No method is currently available for prediction of the drag force on a spore and its detachment in turbulent flows. This investigation measured the turbulent velocities and detachment of A. niger colonies in a wind tunnel. Computational fluid dynamics (CFD) was employed to model an A. niger unit subjected to turbulent flow blowing. The top 1 % quantile instantaneous velocity of the turbulent flow was specified as the steady entry flow boundary condition for solving the peak velocity distribution and the peak drag forces onto spores. The predicted spore detachment ratios were compared with the measurement data for model validation. The results revealed that the spore detachment ratios with a turbulence intensity of 17 % to 20 % can be twice to triple the ratio with a turbulence intensity of approximately 1 %, when the average velocity for blowing remains the same. The proposed CFD model can accurately predict the detachment ratios of the A. niger spores. ENVIRONMENTAL IMPLICATION: Some people are sensitive to the Aspergillus niger (A. niger) spores, and excessive exposure can cause nasal congestion, skin tingling, coughing, and even asthma. Turbulent flow can considerably increase the spore detachment, due to the increased airflow-imposed drag force on the spores during turbulence. This investigation developed a numerical model to solve for the peak velocity distribution and the peak drag forces onto spores in turbulent flows to predict the spore detachment. With the numerical tool, the airborne fungal spore concentrations would be predictable, which paves a way for intelligent and precise control of fungal aerosol pollution.
Topics: Aspergillus niger; Spores, Fungal; Air Microbiology; Models, Theoretical; Hydrodynamics; Air Movements
PubMed: 38889465
DOI: 10.1016/j.jhazmat.2024.134910 -
Microorganisms Jul 2023is a type of soil fungus with the ability to dissolve insoluble phosphate and secrete organic metabolites such as citric acid. However, whether cell-free fermentation...
is a type of soil fungus with the ability to dissolve insoluble phosphate and secrete organic metabolites such as citric acid. However, whether cell-free fermentation broth (AFB) promotes maize growth and alleviates low-phosphorus stress has not been reported. In this study, we explored their relationship through a hydroponics system. The results indicated that either too low or too high concentrations of AFB may inhibit seed germination potential and germination rate. Under low phosphorus conditions, all physiological indexes (biomass, soluble sugar content, root length, etc.) increased after AFB was applied. A qRT-PCR analysis revealed that the expression of the and genes, which are involved in root development, was upregulated, while the expression of the and genes, which are keys to the synthesis of antioxidant enzymes, was downregulated. The expression of , a key gene in lipid peroxidation, was down-regulated, consistent with changes in the corresponding enzyme activity. These results indicate that the application of AFB may alleviate the oxidative stress in maize seedlings, reduce the oxidative damage caused by low P stress, and enhance the resistance to low P stress in maize seedlings. In addition, it reveals the potential of to promote growth and provides new avenues for research on beneficial plant-fungal interactions.
PubMed: 37512909
DOI: 10.3390/microorganisms11071737 -
Pest Management Science Nov 2023Aspergillus niger is generally considered safe and is widely used across a broad range of industries from food to pharmaceuticals. The metabolites of some Aspergillus...
BACKGROUND
Aspergillus niger is generally considered safe and is widely used across a broad range of industries from food to pharmaceuticals. The metabolites of some Aspergillus species are effective in killing nematodes. The active ingredients that play a role are citric acid and oxalic acid.
RESULTS
The effective nematocidal metabolite in the fermentation broth of the A. niger Ym16 is a calcium oxalate coordination compound (C H O •2(C HO )•C O •4(H O)•2(Ca)). The mortality of fermentation broth and compound solution to second-stage juveniles (J2s) of Meloidogyne incognita were 94% (8 h) and 95% (2 h), respectively. The hatching inhibition rates of fermentation broth and compound solution to eggs of M. incognita were 86% (24 h) and 87% (12 h), respectively. Furthermore, the Ym16 strain promoted plant growth.
CONCLUSION
Strain Ym16 and its metabolites should be the first choice for nematode control because it is an effective agent against soil nematodes. © 2023 Society of Chemical Industry.
PubMed: 37440680
DOI: 10.1002/ps.7662 -
Artificial Cells, Nanomedicine, and... Dec 2023Emergent records propose that endophytic fungus is a vital source for various bioactive molecules possessing many biological properties. The current study was designed...
Emergent records propose that endophytic fungus is a vital source for various bioactive molecules possessing many biological properties. The current study was designed to inspect the antibacterial and anti-Toxoplasma potentials of -derived endophytic fungi. After isolation and identification (using 18S rRNA gene sequencing) of endophytic fungus, LC/MS was utilized for identification and authentication of the chemical profile of the endophyte extract. Then, the fungal extract was assessed for its antibacterial and antibiofilm activities against clinical isolates. Additionally, its efficacy against was elucidated . The fungal extract displayed antibacterial activity against isolates with minimum inhibitory concentration values of 64-512 µg/mL. It also possessed a membrane potential dissipating effect using flow cytometry. Moreover, it formed distorted cells with rough surfaces and deformed shapes using a scanning electron microscope (SEM). Regarding its antibiofilm activity, it resulted in a dysregulation of the genes encoding biofilm formation (H, A and D) using qRT-PCR in nine isolates. The anti-Toxoplasma potential was demonstrated by decreasing the mortality rate of mice and reducing the tachyzoites' count in the peritoneal fluids and liver impression smears of mice. In addition, the deformities of the parasite decreased, as revealed by SEM and the inflammation in tissues diminished. Thus, endophytic fungi could be a valuable source of antibacterial and anti-Toxoplasma compounds.
Topics: Aspergillus niger; Toxoplasma; Ficus; Anti-Bacterial Agents; Asteraceae; Plant Extracts
PubMed: 37224186
DOI: 10.1080/21691401.2023.2215531 -
Seminars in Respiratory and Critical... Feb 2024In the last decade, fungal respiratory diseases have been increasingly investigated for their impact on the clinical course of people with cystic fibrosis (CF), with a... (Review)
Review
In the last decade, fungal respiratory diseases have been increasingly investigated for their impact on the clinical course of people with cystic fibrosis (CF), with a particular focus on infections caused by spp. The most common organisms from this genus detected from respiratory cultures are and , followed by , , and . These species have been identified to be both chronic colonizers and sources of active infection and may negatively impact lung function in people with CF. This review article discusses definitions of aspergillosis, challenges in clinical practice, and current literature available for laboratory findings, clinical diagnosis, and treatment options for pulmonary diseases caused by spp. in people with CF.
Topics: Humans; Cystic Fibrosis; Pulmonary Aspergillosis; Aspergillosis; Aspergillus fumigatus
PubMed: 38286138
DOI: 10.1055/s-0043-1777267 -
PloS One 2024The purpose of current research work was to investigate the effect of mutagenesis on endoglucanase B activity of indigenous strain of Aspergillus niger and its...
The purpose of current research work was to investigate the effect of mutagenesis on endoglucanase B activity of indigenous strain of Aspergillus niger and its heterologous expression studies in the pET28a+ vector. The physical and chemical mutagens were employed to incorporate mutations in A. niger. For determination of mutations, mRNA was isolated followed by cDNA synthesis and cellulase gene was amplified, purified and sequenced both from native and mutant A. niger. On comparison of gene sequences, it was observed that 5 nucleotide base pairs have been replaced in the mutant cellulase. The mutant recombinant enzyme showed 4.5 times higher activity (428.5 µmol/mL/min) as compared to activity of native enzyme (94 µmol/mL/min). The mutant gene was further investigated using Phyre2 and I-Tesser tools which exhibited 71% structural homology with Endoglucanase B of Thermoascus aurantiacus. The root mean square deviation (RMSD), root mean square fluctuation (RMSF), solvent accessible surface area (SASA), radius of gyration (Rg) and hydrogen bonds analysis were carried at 35°C and 50°C to explore the integrity of structure of recombinant mutant endoglucanase B which corresponded to its optimal temperature. Hydrogen bonds analysis showed more stability of recombinant mutant endoglucanase B as compared to native enzyme. Both native and mutant endoglucanase B genes were expressed in pET 28a+ and purified with nickel affinity chromatography. Theoretical masses determined through ExPaSy Protparam were found 38.7 and 38.5 kDa for native and mutant enzymes, respectively. The optimal pH and temperature values for the mutant were 5.0 and 50°C while for native these were found 4.0 and 35°C, respectively. On reacting with carboxy methyl cellulose (CMC) as substrate, the mutant enzyme exhibited less Km (0.452 mg/mL) and more Vmax (50.25 µmol/ml/min) as compared to native having 0.534 mg/mL as Km and 38.76 µmol/ml/min as Vmax. Among metal ions, Mg2+ showed maximum inducing effect (200%) on cellulase activity at 50 mM concentration followed by Ca2+ (140%) at 100 mM concentration. Hence, expression of a recombinant mutant cellulase from A. niger significantly enhanced its cellulytic potential which could be employed for further industrial applications at pilot scale.
Topics: Aspergillus niger; Cellulase; Recombinant Proteins; Mutation; Enzyme Stability; Fungal Proteins; Temperature; Hydrogen-Ion Concentration
PubMed: 38748703
DOI: 10.1371/journal.pone.0298716 -
ACS Omega Jan 2024The goal behind this work is to prepare, characterize, and study the antimicrobial behavior of zirconia (ZrO) nanoparticles (NPs). Various techniques, such as X-ray...
The goal behind this work is to prepare, characterize, and study the antimicrobial behavior of zirconia (ZrO) nanoparticles (NPs). Various techniques, such as X-ray diffraction (XRD), were used for studying the mineralogical structure and crystal size. The microstructure and chemical composition of the prepared particles were analyzed using a scanning electron microscope attached with an energy-dispersive X-ray analysis (EDAX) unit. The antagonistic ability against several Gram-negative and Gram-positive bacteria, including , and , was assessed using the well diffusion method. The results of XRD and scanning electron microscopy (SEM) analyses revealed that the prepared material exhibited the phase of zirconium nanoparticles with particle sizes ranging between 40 and 75 nm. The antimicrobial test results demonstrated that the inhibitory effect increased with the increase of concentration. The inhibitory effect was more pronounced against Gram-positive bacteria, as indicated by the larger size of the inhibitory zone. At a 9% dimethyl sulfoxide (DMSO) concentration, the inhibitory zone had a diameter of 3.50 mm for compared to a diameter of 3.40 mm for . The use of zirconium oxide nanoparticles reduced the diameter of the inhibitory zone when tested against at a 3% DMSO concentration (0.50 mm diameter) and against (0.40 mm diameter). Zirconia nanoparticles were also evaluated for their antifungal activity against several species, including , , and sp. The size of the inhibitory zone indicated the susceptibility of microorganisms to nanozirconium oxide, resulting in a stronger inhibition of sp. at a 100% DMSO concentration (4.50 mm diameter) compared to and (3.00 mm diameter). The results for sp. at a 3% DMSO concentration showed a diameter of the inhibitory zone of 0.90 mm, while for and , the diameter was 0.80 mm. Thus, our findings demonstrate that the zirconium oxide nanoparticles possess the capability to reduce the inhibition zone effectively for both bacterial and fungal activities.
PubMed: 38250396
DOI: 10.1021/acsomega.3c08580 -
Chembiochem : a European Journal of... Nov 2023Psilocybe "magic mushrooms" are chemically well understood for their psychotropic tryptamines. However, the diversity of their other specialized metabolites, in...
Psilocybe "magic mushrooms" are chemically well understood for their psychotropic tryptamines. However, the diversity of their other specialized metabolites, in particular terpenoids, has largely remained an open question. Yet, knowledge on the natural product background is critical to understand if other compounds modulate the psychotropic pharmacological effects. CubA, the single clade II sesquiterpene synthase of P. cubensis, was heterologously produced in Escherichia coli and characterized in vitro, complemented by in vivo product formation assays in Aspergillus niger as a heterologous host. Extensive GC-MS analyses proved a function as multi-product synthase and, depending on the reaction conditions, cubebol, β-copaene, δ-cadinene, and germacrene D were detected as the major products of CubA. In addition, mature P. cubensis carpophores were analysed chromatographically which led to the detection of β-copaene and δ-cadinene. Enzymes closely related to CubA are encoded in the genomes of various Psilocybe species. Therefore, our results provide insight into the metabolic capacity of the entire genus.
Topics: Psilocybe; Sesquiterpenes; Alkyl and Aryl Transferases
PubMed: 37614035
DOI: 10.1002/cbic.202300511 -
Journal of Microbiology and... Feb 2024Corn cobs were fermented with to produce soluble dietary fiber (SDF) of high quality and excellent food safety. In this work, the fermentation process was optimized by...
Corn cobs were fermented with to produce soluble dietary fiber (SDF) of high quality and excellent food safety. In this work, the fermentation process was optimized by single-factor test and response surface methodology (RSM). The optimal fermentation conditions were determined to be a material-liquid ratio of 1:30, an inoculum concentration of 11%, a temperature of 32°C, a time of 6 days, and a shaking speed of 200 r/min. Under these conditions, the SDF yield of corn cob increased from 2.34% to 11.92%, and the ratio of soluble dietary fiber to total dietary fiber (SDF/TDF) reached 19.08%, meeting the requirements for high-quality dietary fiber (SDF/TDF of more than 10%). Scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FT-IR) analysis revealed that the fermentation effectively degraded part of cellulose and hemicellulose, resulting in the formation of a loose and porous structure. After fermentation the water swelling capacity, water-holding capacity, and oil-holding capacity of the corn cob SDF were significantly improved and the adsorption capacity of glucose, cholesterol, and nitrite ions all increased by more than 20%. Moreover, the total phenolic content increased by 20.96%, which correlated with the higher antioxidant activity of SDF. Overall, the fermentation of corn cobs by increased the yield and enhanced the functional properties of dietary fiber (DF) as well.
Topics: Aspergillus niger; Zea mays; Spectroscopy, Fourier Transform Infrared; Dietary Fiber; Water
PubMed: 38073331
DOI: 10.4014/jmb.2308.08010 -
3 Biotech Jul 2024Lipase has high economic importance and is widely used in biodiesel, food, detergents, cosmetics, and pharmaceutical industries. The rapid development of synthetic... (Review)
Review
Lipase has high economic importance and is widely used in biodiesel, food, detergents, cosmetics, and pharmaceutical industries. The rapid development of synthetic biology and system biology has not only paved the way for comprehensively understanding the efficient operation mechanism of cell factories but also introduced a new technological system for creating and optimizing high-efficiency cell factories. In this review, all relevant data on microbial lipase enzyme sources and general properties are gathered and updated. The relationship between strain morphology and protein production is discussed. The safety of strain is investigated to ensure product safety. The biotechnologies and factors influencing lipase expression in are summarized. This review focuses on various strategies to improve lipase expression in . The summary of these methods and the application of the gene editing technology CRISPR/Cas9 system can further improve the efficiency of constructing the engineered lipase-producing .
PubMed: 38841267
DOI: 10.1007/s13205-024-03998-5