scholarly journals Impact of inorganic powder additives on the size and morphology of pellets of the microscopic filamentous fungus Aspergillus niger

2021 ◽  
Vol 20 (1) ◽  
pp. e819
Author(s):  
Sanja Nosalj ◽  
Alexandra Šimonovičová ◽  
Karol Jesenák ◽  
Pavol Hudec

This paper has been focused on the impact of the set of microcrystal water-insoluble inorganic additives to dimension characteristics of pellets of the microscopic filamentous fungus Aspergillus niger. The selection of powder substances included montmorillonite clay mineral, silicon dioxide, iron oxide, one zeolitic tuff with mineral clinoptilolite as its main component, three synthetic zeolites, Na-mordenite, NaY and Na-ZSM-5, and titanium dioxide. This group is comprised of substances that are often components of various natural waters (including contaminated waters) and also frequent components of soil. Exceptions are synthetic zeolites and titanium dioxide. The impact of aforementioned substances was monitored on four Aspergillus niger strains isolated from soils at four Slovak locations, markedly differing in soil reaction values. Three of these soil samples have been affected by considerable contamination due to previous mining activities. Clay mineral montmorillonite reduced the size of the pellets regardless of the origin of strains, while the impact of other inorganic substances was either weak or variable depending on the type of inorganic substance and source location of the strains. The impact of natural zeolitic tuff was also similar, however, less significant.

2020 ◽  
Vol 76 (3) ◽  
pp. 62-70
Author(s):  
Konstantin Razmakhnin ◽  
Vitaliy Vitalievich Milyutin ◽  
Alisa Nikolaevna Khatkova ◽  
Nataliya Anatolevna Nekrasova

The possibilities of conditioning acidified wastewater from mining enterprises by natural zeolites of deposits in East Transbaikalia were studied. Sorption characteristics of various natural and synthetic zeolites in relation to strontium and cesium radionuclides were determined to evaluate the possibility of their application for the purification of radioactively contaminated technogenic and natural waters. The ability of natural zeolites to selectively adsorb the heavy metal ions was investigated. An experimental study was made on the possibility of neutralizing acidic media with zeolites. The kinetic dependencies were obtained to evaluate the ion exchange rate on the natural zeolites. The impact of exchanging cations and the defining mineral’s structure on the exchange rate was studied. The instantaneous adsorption interaction rate values were determined. The possibility of 90Sr and Ca2+ ions sorption from the simulated solutions of industrial wastewater was investigated.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Fatma Y. Ahmed ◽  
Usama Farghaly Aly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Nancy G. F. M. Waly

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.


2021 ◽  
Vol 22 (2) ◽  
pp. 772
Author(s):  
Javier Conde ◽  
Marlene Schwarzfischer ◽  
Egle Katkeviciute ◽  
Janine Häfliger ◽  
Anna Niechcial ◽  
...  

Environmental and genetic factors have been demonstrated to contribute to the development of inflammatory bowel disease (IBD). Recent studies suggested that the food additive; titanium dioxide (TiO2) might play a causative role in the disease. Therefore, in the present study we aimed to explore the interaction between the food additive TiO2 and the well-characterized IBD risk gene protein tyrosine phosphatase non-receptor type 2 (Ptpn2) and their role in the development of intestinal inflammation. Dextran sodium sulphate (DSS)-induced acute colitis was performed in mice lacking the expression of Ptpn2 in myeloid cells (Ptpn2LysMCre) or their wild type littermates (Ptpn2fl/fl) and exposed to the microparticle TiO2. The impact of Ptpn2 on TiO2 signalling pathways and TiO2-induced IL-1β and IL-10 levels were studied using bone marrow-derived macrophages (BMDMs). Ptpn2LysMCre exposed to TiO2 exhibited more severe intestinal inflammation than their wild type counterparts. This effect was likely due to the impact of TiO2 on the differentiation of intestinal macrophages, suppressing the number of anti-inflammatory macrophages in Ptpn2 deficient mice. Moreover, we also found that TiO2 was able to induce the secretion of IL-1β via mitogen-activated proteins kinases (MAPKs) and to repress the expression of IL-10 in bone marrow-derived macrophages via MAPK-independent pathways. This is the first evidence of the cooperation between the genetic risk factor Ptpn2 and the environmental factor TiO2 in the regulation of intestinal inflammation. The results presented here suggest that the ingestion of certain industrial compounds should be taken into account, especially in individuals with increased genetic risk


2017 ◽  
Vol 18 (3) ◽  
pp. 968-975
Author(s):  
R. G. Silva ◽  
J. Szabo ◽  
V. Namboodiri ◽  
E. R. Krishnan ◽  
J. Rodriguez ◽  
...  

Abstract Development of greener water treatment technologies is important for the production of safe drinking water and water security applications, such as decontamination. Chlorine assisted disinfection is common and economical, but can generate disinfection byproducts (DBPs) that may be of health concern. DBPs are formed due to the reaction of chlorine with naturally occurring organic and inorganic substances in water. Currently, various innovative technologies are being developed as alternative approaches for preventing DBPs during water treatment. In this study, we evaluated the effectiveness of a novel combination of high efficiency flow filtration and UV disinfection treatment system for the removal of Bacillus globigii (B. globigii) spores in water. The filtration system consists of a charged membrane filter (CMF) that not only helps to remove suspended particles but also reduces the impact of other impurities including bio organisms. In order to get most performance details, the CMF was evaluated at clean, half-life, and end of life (EOL) conditions along with 100% UV transmittance (UVT). In addition, the effectiveness of the UV system was evaluated as a stand alone system at 100% and 70% EOL intensity. The study was conducted at the US EPA's Test and Evaluation (T&E) Facility in Cincinnati, OH, using B. globigii, a surrogate for B. anthracis spores. This non-chemical environmentally-friendly CMF/UV combination system and the stand alone UV unit showed greater than 6.0 log removal of B. globigii during the tests.


Chemosphere ◽  
2019 ◽  
Vol 217 ◽  
pp. 111-121 ◽  
Author(s):  
Brooke K. Mayer ◽  
Carlan Johnson ◽  
Yu Yang ◽  
Nicole Wellenstein ◽  
Emily Maher ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2408
Author(s):  
Steven C. Chapra ◽  
Luis A. Camacho ◽  
Graham B. McBride

For rivers and streams, the impact of rising water temperature on biochemical oxygen demand (BOD) assimilative capacity depends on the interplay of two independent factors: the waterbody’s dissolved oxygen (DO) saturation and its self-purification rate (i.e., the balance between BOD oxidation and reaeration). Although both processes increase with rising water temperatures, oxygen depletion due to BOD oxidation increases faster than reaeration. The net result is that rising temperatures will decrease the ability of the world’s natural waters to assimilate oxygen-demanding wastes beyond the damage due to reduced saturation alone. This effect should be worse for nitrogenous BOD than for carbonaceous BOD because of the former’s higher sensitivity to rising water temperatures. Focusing on streams and rivers, the classic Streeter–Phelps model was used to determine the magnitude of the maximum or “critical” DO deficit that can be calculated analytically as a function of the mixing-point BOD concentration, DO saturation, and the self-purification rate. The results indicate that high-velocity streams will be the most sensitive to rising temperatures. This is significant because such systems typically occur in mountainous regions where they are also subject to lower oxygen saturation due to decreased oxygen partial pressure. Further, they are dominated by salmonids and other cold-water fish that require higher oxygen levels than warm-water species. Due to their high reaeration rates, such systems typically exhibit high self-purification constants and consequently have higher assimilation capacities than slower moving lowland rivers. For slow-moving rivers, the total sustainable mixing-point concentration for CBOD is primarily dictated by saturation reductions. For faster flowing streams, the sensitivity of the total sustainable load is more equally dependent on temperature-induced reductions in both saturation and self-purification.


Author(s):  
Lucile Duforêt-Gaurier ◽  
David Dessailly ◽  
William Moutier ◽  
Hubert Loisel

The bulk backscattering ratio ($\tilde{b_{bp}}$) is commonly used as a descriptor of the bulk real refractive index of the particulate assemblage in natural waters. Based on numerical simulations, we analyze the impact of heterogeneity of phytoplankton cells on $\tilde{b_{bp}}$. $\tilde{b_{bp}}$ is modeled considering viruses, heterotrophic bacteria, phytoplankton, detritus, and minerals. Three study cases are defined according to the relative abundance of these different components. Two study cases represent typical situations in open ocean, outside (No-B/No-M) and inside bloom (B/No-M). The third study case is typical of coastal waters with the presence of minerals. Phytoplankton cells are modeled by a two-layered spherical geometry representing a chloroplast surrounding the cytoplasm. The $\tilde{b_{bp}}$ values are higher when heterogeneity is considered because the contribution of coated spheres to backscattering is higher than homogeneous spheres. The impact of heterogeneity is however strongly conditioned by the hyperbolic slope $\xi$ of the particle size distribution. Even if the relative concentration of phytoplankton is small (<1%), $\tilde{b_{bp}}$ increases by about 60% (for $\xi=4.3$ and for the No-B/No-M water body), when the heterogeneity is taken into account, in comparison with a particulate population only composed by homogeneous spheres. As expected, heterogeneity has a much smaller impact (about 5$\%$ for $\xi=4.3$) on $\tilde{b_{bp}}$ when minerals are added.


Author(s):  
M. L. Bubarai U. Bapetel ◽  
A. Musa Mala

At the SHUATS Department of Soil Science and Agricultural Chemistry Research Farm, an experiment was conducted with the goal of determining the impact of application of macro and micronutrients, on soil health nutrients concentration and uptake by maize (Zea mays L). The experiment was put up based on this over a two-year period, beginning with the 2017 and 2018 cropping periods. Crbd was used as the experimental technique and it was replicated thrice with the following treatments combinations, NPK @ 50 and 100kgha -1, while for the micronutrients (Boron, Zinc and Copper) three levels of combination were used 0.3, 6 and 9kgha-1. The research project's findings showed all the determinants of soil health like soil reaction organic matter among others are at levels suitable for nutrients actions and plant growth, while plant parameters like maize cob diameter, dry matter, and nutrients concentrations in maize tissues have greatly improved. NPK @100kgha-1, Copper, Zinc, and Boron @ 9kgha-1 were the best treatment combinations with the best results. The above combinations of treatments will be suitable for the soils of that location based on the results of these studies.


Author(s):  
L. O. Bobor ◽  
C. M. Umeh

The indiscriminate disposal of industrial effluents and solid wastes in surface water bodies is detrimental to humans and aquatic organisms. Water quality monitoring is critical to identify pollutants of concern and develop effective management strategies. Hence, this study was conducted to assess the impact of waste disposal on the water quality of Aba Waterside River, Ogbor hill, Aba. Grab samples were collected upstream, midstream and downstream and some physicochemical and microbiological parameters were analyzed in accordance with standard methods for the analysis of water and wastewater. The results were compared with the Nigerian standard for drinking water quality and the national environmental effluent limitation regulations. Turbidity levels (10 -31mg/l) exceeded the maximum permissible levels for drinking water (5mg/l) and may be associated with higher levels of embedded disease-causing microbes and potentially harmful organic and inorganic substances. The biological oxygen demand midstream (1960mg/l) was remarkably high due to the effluent discharged from the abattoirs at that point. Fecal coliforms (3-198MPN/100ml) were detected in all samples, indicating the presence of other potentially harmful microorganisms. The findings of this study indicate that the water is unsuitable for direct drinking water purposes and stringent water quality control measures should be implemented.


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