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Mechanistic insight to mycoremediation potential of a metal resistant fungal strain for removal of hazardous metals from multimetal pesticide matrix
2020
Dey, Priyadarshini | Malik, Anushree | Mishra, Abhishek | Singh, Dileep Kumar | von Bergen, Martin | Jehmlich, Nico
Fungi have an exceptional capability to flourish in presence of heavy metals and pesticide. However, the mechanism of bioremediation of pesticide (lindane) and multimetal [mixture of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn)] by a fungus is little understood. In the present study, Aspergillus fumigatus, a filamentous fungus was found to accumulate heavy metals in the order [Zn(98%)>Pb(95%)>Cd(63%)>Cr(62%)>Ni(46%)>Cu(37%)] from a cocktail of 30 mg L⁻¹ multimetal and lindane (30 mg L⁻¹) in a composite media amended with 1% glucose. Particularly, Pb and Zn uptake was enhanced in presence of lindane. Remarkably, lindane was degraded to 1.92 ± 0.01 mg L⁻¹ in 72 h which is below the permissible limit value (2.0 mg L⁻¹) for the discharge of lindane into the aquatic bodies as prescribed by European Community legislation. The utilization of lindane as a cometabolite from the complex environment was evident by the phenomenal growth of the fungal pellet biomass (5.89 ± 0.03 g L⁻¹) at 72 h with cube root growth constant of fungus (0.0211 g¹/³ L⁻¹/³ h⁻¹) compared to the biomasses obtained in case of the biotic control as well as in presence of multimetal complex without lindane. The different analytical techniques revealed the various stress coping strategies adopted by A. fumigatus for multimetal uptake in the simultaneous presence of multimetal and pesticide. From the Transmission electron microscope coupled energy dispersive X-ray analysis (TEM-EDAX) results, uptake of the metals Cd, Cu and Pb in the cytoplasmic membrane and the accumulation of the metals Cr, Ni and Zn in the cytoplasm of the fungus were deduced. Fourier-transform infrared spectroscopy (FTIR) revealed involvement of carboxyl/amide group of fungal cell wall in metal chelation. Thus A. fumigatus exhibited biosorption and bioaccumulation as the mechanisms involved in detoxification of multimetals.
اظهر المزيد [+] اقل [-]Triazole resistance in Aspergillus fumigatus in crop plant soil after tebuconazole applications
2020
Cao, Duantao | Wu, Ruilin | Dong, Suxia | Wang, Feiyan | Ju, Chao | Yu, Sumei | Xu, Shiji | Fang, Hua | Yu, Yunlong
Aspergillus fumigatus is the primary agent of invasive aspergillosis (IA) causing high morbidity and mortality in immunocompromised patients. Triazole resistance in A. fumigatus and its sources have gained wide attention. For several years, environmental fungicides use has been proposed as the major cause for triazole resistance in A. fumigatus. However, there are few studies on azole-resistant A. fumigatus (ARAF) selected by triazole fungicides in agricultural systems. We studied the possible emergence of ARAF in the field after exposure to triazole fungicide tebuconazole. Our results showed that exposure to tebuconazole in soil selects for resistance to triazoles in A. fumigatus. The probability of ARAF developing in soils depends upon the concentrations of tebuconazole after application. We suggest that tebuconazole applications should be minimized to reduce selective pressure for the generation of ARAFs.
اظهر المزيد [+] اقل [-]The assessment of airborne bacterial and fungal contamination emitted by a municipal landfill site in Northern Poland
2016
Breza-Boruta, B.
Airborne bacteria and fungi are important biological components of bioaerosol and play an important role in the conservation environmental. A microbiological study on bioaerosoles was carried out at the Municipal Waste Utilization Plant in Northern Poland and at points located beyond the facility at the distance of 150, 450, 1000 and 1250 m. The highest emission of bioaerosol occurred in the area of the waste landfill site and during compost pile turning. The total number of mesophilic bacteria, filamentous fungi and actinomycetes reached the values up to 104 CFU/m3. Strong air contamination with mannitol-positive and mannitol-negative staphylococci occurred remarkably more frequently in the area of the test facility than in the points beyond it. The number of indicator bacteria of Pseudomonas fluorescens was quite changeable and did not depend on a distance from pollutant emission source. The number of Escherichia coli rods remained at the low level of about 102 CFU/m3, and they were only isolated sporadically in the points beyond the landfill. The highest percentage of bacterial aerosol comprised Gram-positive cocci, and then Gram-positive bacilli. Mycological analyses confirmed the presence in the studied air of fungi with potentially allergic and mycotoxinogenic properties, such as: Aspergillus fumigatus, A. niger, A. terreus, Cladosporium herbarum and the genus Fusarium. The concentration level of microbial bioaerosol several times exceeded the threshold values recommended by the Polish Standards. The factors influenced the concentration of microorganisms in the tested air included the distance of the active landfill, weather conditions and the season.
اظهر المزيد [+] اقل [-]Enhanced Bioremediation of Heavy Metal Contaminated Landfill Soil Using Filamentous Fungi Consortia: a Demonstration of Bioaugmentation Potential
2019
Hassan, Auwalu | Pariatamby, Agamuthu | Ahmed, Aziz | Auta, Helen Shnada | Hamid, Fauziah Shahul
This study aimed to determine the mycoremediative capacity of filamentous fungi consortia in landfill heavy metal contaminated soil. Streak plate method was utilized for the isolation of fungi from the landfill soil. Isolates were identified using morphological and molecular techniques. Heavy metal tolerance of the fungi was determined using radial growth diameter technique. Twelve species of landfill indigenous fungi were used for the bioremediation process. Two categories of fungi consortia namely highly tolerant fungi (Perenniporia subtephropora, Daldinia starbaeckii, Phanerochaete concrescens, Cerrena aurantiopora, Fusarium equiseti, Polyporales sp., Aspergillus niger, Aspergillus fumigatus, and Trametes versicolor) and moderately tolerant fungi (Paecilomyces lilacinus, Antrodia serialis, and Penicillium cataractum) were used to amend the contaminated soil; meanwhile, the unamended soil served as control. Maximum tolerance index of 1.0 was reported in Cr-, Cu-, and Fe-amended PDA medium. Meanwhile, the maximum heavy metal bioremoval efficiencies were for highly tolerant fungal consortium treated soil and were recorded as As (62%) > Mn (59%) > Cu (49%) > Cr (42%) > Fe (38%). Likewise, the maximum metal removal rate constant (K) and the half-lives (t₁/₂) were 0.0097/day 71 days, 0.0088/day 79 days, 0.0067/day 103 days, 0.0054/day 128 days, and 0.0048/day 144 days for As, Mn, Cu, Cr, and Fe, respectively, which were all for soil treated with consortium of highly tolerant fungi (P. subtephropora, D. starbaeckii, P. concrescens, C. aurantiopora, F. equiseti, Polyporales sp., A. niger, A. fumigatus, and T. versicolor). Spectra analysis revealed a clear distinction in the functional groups between the fungal treated and the untreated soils. Peaks at 874 ± 2 cm⁻¹ and 1425 ± 2 cm⁻¹ were only found in fungi amended soil. Physicochemical parameters mainly pH and redox potential played a key role in the bioremediation process, and bioaccumulation was believed to be the favored mechanism for the metal bioremoval. The data are suitable for assessing the contribution of bioaugmentation with consortia of fungi. It is equally important for assessing the synergistic effect of fungi on the reduction of extractable heavy metals in contaminated soil.
اظهر المزيد [+] اقل [-]Exposure to Bioaerosol from Sewage Systems
2010
Haas, Doris | Unteregger, Martina | Habib, Juliana | Galler, Herbert | Marth, Egon | Reinthaler, Franz F.
Bioaerosols are conglomerates of biological particles such as bacterial and fungal propagules and are produced in sewers and sewage treatment plants through evaporation and turbulence. In order to evaluate the hazard to employees in wastewater treatment plants, airborne microorganisms were measured at two different sites in the sewage systems and in the grit chamber of a treatment plant. Two additional samples were taken during high-pressure cleaning in the relief sewer. Outdoor air samples served as background values. Airborne microorganisms were collected using the impaction method with the MAS-100® and the impingement method with the SKC Biosampler®. The concentrations of coliform bacteria as well as the fungal species Aspergillus fumigatus were determined in addition to mesophilic bacteria counts (cfu/m³). The highest concentrations of mesophilic bacteria were found in the encased grit chamber. Coliform bacteria were found infrequently only in the aerosol of the sewage systems; A. fumigatus was detected at all sampling sites both indoors as well as outdoors. During high-pressure cleaning, total bacteria concentrations reached up to 4.0 × 104 cfu/m3, coliforms up to 3.0 × 103 cfu/m3. These results show that personnel protective measures should be recommended to decrease the exposure risk to biological particles.
اظهر المزيد [+] اقل [-]Increase in Total Petroleum Hydrocarbons Removal Rate in Contaminated Mining Soil Through Bioaugmentation with Autochthonous Fungi During the Slow Bioremediation Stage
2021
Hernández-Adame, N. M. | López-Miranda, J. | Martínez-Prado, M. A. | Cisneros-de la Cueva, S. | Rojas-Contreras, J. A. | Medrano-Roldán, H.
The removal of total petroleum hydrocarbons (TPHs) from contaminated mining soil was carried out under in vitro conditions. The aerobic consumption of TPH in the slow bioremediation stage via biostimulation with native microorganisms and biostimulation-bioaugmentation with autochthonous fungal isolates was evaluated. The initial TPH concentration was 70,880 ± 975 mg TPH/kg soil, soil was amended with nutrients at a C:N:P ratio of 100:15:1, the water content was adjusted to the soil field capacity, and batch microcosm reactors were incubated at room temperature (20.5 ± 3.1°C) for 90 days. The bioaugmentation process was tested using four hydrocarbonoclastic fungal strains isolated from the same contaminated mining soil individually and a mixed culture of the four isolates. The molecular characterization of the isolated fungi was based on sequence analysis of 18S rRNA, and the fungi were identified as Aspergillus niger MT786339.1, Aspergillus fumigatus MT786338.1, Aspergillus terreus MT786341.1, and Aspergillus flavus MT786340.1. The best TPH removal was achieved by inoculation with the fungal consortium (57 ± 1.97%) at 45 days (slow stage) after initiating the biostimulation process, followed by inoculation with Aspergillus niger (49 ± 1.2%), Aspergillus terreus (44 ± 0.67%), Aspergillus fumigatus (35 ± 0.98%), and Aspergillus flavus (32 ± 0.38%), while the degradation rate achieved with native microorganisms was only 21.6 ± 1.5%; statistical analysis of the results showed significant differences.
اظهر المزيد [+] اقل [-]Selection of inactivation medium for fungal spores in clinical wastes by supercritical carbon dioxide
2018
Noman, Efaq | Norulaini Nik Ab Rahman, Nik | Al-Gheethi, Adel | Nagao, Hideyuki | Talip, Balkis A. | Ab. Kadir, Omar
The present study aimed to select the best medium for inactivation of Aspergillus fumigatus, Aspergillus spp. in section Nigri, A. niger, A. terreus var. terreus, A. tubingensis, Penicillium waksmanii, P. simplicissimum, and Aspergillus sp. strain no. 145 spores in clinical wastes by using supercritical carbon dioxide (SC-CO₂). There were three types of solutions used including normal saline, seawater, distilled water, and physiological saline with 1% of methanol; each solution was tested at 5, 10, and 20 mL of the water contents. The experiments were conducted at the optimum operating parameters of supercritical carbon dioxide (30 MPa, 75 °C, 90 min). The results showed that the inactivation rate was more effective in distilled water with the presence of 1% methanol (6 log reductions). Meanwhile, the seawater decreases inactivation rate more than normal saline (4.5 vs. 5.1 log reduction). On the other hand, the experiments performed with different volumes of distilled water (5, 10, and 20 mL) indicated that A. niger spores were completely inactivated with 10 mL of distilled water. The inactivation rate of fungal spores decreased from 6 to 4.5 log as the amount of distilled water increased from 10 to 20 mL. The analysis for the spore morphology of A. fumigatus and Aspergillus spp. in section Nigri using scanning electron microscopy (SEM) has revealed the role of temperature and pressure in the SC-CO₂ in the destruction of the cell walls of the spores. It can be concluded that the distilled water represent the best medium for inactivation of fungal spores in the clinical solid wastes by SC-CO₂.
اظهر المزيد [+] اقل [-]Assessment of relevant fungal species in clinical solid wastes
2016
Noman, Efaq Ali | Al-Gheethi, AA | Norulaini Nik Ab. Rahman, | Nagao, H | Ab. Kadir, MO
The study aimed to determine the fungal diversity in clinical waste samples from a healthcare facility in Penang Malaysia. Different fungi species were detected in 83.75 % of the 92 clinical waste samples that were screened from different sections of the healthcare facility. One hundred fifty fungal isolates comprising of 8 genera and 36 species were obtained. They were purified by using single spore isolation technique. Subsequently, the isolates were identified by phenotypic method based on morphological and culture characteristics on different culture media. Among all fungal isolates, Aspergillus spp. in section Nigri 10.2 %, Aspergillus niger 9.5 %, Aspergillus fumigatus 8.8 %, Penicillium. simplicissium 8 %, Aspergillus tubingensis 7.3 %, Aspergillus terreus var. terreus 6.6 %, Penicillium waksmanii 5.9 % and Curvularia lunata 6.5 % were the most frequent. Among five sections of the Wellness Centre, the clinical wastes collected from the diagnostic labs of haematology section had the highest numbers of fungal species (29 species). Glove wastes had the highest numbers of fungal species (19 species) among 17 types of clinical wastes screened. Among all fungal species, Aspergillus spp. exhibited higher growth at 37 °C than at 28 °C, indicating the potential of these opportunistic fungi to cause diseases in human. These results indicated the potential of hospital wastes as reservoirs for fungal species.
اظهر المزيد [+] اقل [-]Biodegradation of pesticides using fungi species found in the aquatic environment
2015
Oliveira, B. R. | Penetra, A. | Cardoso, V. V. | Benoliel, M. J. | Barreto Crespo, M. T. | Samson, R. A. | Pereira, V. J.
Relatively limited attention has been given to the presence of fungi in the aquatic environment compared to their occurrence in other matrices. Taking advantage and recognizing the biodegradable capabilities of fungi is important, since these organisms may produce many potent enzymes capable of degrading toxic pollutants. Therefore, the aim of this study was to evaluate the potential ability of some species of filamentous fungi that occur in the aquatic environment to degrade pesticides in untreated surface water. Several laboratory-scale experiments were performed using the natural microbial population present in the aquatic environment as well as spiked fungi isolates that were found to occur in different water matrices, to test the ability of fungi to degrade several pesticides of current concern (atrazine, diuron, isoproturon and chlorfenvinphos). The results obtained in this study showed that, when spiked in sterile natural water, fungi were able to degrade chlorfenvinphos to levels below detection and unable to degrade atrazine, diuron and isoproturon. Penicillium citrinum, Aspergillus fumigatus, Aspergillus terreus and Trichoderma harzianum were found to be able to resist and degrade chlorfenvinphos. These fungi are therefore expected to play an important role in the degradation of this and other pollutants present in the aquatic environment.
اظهر المزيد [+] اقل [-]Volatile organic compounds and bioaerosols in the vicinity of a municipal waste organic fraction treatment plant. Human health risks
2012
Vilavert, Lolita | Nadal, Martí | Figueras, María J. | Domingo, José L.
PURPOSE: The aim of this study was to analyze air concentrations of chemical and microbiological pollutants in the vicinity of an organic waste treatment plant, Ecoparc-2, located in Montcada i Reixac (Catalonia, Spain), as well as to determine the seasonal trends. The human health risks due to the presence of those agents were also assessed. METHODS: Air samples were collected at different distances and wind directions from the Ecoparc-2 in two campaigns (winter and summer of 2010). The levels of 19 volatile organic compounds (VOCs) were analyzed by GC-MS or HPLC-UV. In turn, the airborne amount of total bacteria, gram-negative bacteria, and fungi (including Aspergillus fumigatus) was also determined. RESULTS: Mean VOC concentrations were found to be 32.4 and 15.7 μg/m3 in winter and summer, respectively. Fungi at 25°C presented the highest geometric mean (1,126 and 863 cfu/m3 in winter and summer, respectively), while the concentrations of fungi at 37°C and total bacteria were also important in the hot season (332 and 250 cfu/m3, respectively). These results are in agreement with data obtained from the scientific literature. Anyhow, no significant differences were observed between both campaigns including those related to distances and wind directions. The current pollutant levels in the surrounding environment were also various orders of magnitude lower than those recently observed inside the facility. CONCLUSIONS: The human exposure to VOCs near the Ecoparc-2 was estimated to be low. Furthermore, the current environmental concentrations of those chemical and microbiological agents were clearly below threshold values recommended by regulatory organizations.
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