scholarly journals The first recorded incidence of Deinococcus radiodurans R1 biofilm formation and its implications in heavy metals bioremediation

2017 ◽  
Author(s):  
Sudhir K. Shukla ◽  
T. Subba Rao
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Biofilm Formation ◽  
Deinococcus Radiodurans ◽  
Extracellular Dna ◽  
Metal Biosorption ◽  
Removal Of Heavy Metals ◽  
The Matrix ◽  
Heavy Metal Biosorption ◽  
Biofilm Matrix

AbstractRadiation tolerant Deinococcus radiodurans R1 is reported to be a potential bacterium for the treatment of low level active wastes. So far there are no reports on the biofilm producing capability of D. radiodurans and heavy metal biosorption. In this study, it was observed that a recombinant D. radiodurans strain with a plasmid harbouring gfp and kanR has formed significant biofilm (~10 μm thick). Analysis of biofilm matrix components produced by D. radiodurans showed that the matrix consisted primarily of proteins and carbohydrates with a little amount of extracellular DNA (eDNA). Further, studies showed that D. radiodurans biofilm formation was enhanced at higher concentrations (up to 25 mM) of Ca2+. Further studies on D. radiodurans biofilm showed that Ca2+ enhanced significant biosorption of the heavy metals (Co, Ni). In the presence of 25 mM Ca2+, the D. radiodurans (Kanr) biofilm showed 35% and 25% removal of Co2+ and Ni2+ respectively. While in the absence of Ca2+, D. radiodurans biofilm showed relatively low biosorption of Co (7%) and Ni (3%). Ca2+ also significantly enhanced exopolysaccharide (EPS) production in the biofilm matrix. This infers that EPS could have mediated the heavy metal biosorption. This study signifies the potential use of D. radiodurans biofilm in the remediation of radioactive waste components.Significance and Impact of this StudyThis is the first ever recorded study on the Deinococcus radiodurans R1 biofilm. This organism, being the most radioresistant micro-organism ever known, has always been speculated as a potential bacterium to develop a bioremediation process for radioactive heavy metal contaminants. However, the lack of biofilm forming capability proved to be a bottleneck in developing such technology. This study records the first incidence of biofilm formation in a recombinant D. radiodurans, serendipitously, and also discusses its implications in removal of heavy-metals, such as Co and Ni.

scholarly journals An Electrostatic Net Model for the Role of Extracellular DNA in Biofilm Formation by Staphylococcus aureus

2015 ◽  
Vol 197 (24) ◽  
pp. 3779-3787 ◽  
Author(s):  
Vanina Dengler ◽  
Lucy Foulston ◽  
Alicia S. DeFrancesco ◽  
Richard Losick
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Extracellular Dna ◽  
Matrix Proteins ◽  
Exogenous Dna ◽  
Content Type ◽  
Cytoplasmic Proteins ◽  
The Matrix ◽  
Biofilm Matrix

ABSTRACTStaphylococcus aureusis an important human pathogen that can form biofilms on various surfaces. These cell communities are protected from the environment by a self-produced extracellular matrix composed of proteins, DNA, and polysaccharide. The exact compositions and roles of the different components are not fully understood. In this study, we investigated the role of extracellular DNA (eDNA) and its interaction with the recently identified cytoplasmic proteins that have a moonlighting role in the biofilm matrix. These matrix proteins associate with the cell surface upon the drop in pH that naturally occurs during biofilm formation, and we found here that this association is independent of eDNA. Conversely, the association of eDNA with the matrix was dependent on matrix proteins. Both proteinase and DNase treatments severely reduced clumping of resuspended biofilms; highlighting the importance of both proteins and eDNA in connecting cells together. By adding an excess of exogenous DNA to DNase-treated biofilm, clumping was partially restored, confirming the crucial role of eDNA in the interconnection of cells. On the basis of our results, we propose that eDNA acts as an electrostatic net, interconnecting cells surrounded by positively charged matrix proteins at a low pH.IMPORTANCEExtracellular DNA (eDNA) is an important component of the biofilm matrix of diverse bacteria, but its role in biofilm formation is not well understood. Here we report that inStaphylococcus aureus, eDNA associates with cells in a manner that depends on matrix proteins and that eDNA is required to link cells together in the biofilm. These results confirm previous studies that showed that eDNA is an important component of theS. aureusbiofilm matrix and also suggest that eDNA acts as an electrostatic net that tethers cells together via the proteinaceous layer of the biofilm matrix.

Applications of Bentonite to Soil Decontamination

2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Laboratory Experiments ◽  
Experimental Studies ◽  
Heavy Metal Concentration ◽  
Polluted Soil ◽  
Raw Material ◽  
Soil Decontamination ◽  
Metal Retention ◽  
Removal Of Heavy Metals

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.

scholarly journals A systematic study for removal of heavy metals from aqueous media using Sorghum bicolor: an efficient biosorbent

2018 ◽  
Vol 77 (10) ◽  
pp. 2355-2368 ◽  
Author(s):  
Khalida Naseem ◽  
Zahoor H. Farooqi ◽  
Muhammad Z. Ur Rehman ◽  
Muhammad A. Ur Rehman ◽  
Robina Begum ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Aqueous Media ◽  
Review Article ◽  
Isotherm Models ◽  
Adsorption Efficiency ◽  
Adsorption Isotherm Models ◽  
Removal Of Heavy Metals

Abstract This review is based on the adsorption characteristics of sorghum (Sorghum bicolor) for removal of heavy metals from aqueous media. Different parameters like pH, temperature of the medium, sorghum concentration, sorghum particle size, contact time, stirring speed and heavy metal concentration control the adsorption efficiency of sorghum biomass for heavy metal ions. Sorghum biomass showed maximum efficiency for removal of heavy metal ions in the pH range of 5 to 6. It is an agricultural waste and is regarded as the cheapest biosorbent, having high adsorption capacity for heavy metals as compared to other reported adsorbents, for the treatment of heavy metal polluted wastewater. Adsorption of heavy metal ions onto sorghum biomass follows pseudo second order kinetics. Best fitted adsorption isotherm models for removal of heavy metal ions on sorghum biomass are Langmuir and Freundlich adsorption isotherm models. Thermodynamic aspects of heavy metal ions adsorption onto sorghum biomass have also been elaborated in this review article. How adsorption efficiency of sorghum biomass can be improved by different physical and chemical treatments in future has also been elaborated. This review article will be highly useful for researchers working in the field of water treatment via biosorption processing. The quantitative demonstrated efficiency of sorghum biomass for various heavy metal ions has also been highlighted in different sections of this review article.

scholarly journals Treatment of Poultry Wastewater Using Shells from African Cherry Seeds, Egg and Crab

2020 ◽  
pp. 16-30
Author(s):  
Abimbola O. Aleshinloye ◽  
Kemayou Ngangsso ◽  
Feyisara B. Adaramola ◽  
Adebayo Onigbinde
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Microwave Plasma ◽  
Low Cost ◽  
Chloride Content ◽  
Agricultural Wastes ◽  
Wastewater Sample ◽  
Animal Source ◽  
Removal Of Heavy Metals ◽  
Poultry Wastewater

This study investigated the potential of some agricultural wastes viz; African Star apple seed shell (ASS, plant source), crab shell (CS, animal source) and chicken egg shell (ES, animal source) as eco-friendly and low-cost biological materials for the removal of heavy metals from poultry wastewater. TS, TSS and TDS of the wastewater sample were assayed by filtration methods, chloride content by previously reported method and heavy metal contents (Zn, V, Cd, Fe, Ni, Cu, Co, Pb, Cr and Mn); were analyzed using Microwave Plasma Atomic Emission Spectrometer. The results of the solids and chloride contents of the poultry wastewater were TDS (3100 mg/L), TS (3700 mg/L), TSS (6000 mg/L) and chloride (4.7 g/L); all above the EPA permissible limits. Results of the FTIR analysis showed that ASS is an amide polymer while the CS and ES shells are mixtures of amide and carbonate polymers. Also, results of heavy metal analysis before and after adsorption showed that ASS caused removal of Zn, V, Fe, Cu, Co/ Pb and Mn by 48.27, 32.22, 49.64, 91.44, 100 and 82.39% respectively while Cd, Ni and Cr contents increased by 31, 61 and 48.3% respectively. CS showed removal of Fe, Ni/ Co/ Cr, Pb and Mn by 89.64, 100, 3.51 and 95.96% respectively while Zn, V, Cd and Cu contents increased by 1.7, 61.2, 76.1 and 68.1% respectively. Meanwhile, with ES, the contents of Zn, Fe, Ni, Cu, Cr and Mn increased by 31.56, 86.36, 100, 55.5, 45.80 and 90.33% respectively while the contents of V, Cd, Co and Pb decreased by 78.9, 86.7, 42.5 and 46.2% respectively. This study demonstrated the use of ASS, CS and ES as low- cost and eco-friendly agricultural wastes with significant potential for removal of heavy metals from wastewaters.

Heavy metal removal from wastewater and leachate co-treatment sludge by sulfur oxidizing bacteria

2001 ◽  
Vol 44 (10) ◽  
pp. 53-58 ◽  
Author(s):  
L. C. Aralp ◽  
A. Erdincler ◽  
T. T. Onay
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Heavy Metal Concentration ◽  
Organic Content ◽  
Removal Of Heavy Metals ◽  
Sulfur Oxidizing ◽  
Sulfur Oxidizing Bacteria

Heavy metal concentration in sludge is one of the major obstacles for the application of sludge on land. There are various methods for the removal of heavy metals in sludge. Using sulfur oxidizing bacteria for microbiological removal of heavy metals from sludges is an outstanding option because of high metal solubilization rates and the low cost. In this study, bioleaching by indigenous sulfur oxidizing bacteria was applied to sludges generated from the co-treatment of municipal wastewater and leachate for the removal of selected heavy metals. Sulfur oxidizing bacteria were acclimated to activated sludge. The effect of the high organic content of leachate on the bioleaching process was investigated in four sets of sludges having different concentrations of leachate. Sludges in Sets A, B, C and D were obtained from co-treatment of wastewater and 3%, 5%, 7% and 10% (v/v) leachate respectively. The highest Cr, Ni and Fe solubilization was obtained from Set A. Sulfur oxidizing bacteria were totally inhibited in Set D that received the highest volume of leachate.

scholarly journals Bioremoval of Different Heavy Metals by the Resistant Fungal StrainAspergillus niger

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ismael Acosta-Rodríguez ◽  
Juan F. Cárdenas-González ◽  
Adriana S. Rodríguez Pérez ◽  
Juana Tovar Oviedo ◽  
Víctor M. Martínez-Juárez
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Aspergillus Niger ◽  
Fungal Biomass ◽  
Dry Weight ◽  
Removal Capacity ◽  
Removal Of Heavy Metals ◽  
The Ideal

The objective of this work was to study the resistance and removal capacity of heavy metals by the fungusAspergillus niger. We analyzed the resistance to some heavy metals by dry weight and plate: the fungus grew in 2000 ppm of zinc, lead, and mercury, 1200 and 1000 ppm of arsenic (III) and (VI), 800 ppm of fluor and cobalt, and least in cadmium (400 ppm). With respect to their potential of removal of heavy metals, this removal was achieved for zinc (100%), mercury (83.2%), fluor (83%), cobalt (71.4%), fairly silver (48%), and copper (37%). The ideal conditions for the removal of 100 mg/L of the heavy metals were 28°C, pH between 4.0 and 5.5, 100 ppm of heavy metal, and 1 g of fungal biomass.

Electronic Tongue-FIA system for the Monitoring of Heavy Metal Biosorption Processes

2011 ◽  
Author(s):  
D. Wilson ◽  
A. Florido ◽  
C. Valderrama ◽  
M. Fernández de Labastida ◽  
S. Alegret ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Electronic Tongue ◽  
Metal Biosorption ◽  
Heavy Metal Biosorption
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