scholarly journals Response of Chlorella Sp. to Nickel Pollution

1970 ◽  
Vol 25 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Pawan Raj Shakya ◽  
D Kaplan
Keyword(s):  
Metal Binding ◽  
Binding Capacity ◽  
Low Cost ◽  
Preliminary Investigation ◽  
Resistance Mechanisms ◽  
Green Microalgae ◽  
Toxic Heavy Metals ◽  
Chemical Methods ◽  
Chlorella Sp ◽  
Physico Chemical

Unicellular green microalgae are widely used these days for removing toxic heavy metals from the contaminated environment by virtue of their metal binding capacities confirming resistance mechanisms. Besides, they have several advantages over conventional physico-chemical methods such as ion exchange, precipitation with CaCO3, adsorption, flocculation, etc. The present study is a preliminary investigation regarding an attempt to provide low cost, efficient and an emerging eco-friendly technology for the removal of nickel from the nickel polluted environemtn by the use of (WT) Chlorella sp. and one of the isolated cell lines, EMS-10 of the same species. Growth experiments show the effect of increasing NI2+ concentration on the WT and EMS-10 cultures. However, the ID50 value of the EMS-10 revealed some degree of resistance to nickel. Kinetic experiments reveal effective metal binding capacity in EMS-10 and demonstrated appreciable resistance in response to the nickel toxicity as compared to the WT.Key words: Green microalgae; Physico-chemical methods; EMS-10Tribhuvan University Journal Vol. XXV, No. 1, 2005Page:129-139Uploaded date: 26, September, 2010

scholarly journals Contribution of Nanomaterials to the Development of Electrochemical Aptasensors for the Detection of Antimicrobial Residues in Food Products

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 69
Author(s):  
Valérie Gaudin
Keyword(s):  
Signal Amplification ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Food Products ◽  
Animal Origin ◽  
Screening Methods ◽  
Chemical Methods ◽  
Portable Instrumentation ◽  
Physico Chemical ◽  
Antimicrobial Residues

The detection of antimicrobial residues in food products of animal origin is of utmost importance. Indeed antimicrobial residues could be present in animal derived food products because of animal treatments for curative purposes or from illegal use. The usual screening methods to detect antimicrobial residues in food are microbiological, immunological or physico-chemical methods. The development of biosensors to propose sensitive, cheap and quick alternatives to classical methods is constantly increasing. Aptasensors are one of the major trends proposed in the literature, in parallel with the development of immunosensors based on antibodies. The characteristics of electrochemical sensors (i.e., low cost, miniaturization, and portable instrumentation) make them very good candidates to develop screening methods for antimicrobial residues in food products. This review will focus on the recent advances in the development of electrochemical aptasensors for the detection of antimicrobial residues in food products. The contribution of nanomaterials to improve the performance characteristics of electrochemical aptasensors (e.g., Sensitivity, easiness, stability) in the last ten years, as well as signal amplification techniques will be highlighted.

scholarly journals Bioremoval of Different Heavy Metals in Industrial Effluent by the Resistant Fungal Strain Aspergillus niger

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
K. J. Naveen Kumar ◽  
J. Prakash
Keyword(s):  
Heavy Metals ◽  
Aspergillus Niger ◽  
Metal Binding ◽  
Metal Removal ◽  
Low Cost ◽  
Heavy Metal Removal ◽  
Industrial Effluent ◽  
Toxic Metal ◽  
Differential Pulse ◽  
Toxic Heavy Metals

Developing countries are increasingly concerned with pollution due to toxic heavy metals in the environment. Unlike most organic pollutants which can be destroyed, toxic metal ions released into the environment often persist indefinitely circulating and eventually accumulating throughout the food chain thus posing a serious threat to mankind. The use of biological materials for heavy metal removal or recovery has gained importance in recent years due to their good performance and low cost. Among the various sources, both live and inactivated biomass of organisms exhibits interesting metal binding capacities. Their complex cell walls contain high content of functional groups like amino, amide, hydroxyl, carboxyl, and phosphate which have been implicated in metals binding. In the present study, Aspergillus niger was used to analyze the metal uptake from an aqueous solution. The determination of Cu+2, Pb+2, Cd+2, Zn+2, Co-2 and Ni+2 in samples was carried out by differential Pulse Anodic Voltammetry (DPASV) and the Voltammograms. Production of oxalic acid was carried out by submerged fermentation. The organism used in the present study has the ideal properties to sequester toxic metals and grow faster.

scholarly journals Lead Toxicity, Adsorption and Resistance in Chlorella Sp.

Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 156-166
Author(s):  
Pawan Raj Shakya ◽  
Neena Khwaounjoo
Keyword(s):  
Lead Toxicity ◽  
Intracellular Uptake ◽  
Green Microalgae ◽  
Wild Type ◽  
Toxic Heavy Metals ◽  
Ems Mutagenesis ◽  
Chlorella Sp ◽  
Internal Cell ◽  
Rapid Removal ◽  
Cell Fractions

These days, unicellular green microalgae have been widely used for removal of toxic heavy metals from contaminated soil and water bodies. In the present investigation, a lead resistant PbR-11 strain isolated from Chlorella sp. by EMS mutagenesis was compared against the wild type (WT) of the same species for Pb2+ accumulating capacity. Growth of both the tested algal cells, PbR-11 and WT (control) were found to be retarded with increasing Pb2+ concentrations in the medium. However, higher ID50 value of the PbR-11 exhibited some degree of resistance to the metal toxicity. When exposed to the liquid medium containing 50 mM Pb2+, kinetic experiments showed rapid removal and adsorption of the metal ions in both the algal cells during the first few hours. Compared to WT, the PbR-11 showed significantly higher percentage removal and adsorption of Pb2+ at 15 minutes and 48 hours interval of time respectively. Extracellular Pb2+ adsorption was found significantly higher than intracellular uptake in the tested algal cells although both the processes occurred simultaneously. Total Pb2+accumulation and distribution between the external and internal cell fractions of the PbR-11 were significantly higher to that of the WT. Thus, the strain appeared more useful for remediation of contaminated sites.DOI: http://dx.doi.org/10.3126/on.v10i1.7778

scholarly journals Chromatography-Independent Fractionation and Newly Identified Molecular Features of the Adzuki Bean (Vigna angularis Willd.) β-vignin Protein

2021 ◽  
Vol 22 (6) ◽  
pp. 3018
Author(s):  
Biane Philadelpho ◽  
Victória Souza ◽  
Fabiani Souza ◽  
Johnnie Santos ◽  
Fabiana Batista ◽  
...  
Keyword(s):  
Metal Binding ◽  
Cardiovascular Health ◽  
Binding Capacity ◽  
Biological Activities ◽  
Electrophoretic Analysis ◽  
Adzuki Bean ◽  
Molecular Features ◽  
Health Promoting ◽  
High Degree

Adzuki seed β-vignin, a vicilin-like globulin, has proven to exert various health-promoting biological activities, notably in cardiovascular health. A simple scalable enrichment procedure of this protein for further nutritional and functional studies is crucial. In this study, a simplified chromatography-independent protein fractionation procedure has been optimized and described. The electrophoretic analysis showed a high degree of homogeneity of β-vignin isolate. Furthermore, the molecular features of the purified protein were investigated. The adzuki bean β-vignin was found to have a native size of 146 kDa, and the molecular weight determined was consistent with a trimeric structure. These were identified in two main polypeptide chains (masses of 56–54 kDa) that are glycosylated polypeptides with metal binding capacity, and one minor polypeptide chain with a mass 37 kDa, wherein these features are absent. The in vitro analysis showed a high degree of digestibility of the protein (92%) and potential anti-inflammatory capacity. The results lay the basis not only for further investigation of the health-promoting properties of the adzuki bean β-vignin protein, but also for a possible application as nutraceutical molecule.

scholarly journals Enhanced Oil Removal by a Non-Toxic Biosurfactant Formulation

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 467
Author(s):  
Emília Mendes da Silva Santos ◽  
Isabela Regina Alvares da Silva Lira ◽  
Hugo Moraes Meira ◽  
Jaciana dos Santos Aguiar ◽  
Raquel Diniz Rufino ◽  
...  
Keyword(s):  
Room Temperature ◽  
Low Cost ◽  
Aeration Rate ◽  
Oil Removal ◽  
Central Composite Rotatable Design ◽  
Chemical Methods ◽  
Ph Values ◽  
Spectroscopic Analyses ◽  
New Formulation ◽  
Central Composite

In this study, a new formulation of low-cost, biodegradable, and non-toxic biosurfactant by Candida sphaerica UCP 0995 was investigated. The study was conducted in a bioreactor on an industrial waste-based medium, and a central composite rotatable design was used for optimization. The best results, namely a 25.22 mN/m reduction in surface tension, a biosurfactant yield of 10.0 g/L, and a critical micelle concentration of 0.2 g/L, were achieved in 132 h at an agitation speed of 175 rpm and an aeration rate of 1.5 vvm. Compositional and spectroscopic analyses of the purified biosurfactant by chemical methods, Fourier transform infrared spectroscopy, and nuclear magnetic resonance suggested that it is a glycolipid-type biosurfactant, and it showed no cytotoxicity in the MTT assay. The biosurfactant, submitted to different formulation methods as a commercial additive, remained stable for 120 days at room temperature. Tensioactive properties and stability were evaluated at different pH values, temperatures, and salt concentrations. The biosurfactant obtained with all formulation methods demonstrated good stability, with tolerance to wide ranges of pH, temperature and salinity, enabling application under extreme environmental conditions. Bioremediation tests were performed to check the efficacy of the isolated biosurfactant and the selected microbial species in removing oil from soil. The results demonstrated that the biosurfactant produced has promising properties as an agent for the bioremediation of contaminated soil.

scholarly journals Preparation and Antimicrobial Activity of Chitosan and Its Derivatives: A Concise Review

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3694
Author(s):  
Luminita Georgeta Confederat ◽  
Cristina Gabriela Tuchilus ◽  
Maria Dragan ◽  
Mousa Sha’at ◽  
Oana Maria Dragostin
Keyword(s):  
Antimicrobial Activity ◽  
Low Cost ◽  
Hydroxyl Groups ◽  
Pharmacological Properties ◽  
Natural Polymers ◽  
Economic Sectors ◽  
Physico Chemical ◽  
Long Time ◽  
Resistant Strains ◽  
Strength And Durability

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

scholarly journals The principle of formaldehyde, alcohol, and acetone titrations. With a discussion of the proof and implication of the zwitterion conception

1934 ◽  
Vol 115 (792) ◽  
pp. 121-141 ◽  
Keyword(s):  
Amino Acids ◽  
Carboxyl Groups ◽  
Recent Discussion ◽  
Amino Groups ◽  
Chemical Methods ◽  
Titration Method ◽  
Physico Chemical ◽  
Empirical Argument ◽  
Chemical Evidence

Consideration of the implications of the zwitterion hypothesis of Bjerrum (1923) makes it desirable to state afresh the principles underlying the methods commonly employed in the titration of amino-acids. Deductions of considerable theoretical importance, cf., e. g ., Calvery (1933) are still being made on the supposition that the alkalimetric formaldehyde titration method of Sørensen (1907) and the corresponding alcohol method of Foreman (1920) and of Willstätter and Waldschmidt-Leitz (1921) estimate the carboxyl groups of amino-acids whilst the acidimetric acetone titration of Linderstrøm-Lang (1928) estimates the amino-groups. Yet the zwitterion hypothesis indicates that this assumption is the reverse of the truth. Discussion is greatly facilitated by collective consideration of recent physico-chemical evidence clarifying the principles upon which these common bio-chemical methods rest. In a recent discussion of two of the titrimetric methods (Van Slyke and Kirk, 1933) the existence of this evidence is ignored, so that it becomes necessary to systematize and elaborate the empirical argument of these authors in the light of the relevant investigations of Grünhut (1919), Cray and Westrip (1925), Michaelis and Mizutani (1925), Birch and Harris (1930, b ), and Levy (1933). At the same time new and useful developments are indicated.

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