Electrochemical Magnetic Immunoassay for the Determination of the Fish Allergen β-Parvalbumin.

β-parvalbumin (β-PV) is the primary fish allergen responsible for most allergic reactions in individuals sensitive to fish. To ensure food safety, a sandwich-based magnetic immunoassay was developed using maleimide-functionalized magnetic beads (NH-MBs). Specific anti-β-PV antibodies were immobilized on these MBs, and a screen-printed carbon electrode was employed as the electrochemical transducer.

Electrochemical Sensors Based on Transition Metal Materials for Phenolic Compound Detection.

Electrochemical sensors have been recognized as crucial tools for monitoring comprehensive chemical information, especially in the detection of a significant class of molecules known as phenolic compounds. These compounds can be present in water as hazardous analytes and trace contaminants, as well as in living organisms where they regulate their metabolism. The sensitive detection of phenolic compounds requires highly efficient and cost-effective electrocatalysts to enable the development of high-performance sensors.

Cobalt-nickel phosphide supported on reduced graphene oxide for sensitive electrochemical detection of bisphenol A.

Bisphenol A (BPA) is a commonly utilized phenolic contaminant in several manufacturing processes, contributing to environmental pollution. Therefore, the detection of BPA holds significant importance for monitoring water quality. In this work, we report a robust electrochemical detection method for BPA utilizing cobalt-nickel bimetal phosphide nanoparticles (CoNiP) supported on reduced graphene oxide (rGO).

Facile preparation of a Pt-ERGO composite modified screen-printed electrode for the sensitive determination of phenolic compounds.

The mass production of screen-printed electrochemical devices with integrated electrodes has facilitated the widespread adoption of electroanalytical methods. The SPEs (screen-printed electrodes) overcome some obstacles associated with the use of conventional electrochemical cells, making them accessible to untrained operators. Despite their advantages, SPEs require activation/modification of the working electrode (WE) to enhance sensitivity.

Behavior of deteriogenic fungi in aviation fuels (fossil and biofuel) during simulated storage.

Biofuels are expected to play a major role in reducing carbon emissions in the aviation sector globally. Farnesane ("2,6,10-trimethyldodecane") is a biofuel derived from the synthesized iso-paraffin route wich can be blended with jet fuel; however, the microbial behavior in farnesane/jet fuel blends remains unknown. The chemical and biological stability of blends should be investigated to ensure they meet the quality requirements for aviation fuels.

Developing a Compost Quality Index (CQI) Based on the Electrochemical Quantification of Cd (HA) Reactivity.

The present work demonstrates the use of Cd as a reactivity probe of the fulvic acids (FAs), humic acids (HAs) and dissolved organic matter (DOM) compost extracts. Significant differences were observed between the extracts, with the HA extract showing the highest reactivity. Comparing the different composts, the largest reactivity variation was again observed for HA then FA and finally DOM extracts.

Characterization of antimicrobial effect of organotin-based catalysts on diesel-biodiesel deteriogenic microorganisms.

Organotin compounds are applied in several industrial reactions and can present antifungal and antibacterial activities. Incorrect handling and storage practices of biodiesel and diesel-biodiesel blends can lead to microbial development, impacting its final quality. Concerning this problem, this work investigated the antimicrobial action of two organotin catalysts used in biodiesel production with four isolated microroorganisms (Bacillus pumilus, Pseudomonas aeruginosa, Pseudallescheria boydii, and Aureobasidium pullulans) and a pool of microorganisms (ASTM E1259 standard practice).

Use of digital images to count colonies of biodiesel deteriogenic microorganisms.

This work presents a novel, robust procedure for the semi-automated counting of colony-forming units of Bacillus pumilus (a bacterium) and Meyerozyma guilliermondii (a yeast) both isolated from diesel oil. The counting is performed from digital images of Petri dishes containing the samples by a developed Python code, and the images are acquired from a low-cost scanning apparatus. The counting algorithm is based on the similar morphological characteristics of the bacterium and the yeast colonies.

Development of a Pencil Drawn Paper-based Analytical Device to Detect Lysergic Acid Diethylamide (LSD)* †.

The need for agile and proper identification of drugs of abuse has encouraged the scientific community to improve and to develop new methodologies. The drug lysergic acid diethylamide (LSD) is still widely used due to its hallucinogenic effects. The use of voltammetric methods to analyze narcotics has increased in recent years, and the possibility of miniaturizing the electrochemical equipment allows these methods to be applied outside the laboratory; for example, in crime scenes.

Presence of antibiotic resistance genes and its association with antibiotic occurrence in Dilúvio River in southern Brazil.

It is known that antibiotics are widely used in human and veterinary medicine. In some countries the use is controlled, however few restrictions to their use are enforced in many countries. Antibiotics and their metabolites can reach the water bodies through sewage systems, especially in those countries with partial or absent wastewater treatment systems.

Evaluation of total polyphenol content of wines by means of voltammetric techniques: Cyclic voltammetry vs differential pulse voltammetry.

Taking advantage of the low oxidation potential of polyphenolic compounds, voltammetric techniques, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) are used rather indiscriminately. In this work, we report Total Polyphenols results (TPP) obtained by these two techniques from a set of nine samples of red and Tawny Port wine. The CV and DPV voltammograms display significant correlations with the physical-chemical parameters used to characterize red and Tawny Port wines, particularly with polyphenols.

Simulation of a surface spill of different diesel/biodiesel mixtures in an ultisol, using natural attenuation and bioaugmentation/biostimulation.

Accidents caused by leaks and/or spills on soils need to be addressed. Natural attenuation, biostimulation and bioaugmentation can be useful bioremediation strategies for decontamination processes in soils of diesel/biodiesel mixtures. The purpose of this study was to evaluate the degradation rate of the different fuels (B0, B20 and B100) in an ultisol under natural attenuation and biostimulation/bioaugmentation during 60 days of incubation in a controlled microcosm simulating a surface spill over soil.

Pseudallescheria boydii and Meyerozyma guilliermondii: behavior of deteriogenic fungi during simulated storage of diesel, biodiesel, and B10 blend in Brazil.

Due to their renewable and sustainable nature, biodiesel blends boost studies predicting their stability during storage. Besides chemical degradation, biodiesel is more susceptible to biodegradation due to its raw composition. The aim of this work was to evaluate the deteriogenic potential (growth and degradation) of Pseudallescheria boydii and Meyerozyma guilliermondii in degrading pure diesel (B0), pure biodiesel (B100), and a B10 blend in mineral medium during storage.

Comparative metagenomics reveals different hydrocarbon degradative abilities from enriched oil-drilling waste.

The oil drilling process generates large volumes of waste with inadequate treatments. Here, oil drilling waste (ODW) microbial communities demonstrate different hydrocarbon degradative abilities when exposed to distinct nutrient enrichments as revealed by comparative metagenomics. The ODW was enriched in Luria Broth (LBE) and Potato Dextrose (PDE) media to examine the structure and functional variations of microbial consortia.

Draft Genome Sequence of Bacillus sp. Strain UFRGS-B20, a Hydrocarbon Degrader.

sp. strain UFRGS-B20 was isolated in 2012 from Brazilian land-farming soil contaminated with petrochemical oily sludge. This strain was subjected to hydrocarbon biodegradation tests, showing degradation rates of up to 60%.

Metal resistance mechanisms in Gram-negative bacteria and their potential to remove Hg in the presence of other metals.

Contamination of the environment by heavy metals has been increasing in recent years due to industrial activities. Thus research involving microorganisms capable of surviving in multi-contaminated environments is extremely important. The objectives of the present study were to evaluate the removal of mercury alone and in the presence of cadmium, nickel and lead by four mercury-resistant microorganisms; estimate the removal of Cd, Ni and Pb; understand the mechanisms involved (reduction, siderophores, biofilms, biosorption and bioaccumulation) in the metal resistance of the isolate Pseudomonas sp.

Mercury (II) removal by resistant bacterial isolates and mercuric (II) reductase activity in a new strain of Pseudomonas sp. B50A.

This study aimed to isolate mercury resistant bacteria, determine the minimum inhibitory concentration for Hg, estimate mercury removal by selected isolates, explore the mer genes, and detect and characterize the activity of the enzyme mercuric (II) reductase produced by a new strain of Pseudomonas sp. B50A. The Hg removal capacity of the isolates was determined by incubating the isolates in Luria Bertani broth and the remaining mercury quantified by atomic absorption spectrophotometry.

Radical scavenging activity of antioxidants evaluated by means of electrogenerated HO radical.

A method is proposed and tested concerning the characterization of antioxidants by means of their reaction with electrogenerated HO radicals in galvanostatic assays with simultaneous O2 evolution, using a Pt anode fairly oxidized. The consumption of a set of species with antioxidant activity, ascorbic acid (AA), caffeic acid (CA), gallic acid (GA) and trolox (T), is described by a first order kinetics. The rate of the processes is limited by the kinetics of reaction with HO radicals and by the kinetics of charge transfer.

Simplified 2,4-dinitrophenylhydrazine spectrophotometric assay for quantification of carbonyls in oxidized proteins.

This work proposes a modification of the 2,4-dinitrophenylhydrazine (DNPH) spectrophotometric assay commonly used to evaluate the concentration of carbonyl groups in oxidized proteins. In this approach NaOH is added to the protein solution after the addition of DNPH, shifting the maximum absorbance wavelength of the derivatized protein from 370 to 450nm. This reduces the interference of DNPH and allows the direct quantification in the sample solution without the need for the precipitation, washing, and resuspension steps that are carried out in the traditional DNPH method.

Bioremediation assessment of diesel-biodiesel-contaminated soil using an alternative bioaugmentation strategy.

This study investigated the effectiveness of successive bioaugmentation, conventional bioaugmentation, and biostimulation of biodegradation of B10 in soil. In addition, the structure of the soil microbial community was assessed by polymerase chain reaction-denaturing gradient gel electrophoresis. The consortium was inoculated on the initial and the 11th day of incubation for successive bioaugmentation and only on the initial day for bioaugmentation and conventional bioaugmentation.

Direct electroanalytical method for alternative assessment of global antioxidant capacity using microchannel electrodes.

A new electroanalytical method for the characterization of global antioxidant capacity is proposed based on chronoamperometric responses monitored at microchannel band electrodes. This approach does not require any titrating species, biological elements, or precalibration curves. A thin-layer regime is established at the working electrode according to the geometry of the device and hydrodynamic flow rate.

Biosorption and bioreduction of copper from different copper compounds in aqueous solution.

High copper concentration is toxic for living organisms including humans. Biosorption is a bioremediation technique that can remove copper and other pollutants from aqueous medium and soils, consequently cleaning the environment. The aim of this study was, therefore, to investigate the influence of different copper compounds (Cu(II) as CuCl2; Cu(II) as CuSO4; and Cu(I) as CuCl) on copper bioreduction and biosorption using four copper-resistant bacteria isolated from the rhizosphere of two plants (Avena sativa and Plantago lanceolata) in aqueous matrix.

Isolation and characterization of bacteria from mercury contaminated sites in Rio Grande do Sul, Brazil, and assessment of methylmercury removal capability of a Pseudomonas putida V1 strain.

Methylmercury (MeHg) is one of the most dangerous heavy metal for living organisms that may be found in environment. Given the crescent industrialization of Brazil and considering that mercury is a residue of several industrial processes, there is an increasing need to encounter and develop remediation approaches of mercury contaminated sites. The aim of this study was to isolate and characterize methylmercury resistant bacteria from soils and sludge sewage from Rio Grande do Sul, Brazil.

Bioprospection and selection of bacteria isolated from environments contaminated with petrochemical residues for application in bioremediation.

The use of microorganisms with hydrocarbon degrading capability and biosurfactant producers have emerged as an alternative for sustainable treatment of environmental passives. In this study 45 bacteria were isolated from samples contaminated with petrochemical residues, from which 21 were obtained from Landfarming soil contaminated with oily sludge, 11 were obtained from petrochemical industry effluents and 13 were originated directly from oily sludge. The metabolization capability of different carbon sources, growth capacity and tolerance, biosurfactant production and enzymes detection were determined.

Capability of a selected bacterial consortium for degrading diesel/biodiesel blends (B20): enzyme and biosurfactant production.

The search for alternative sources of energy, such as biodiesel, has been stimulated, since this biofuel is highly susceptible for biodegradation and has low toxicity, thus, reducing the impact in ecosystems. The objective of this study was to select a bacterial consortium with potential for degrading diesel/biodiesel blends (B20) obtained from areas contaminated with hydrocarbons/esters. In order to evaluate the biodegrability of the blend, six enzyme assays were conducted: alkane hydroxylase, Catechol 1,2-dioxygenase, Catechol 2,3-dioxygenase, Protocatechol 3,4-dioxygenase, ρ-NPA hydrolysis (esterase), and release of fatty acids through titration (lipase), with estimative of total protein and biosurfactant production (surface tension measurement and emulsifying index E(24)).