scholarly journals LOW CONCENTRATION PHENOL DETECTION USING PSEUDOMONAS FLUORESCENS BIOFILM IMMOBILIZED ON SCREEN PRINTED CARBON ELECTRODE (SPCE)

2021 ◽  
Vol 56 (4) ◽  
pp. 1-6
Author(s):  
Dyah Iswantini ◽  
Rani Melati Sukma ◽  
Novik Nurhidayat ◽  
Ali Aulia Ghozali
Keyword(s):  
Pseudomonas Fluorescens ◽  
Ph Value ◽  
Limit Of Detection ◽  
Electrical Current ◽  
Bacterial Biofilm ◽  
Analytical Determination ◽  
Low Concentration ◽  
Low Concentrations ◽  
Biofilm Development ◽  
Related Compounds

A new method of phenol measurement based on cyclic voltammetry has been tried using Pseudomonas fluorescens biofilm as a bioreceptor. The research is aimed at developing a new measurement for detecting phenol and related compounds using bacterial biofilm. Therefore, it can be further developed for in situ phenol and related compounds monitoring. The trial evaluated several variables, such as optimum pH value during measurement and biofilm development time. Measurement was conducted at a relatively low concentration (1 ppb – 1 ppm). Based on the obtained data, the optimum measurement was at pH 8 and on the 6th day of developing bacterial biofilm that produced the maximal electrical current. The analytical determination revealed that the sensitivity was at 0.0433 mA/ppm with an R2 value of 0.9208. The apparent limit of detection value was extrapolated around 0.1 ppm; thus, it is suggested that biofilm had potency for measuring phenol at low concentrations. However, this trial needs improvements on biofilm stabilization for broader measured phenol concentrations.

scholarly journals Evaluation of Bacterial Biofilm as Biosensor for Detecting Phenol, Catechol, and 1,2-dihydroxynaphthalene

2021 ◽  
Vol 28 (4) ◽  
pp. 262-270
Author(s):  
Dyah Iswantini ◽  
Ali Aulia Ghozali ◽  
Cecep Kusmana ◽  
Novik Nurhidayat
Keyword(s):  
Water Quality ◽  
Pseudomonas Aeruginosa ◽  
Limit Of Detection ◽  
Phenol Degradation ◽  
Bacterial Biofilm ◽  
Polyaromatic Hydrocarbon ◽  
Bacterial Isolates ◽  
Physiological Properties ◽  
Hydrophobic Substances ◽  
Related Compounds

Monitoring of water quality from the presence of polyaromatic hydrocarbon (PAHs) compounds and its derivates are important for keeping the healthy aquatic environment. Some of those derivates are phenol and several related compounds sharing simmilar structures. This reseach aimed for the detection of those phenol and several similar compounds monitoring due to PAHs degradation. Three identified bacterial isolates of Pseudomonas aeruginosa, Staphylococcus sciuri, and Bacillus amyloliquifaciens were selected based on their phenol degradation characters. On physiological properties all three isolates were observed to degrade several hydrophobic substances such as for naphthalene and anthracene. Yet, genetic analysis indicated that the phenolic degradating oxygenase gene was detected only in the P. aeruginosa and S. sciuri. Applying those isolates for biofilm as biosensor showed a sufficient analytical performance such as their limit of detection between 0.1-0.5 μM.

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

scholarly journals The differential effect of synthetic growth substances and other compounds upon plant species II. Seed germination and early growth responses to some arylcarbamic esters and related compounds

1946 ◽  
Vol 133 (873) ◽  
pp. 480-485 ◽  
Keyword(s):  
Seed Germination ◽  
Differential Effect ◽  
Marked Effect ◽  
Early Growth ◽  
Growth Substances ◽  
Growth Responses ◽  
Low Concentrations ◽  
Dicotyledonous Plants ◽  
Related Compounds ◽  
Synthetic Growth

The preparation and biological examination of a number of arylcarbamic esters (arylurethanes) are described. The experiments demonstrate the marked effect of iso propyl phenylcarbamate and some related compounds in very low concentrations upon the germination and seedling growth of cereals. The absence of effect of the same compounds in similar concentrations upon some dicotyledonous plants is noted.

Direct radioimmunoassay of 6-sulfatoxymelatonin in plasma with use of an iodinated tracer

1991 ◽  
Vol 37 (4) ◽  
pp. 536-539 ◽  
Author(s):  
Catherine Harthé ◽  
Bruno Claustrat ◽  
Jocelyne Brun ◽  
Guy Chazot
Keyword(s):  
Plasma Sample ◽  
Limit Of Detection ◽  
Circadian Variation ◽  
Hepatic Metabolism ◽  
Pharmaceutical Formulations ◽  
Practical Application ◽  
Bovine Serum Albumin Conjugate ◽  
Preliminary Study ◽  
Related Compounds

Abstract We describe here a direct a radioimmunoassay (RIA) for the determination of 6-sulfatoxymelatonin (aMT6s) in plasma, with iodinated aMT6s as tracer. The aMT6s antiserum was raised in rabbit by immunization with a bovine serum albumin conjugate, giving negligible cross-reactivities for related compounds. The low limit of detection (15 pmol/L) allowed a direct assay that required only a 100-microL plasma sample. Dilutions of plasma and of synthetic aMT6s gave the same parallel response in the RIA. A preliminary study showed a circadian variation in healthy volunteers, with mean concentrations ranging from 52 (at 1600-2100 h) to 378 pmol/L (at 0400 h), whereas this rhythm was abolished in pinealomectomized patients. After administration of melatonin orally, or by infusion, the aMT6s concentrations in plasma concorded with previous data on aMT6s production and pharmacokinetics, with aMT6s being cleared from plasma more slowly than melatonin. This assay should have practical application in the development of new pharmaceutical formulations that minimize the hepatic metabolism of melatonin.

scholarly journals Low Concentrations of Chlorhexidine Inhibit the Formation and Structural Integrity of Enzyme-Treated Multispecies Oral Biofilms

2021 ◽  
Vol 12 ◽  
Author(s):  
Kay Andrin Gränicher ◽  
Lamprini Karygianni ◽  
Thomas Attin ◽  
Thomas Thurnheer
Keyword(s):  
Structural Integrity ◽  
Fluorescent Dyes ◽  
Combined Treatment ◽  
Extracellular Proteins ◽  
Laser Scanning Microscopy ◽  
Extracellular Dna ◽  
Anaerobic Growth ◽  
Low Concentration ◽  
Low Concentrations ◽  
Dental Hard Tissues

The self-produced matrix of biofilms, consisting of extracellular polymeric substances, plays an important role in biofilm adhesion to surfaces and the structural integrity of biofilms. In dentistry, biofilms cause multiple diseases such as caries, periodontitis, and pulpitis. Disruption of these biofilms adhering to dental hard tissues may pose a major challenge since biofilms show higher tolerance to antimicrobials and antibiotics than planktonic cells. In this study, the effect of low concentrations of chlorhexidine (CHX) on enzyme-treated multispecies oral biofilm was investigated in an in vitro model. Six-species biofilms were enzymatically treated by anaerobic growth in a medium containing DNase I and proteinase K. Biofilms were exposed to a low concentration of CHX at defined time points. After 64h, biofilms were either harvested and quantified by cultural analyses or stained for confocal laser scanning microscopy (CLSM) analyses using either Live/Dead kit or different fluorescent dyes. A mixture of YoPro1 and SYTOX™ Green, Fluorescent Brightener 28 (Calcofluor), and SYPRO™ Ruby Protein Gel Stain was used to stain total DNA, exopolysaccharides, and extracellular proteins, respectively. Extracellular DNA (eDNA) was visualized via an indirect immunofluorescence assay (Mouse anti-DNA IgG, Goat anti-Mouse IgG, Streptavidin-Cy3). Overall, the total colony-forming units significantly decreased after combined treatment with a low concentration of CHX and enzymes compared to the group treated with CHX alone (p&lt;0.001). These findings also apply to five species individually (Streptococcus mutans, Streptococcus oralis, Actinomyces oris, Veillonella dispar, and Candida albicans) occurring in the biofilms, with Fusobacterium nucleatum being the only exception. Furthermore, CLSM images showed less dense biofilms and a reduction in cell numbers after combined treatment compared to the group without enzymes. The combination of enzymes capable of disturbing the matrix integrity with antimicrobial agents thus appears to be a promising approach for biofilm disruption and killing.

scholarly journals Сitric acid influence on electroreduction processes in low concentrated Cu(NO3)2 solutions

2017 ◽  
Vol 5 (2) ◽  
pp. 136-143
Author(s):  
Alla Pravda ◽  
Vasil Larin
Keyword(s):  
Citric Acid ◽  
Ph Value ◽  
Reduction Reaction ◽  
Copper Electrodeposition ◽  
Nitrate Ions ◽  
Low Concentrations ◽  
Physico Chemical ◽  
Influence Of Ph ◽  
Kinetics Of ◽  
Cathode Reduction

Physico-chemical regularities citric acid influence on processes of copper and nitrate-ions reduction in low concentrated nitrate solutions were established. An influence of pH value on inhibitor action of low concentrations of the additive according to cathode reduction reaction of nitrate-ions, on kinetics of copper electrodeposition, on structure of the precipitates obtained was shown. Polarization measurements show us changes of copper electrodeposition at introduction of citric acid in Cu(NO3)2 solution. By the methods of traced elements and extraction into aqueous phase the reversible inclusion complexes into electrolytic copper, was established that proves participation of complexes in cathode process.

The autotrophic nutrition of symbiotic marine coelenterates with special reference to hermatypic corals. I. Movement of photosynthetic products between the symbionts

1971 ◽  
Vol 178 (1050) ◽  
pp. 111-129 ◽  
Keyword(s):  
Amino Acids ◽  
Organic Nitrogen ◽  
Sea Water ◽  
Nitrogen Compounds ◽  
Organic Substances ◽  
Low Concentrations ◽  
Steady Rate ◽  
Hermatypic Corals ◽  
Photosynthetic Products ◽  
Related Compounds

When symbiotic coelenterates, especially hermatypic corals, were incubated in the light in sea water containing NaH 14 CO 3 , small quantities of fixed 14 C were released from the tissues at a steady rate over 4 h. The rate of release was greatly increased in the presence of glycerol, glucose and alanine; the additional 14 C released was in the same substance as that added to the medium. The following related compounds had little or no effect on 14 C release : ethylene glycol, sorbose, fructose, glucosamine, glycine, proline, serine and glutamic acid. Such results have been previously reported in other symbiotic systems, and the substances causing the specific release of fixed 14 C are believed to be those which move from the autotrophic to the heterotrophic symbiont. This belief is supported here by previous observations that glycerol, glucose and alanine are among the most important organic substances released by freshly isolated zooxanthellae. Ammonium chloride increased the amount of fixed 14 C released by corals into alanine media, possibly due to conversion of ammonia to amino acids by zooxanthellae. Appreciable release of 14 C fixed in the dark also occurred into alanine solutions. These results suggest possible roles of zooxanthellae in supplying organic nitrogen compounds to the host cell at night as well as during the day. The involvement of zooxanthellae in ‘recycling’ nitrogen compounds within the association may help to explain the success of corals in seas poor in nutrients. There was substantial utilization of external glycerol and glucose when supplied at either high or low concentrations. Corals may well be able to utilize some of the small amounts of organic matter dissolved in sea water in the natural environment.

scholarly journals Options and Limitations in Clinical Investigation of Bacterial Biofilms

2018 ◽  
Vol 31 (3) ◽  
Author(s):  
Maria Magana ◽  
Christina Sereti ◽  
Anastasios Ioannidis ◽  
Courtney A. Mitchell ◽  
Anthony R. Ball ◽  
...  
Keyword(s):  
Clinical Investigation ◽  
Bacterial Biofilm ◽  
Clinical Settings ◽  
Microbial Composition ◽  
The Past ◽  
Methodological Research ◽  
Current Trends ◽  
Literature Searches ◽  
Biofilm Development ◽  
Multispecies Biofilms

SUMMARYBacteria can form single- and multispecies biofilms exhibiting diverse features based upon the microbial composition of their community and microenvironment. The study of bacterial biofilm development has received great interest in the past 20 years and is motivated by the elegant complexity characteristic of these multicellular communities and their role in infectious diseases. Biofilms can thrive on virtually any surface and can be beneficial or detrimental based upon the community's interplay and the surface. Advances in the understanding of structural and functional variations and the roles that biofilms play in disease and host-pathogen interactions have been addressed through comprehensive literature searches. In this review article, a synopsis of the methodological landscape of biofilm analysis is provided, including an evaluation of the current trends in methodological research. We deem this worthwhile because a keyword-oriented bibliographical search reveals that less than 5% of the biofilm literature is devoted to methodology. In this report, we (i) summarize current methodologies for biofilm characterization, monitoring, and quantification; (ii) discuss advances in the discovery of effective imaging and sensing tools and modalities; (iii) provide an overview of tailored animal models that assess features of biofilm infections; and (iv) make recommendations defining the most appropriate methodological tools for clinical settings.

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