Terra rossa as the substrate for biological phosphate removal from wastewater

Clay Minerals ◽  
2013 ◽  
Vol 48 (5) ◽  
pp. 725-738 ◽  
Author(s):  
G. Durn ◽  
J. Hrenovic ◽  
L. Sekovanic
Keyword(s):  
Phosphate Removal ◽  
Bacterial Cells ◽  
Total Iron Content ◽  
Terra Rossa ◽  
Acinetobacter Junii ◽  
Immobilized Bacteria ◽  
Support Materials ◽  
Three Samples ◽  
Key Factor ◽  
Extractable Iron

AbstractThree samples of terra rossa were shown to be efficient adsorbents of phosphate [P(V)] from wastewater and removed 29.9–32.6% of P(V). The total iron content in terra rossa was the key factor which determined the P(V) removal from wastewater. The original samples of terra rossa were effective support materials for the immobilization of metabolically active P(V)-accumulating bacteriaAcinetobacter junii(0.56–2.47×1010CFU g–1). The removal of oxalate-extractable iron from original sample of terra rossa increased the number of immobilized bacteria to 1.34×10–11CFU g–1, which is the largest number of immobilized bacteria reported in the literature so far. In reactors containing theA. juniiand terra rossa P(V) was removed from wastewater by simultaneous adsorption onto terra rossa and accumulation inside bacterial cells, resulting in 40.5–62.5% of P(V) removal. Terra rossa is a promising substrate for biological P(V) removal from wastewater, acting both as adsorbent of P(V) and carrier of P(V)-accumulating bacteria.

Attachment of oral bacteria to titanium surfaces: An SEM study

1994 ◽  
Vol 52 ◽  
pp. 468-469
Author(s):  
J. E. Laffoon ◽  
R. L. Anderson ◽  
J. C. Keller ◽  
C. D. Wu-Yuan
Keyword(s):  
Technical Problem ◽  
Titanium Implant ◽  
Oral Bacteria ◽  
Bacterial Cells ◽  
Thin Sections ◽  
Surface Ultrastructure ◽  
Sem Study ◽  
Key Factor ◽  
Titanium Surfaces

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).

scholarly journals Recent Development of Rapid Antimicrobial Susceptibility Testing Methods through Metabolic Profiling of Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 311
Author(s):  
Chen Chen ◽  
Weili Hong
Keyword(s):  
Antimicrobial Susceptibility ◽  
Metabolic Profiling ◽  
Bacterial Infections ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Metabolism ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Inappropriate Use ◽  
Key Factor

Due to the inappropriate use and overuse of antibiotics, the emergence and spread of antibiotic-resistant bacteria are increasing and have become a major threat to human health. A key factor in the treatment of bacterial infections and slowing down the emergence of antibiotic resistance is to perform antimicrobial susceptibility testing (AST) of infecting bacteria rapidly to prescribe appropriate drugs and reduce the use of broad-spectrum antibiotics. Current phenotypic AST methods based on the detection of bacterial growth are generally reliable but are too slow. There is an urgent need for new methods that can perform AST rapidly. Bacterial metabolism is a fast process, as bacterial cells double about every 20 to 30 min for fast-growing species. Moreover, bacterial metabolism has shown to be related to drug resistance, so a comparison of differences in microbial metabolic processes in the presence or absence of antimicrobials provides an alternative approach to traditional culture for faster AST. In this review, we summarize recent developments in rapid AST methods through metabolic profiling of bacteria under antibiotic treatment.

Immobilization of Phenol Degrader Pseudomonas sp In Repeated Batch Culture Using Bioceramic and Sponge as Support Materials

2012 ◽  
Author(s):  
Mailin Misson ◽  
Firdausi Razali
Keyword(s):  
Batch Culture ◽  
Packed Column ◽  
Tolerance Limit ◽  
Phenol Removal ◽  
Bacterial Cells ◽  
Pseudomonas Sp ◽  
Support Materials ◽  
Removal Capacity ◽  
Repeated Batch Culture ◽  
Repeated Batch

Prestasi dua jenis penyokong yang lengai iaitu bioseramik dan span untuk menyekat gerak bakteria pengurai fenol Pseudomonas sp di dalam turus terpadat telah dikaji dalam kultur kelompok berulang. Sebelum ini, kajian kami menunjukkan bahawa penyekat gerakan telah menggandakan had daya tahan mikrob terhadap kepekatan fenol dari 1000 ppm (dalam kultur ampaian) ke 2000 ppm. Pada isipadu yang sama, bioseramik berupaya memerangkap sel bakteria 1.8 kali lebih banyak daripada span. Oleh itu, ia berupaya mengurai 100% fenol yang berkepekatan 1000 ppm dalam masa 24 jam pada kadar alir suapan 2.5 ml/min, dan mengulangi prestasi yang sama dalam enam kelompok berturut–turut seterusnya. Namun demikian, sel yang terperangkap dalam span hanya berupaya mengurai 90% fenol dalam lima kelompok. Walaupun prestasinya lebih rendah, penggunaan span untuk memerangkap sel dalam skala yang besar memberikan beberapa kebaikan seperti ringan dan senang diperoleh pada harga yang lebih murah. Kata kunci: Tersekat gerak, fenol, Pseudomonas sp, bioseramik, kultur kelompok berulang The performance of two types of inert support, namely bioceramic and sponge to immobilize a locally isolated phenol degrader Pseudomonas sp. in a packed column was investigated in repeated batch culture. Prior to this, our study indicated that immobilization had doubled the tolerance limit of the cells towards phenol from 1000 ppm (in the suspended culture), to 2000 ppm. For the same volume, the bioceramic managed to trap bacterial cells 1.8 times greater than the sponge did. As a result, it was able to remove 100% of 1000 ppm 600–ml phenol fed at a rate of 2.5 ml/min within 24 hours, and the phenol removal capacity was sustained in the next six consecutive batches. Cells entrapped in sponge however, managed to remove around 90% phenol in five batches. Despite lower performance, at large scales, the use of sponge for cell entrapment offers some merits such as lightness, and easily available at cheaper cost. Key words: Immobilization, phenol, Pseudomonas sp, bioceramic, repeated batch

scholarly journals Recovery and utilization of phosphorus from fruit and vegetable wastewater

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu Qin ◽  
Huili Li ◽  
Shuanglong Ma ◽  
Kai Li ◽  
Xiaohan Zhang ◽  
...  
Keyword(s):  
Phosphate Removal ◽  
Water Bodies ◽  
Municipal Sewage ◽  
Fruit And Vegetable ◽  
Phosphorus Adsorption ◽  
Surface Precipitation ◽  
Phosphorus Containing ◽  
Key Factor ◽  
Promote Plant Growth

AbstractExcessive discharge of phosphorus into the water bodies is the key factor to cause eutrophication. The fruit and vegetable wastewater contains large amounts of phosphorus, and it may be directly discharged into water bodies, which has a great burden on the municipal sewage pipe network. Therefore, coagulation was used to remove phosphorus, recovered the phosphorus from the wastewater into the precipitate, and then the precipitate was pyrolyzed as an efficient adsorbent for phosphate removal. By comparing the adsorption effects of adsorbents (XT-300, XT-400, and XT-500) with pyrolysis temperatures of 300 °C, 400 °C, and 500 °C on phosphate in actual phosphorus-containing wastewater and simulated phosphorus-containing wastewater at different adsorbent dosage (4 g/L, 7 g/L, and 10 g/L), it was found that XT-300 had the best performance of adsorption, and the adsorption of phosphate was endothermic and obeyed the Langmuir isotherms and Elovich kinetics. The influence of pH, coexisting anions, and the structure of XT-300 revealed that the removal of phosphate was associated with electrostatic attraction, pore filling, but could not be determined whether it was related to surface precipitation. This study provides a way and method for the recovery and utilization of phosphorus in fruit and vegetable wastewater and proves that the synthetic adsorbent was an efficient phosphorus adsorbent. In the long term, we can try to use the adsorbent after phosphorus adsorption to promote plant growth in agricultural systems.

scholarly journals Uptake of Ozenoxacin and Other Quinolones in Gram-Positive Bacteria

2021 ◽  
Vol 22 (24) ◽  
pp. 13363
Author(s):  
Yuly López ◽  
Laura Muñoz ◽  
Domingo Gargallo-Viola ◽  
Rafael Cantón ◽  
Jordi Vila ◽  
...  
Keyword(s):  
Bacterial Cell ◽  
Dry Weight ◽  
Bacterial Cells ◽  
Topoisomerase Iv ◽  
Gram Positive Bacteria ◽  
Agar Disc ◽  
Key Factor ◽  
Ic50 Values ◽  
Important Challenge

The big problem of antimicrobial resistance is that it requires great efforts in the design of improved drugs which can quickly reach their target of action. Studies of antibiotic uptake and interaction with their target it is a key factor in this important challenge. We investigated the accumulation of ozenoxacin (OZN), moxifloxacin (MOX), levofloxacin (LVX), and ciprofloxacin (CIP) into the bacterial cells of 5 species, including Staphylococcus aureus (SA4-149), Staphylococcus epidermidis (SEP7602), Streptococcus pyogenes (SPY165), Streptococcus agalactiae (SAG146), and Enterococcus faecium (EF897) previously characterized.The concentration of quinolone uptake was estimated by agar disc-diffusion bioassay. Furthermore, we determined the inhibitory concentrations 50 (IC50) of OZN, MOX, LVX, and CIP against type II topoisomerases from S. aureus.The accumulation of OZN inside the bacterial cell was superior in comparison to MOX, LVX, and CIP in all tested species. The accumulation of OZN inside the bacterial cell was superior in comparison to MOX, LVX, and CIP in all tested species. The rapid penetration of OZN into the cell was reflected during the first minute of exposure with antibiotic values between 190 and 447 ng/mg (dry weight) of bacteria in all strains. Moreover, OZN showed the greatest inhibitory activity among the quinolones tested for both DNA gyrase and topoisomerase IV isolated from S. aureus with IC50 values of 10 and 0.5 mg/L, respectively. OZN intracellular concentration was significantly higher than that of MOX, LVX and CIP. All of these features may explain the higher in vitro activity of OZN compared to the other tested quinolones.

scholarly journals Rapid Detection of New Delhi Metallo-β-Lactamase Gene Using Recombinase-Aided Amplification Directly on Clinical Samples From Children

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanling Feng ◽  
Guanhua Xue ◽  
Junxia Feng ◽  
Chao Yan ◽  
Jinghua Cui ◽  
...  
Keyword(s):  
Klebsiella Oxytoca ◽  
Multi Drug Resistance ◽  
Clinical Samples ◽  
Resistant Bacteria ◽  
New Delhi ◽  
Analytical Sensitivity ◽  
Acinetobacter Junii ◽  
Carbapenem Resistant ◽  
Three Samples ◽  
Lactamase Gene

New Delhi metallo-β-lactamase, a metallo-β-lactamase carbapenemase type, mediates resistance to most β-lactam antibiotics including penicillins, cephalosporins, and carbapenems. Therefore, it is important to detect blaNDM genes in children’s clinical samples as quickly as possible and analyze their characteristics. Here, a recombinase-aided amplification (RAA) assay, which operates in a single one-step reaction tube at 39°C in 5−15 min, was established to target blaNDM genes in children’s clinical samples. The analytical sensitivity of the RAA assay was 20 copies, and the various bacterial types without blaNDM genes did not amplify. This method was used to detect blaNDM genes in 112 children’s stool samples, 10 of which were tested positive by both RAA and standard PCR. To further investigate the characteristics of carbapenem-resistant bacteria carrying blaNDM in children, 15 carbapenem-resistant bacteria (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Citrobacter freundii, Klebsiella oxytoca, Acinetobacter junii, and Proteus mirabilis) were isolated from the 10 samples. Notably, more than one bacterial type was isolated from three samples. Most of these isolates were resistant to cephalosporins, cefoperazone-sulbactam, piperacillin-tazobactam, ticarcillin-clavulanic acid, aztreonam, co-trimoxazole, and carbapenems. blaNDM–1 and blaNDM–5 were the two main types in these samples. These data show that the RAA assay has potential to be a sensitive and rapid blaNDM gene screening test for clinical samples. The common existence of blaNDM and multi-drug resistance genes presents major challenges for pediatric treatment.

scholarly journals Expression ofPseudomonas aeruginosaAntibiotic Resistance Genes Varies Greatly during Infections in Cystic Fibrosis Patients

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Lois W. Martin ◽  
Cynthia L. Robson ◽  
Annabelle M. Watts ◽  
Andrew R. Gray ◽  
Claire E. Wainwright ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cystic Fibrosis ◽  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Antibiotic Resistance Gene ◽  
Resistance Mechanisms ◽  
Laboratory Culture ◽  
Bacterial Cells ◽  
Content Type ◽  
Key Factor

ABSTRACTThe lungs of individuals with cystic fibrosis (CF) become chronically infected withPseudomonas aeruginosathat is difficult to eradicate by antibiotic treatment. Two keyP. aeruginosaantibiotic resistance mechanisms are the AmpC β-lactamase that degrades β-lactam antibiotics and MexXYOprM, a three-protein efflux pump that expels aminoglycoside antibiotics from the bacterial cells. Levels of antibiotic resistance gene expression are likely to be a key factor in antibiotic resistance but have not been determined during infection. The aims of this research were to investigate the expression of theampCandmexXgenes during infection in patients with CF and in bacteria isolated from the same patients and grown under laboratory conditions.P. aeruginosaisolates from 36 CF patients were grown in laboratory culture and gene expression measured by reverse transcription-quantitative PCR (RT-qPCR). The expression ofampCvaried over 20,000-fold and that ofmexXover 2,000-fold between isolates. The median expression levels of both genes were increased by the presence of subinhibitory concentrations of antibiotics. To measureP. aeruginosagene expression during infection, we carried out RT-qPCR using RNA extracted from fresh sputum samples obtained from 31 patients. The expression ofampCvaried over 4,000-fold, whilemexXexpression varied over 100-fold, between patients. Despite these wide variations, median levels of expression ofampCin bacteria in sputum were similar to those in laboratory-grown bacteria. The expression ofmexXwas higher in sputum than in laboratory-grown bacteria. Overall, our data demonstrate that genes that contribute to antibiotic resistance can be highly expressed in patients, but there is extensive isolate-to-isolate and patient-to-patient variation.

Iron Chemical Analysis of Spodosols to Date Last Pleistocene-Holocene. The Example of the Italian Central Alps.

2020 ◽  
Author(s):  
Alessandro Longhi ◽  
Mauro Guglielmin
Keyword(s):  
Iron Content ◽  
Soil Formation ◽  
Total Iron ◽  
Physical Analysis ◽  
Distribution Analysis ◽  
Central Alps ◽  
Total Iron Content ◽  
The Difference ◽  
Iron Fraction ◽  
Extractable Iron

<p>The deglaciation of the Italian Central Alps is still discussed and not well known, especially when we consider the Late Pleistocene-Early Holocene. This study will use different fraction of the iron content of paleo-spodosols to date the time of the deglaciation of three areas in the Central Italian Alps (Gavia, Stelvio and Val Viola). Relying on a first soil distribution analysis and on geomorphological evidences, we opened and described 24 soil pits and from each A and B horizon we collected at least 1 kg of sample to do some basic soil physical analysis: granulometry, water content, pH and loss on ignition. The oxalate extractable iron fraction and the dithionite extractable iron fraction have been determined with standard lab procedures, the total iron content has been determined using a SEM/EDX analysis. We calculated the Iron Crystallinity Ratio, defined as the difference between the dithionite extractable iron fraction and the oxalate extractable iron fraction, normalized on the total iron content. The Iron Crystallinity Ratio gives us a relative age of the soil formation: using data from radiocarbon dating and from cosmogenic dating, we calibrated the Iron Crystallinity Ratio with absolute ages. With the obtained functions, which showed a good fitting, we calculated ages between 15809 years and 5490 years in the Gavia area, between 11760 years and 7237 years in the Stelvio area and between 14668 years and 7096 years in the Val Viola area.</p>

Microbial Aspects in Corrosion Studies of Stainless Steels

2011 ◽  
Vol 183 ◽  
pp. 117-124
Author(s):  
Joanna Michalska
Keyword(s):  
Bacterial Cells ◽  
Hydrogen Damage ◽  
Materials Engineering ◽  
Research Areas ◽  
Microbially Influenced Corrosion ◽  
Corrosion Studies ◽  
Adequate Understanding ◽  
Key Factor ◽  
Complex Boundary ◽  
Microbial Risks

Microbially influenced corrosion (MIC) has been focusing increasing attention from different research areas in the last years, as an answer to the demand of wide variety of industries and degradation cases. The difficulty in reaching an adequate understanding of corrosion processes induced by microorganisms has result in cross-fertilization of ideas between researchers from different disciplines like microbiology, electrochemistry, metallurgy and materials engineering. Different MIC mechanisms can be simultaneously or alternately occuring on various materials, where a complex boundary layer of corrosion products, bacterial cells and other environmental factors are present on the surface. The paper discusses new aspects of MIC mechanisms induced by sulphate reducing bacteria species, taking into consideration modern techniques and new approaches in the study. Practical cases concerning microbial risks, failures illustrate the complexity of this phenomena: from local corrosion problems through stress corrosion cracking and hydrogen damage. The role of microstructure and chemical composition of materials is also highlited as a key factor in microbial damaging. In addition to this, the principal morphologies of attack and cracking are described.

Effect of piperacillin on morphology and viability of gram-negative bacteria

1984 ◽  
Vol 42 ◽  
pp. 218-219
Author(s):  
R. H. Liss
Keyword(s):  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Drug Binding ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Drug Induced ◽  
Penicillin Binding Proteins ◽  
Lactam Antibiotic ◽  
Drug Free ◽  
Tube Dilution

Piperacillip (PIP) is b-[D(-)-α-(4-ethy1-2,3-dioxo-l-piperzinylcar-bonylamino)-α-phenylacetamido]-penicillanate. The broad spectrum semisynthetic β-lactam antibiotic is believed to effect bactericidal activity through its affinity for penicillin-binding proteins (PBPs), enzymes on the bacterial cytoplasmic membrane that control elongation and septation during cell growth and division. The purpose of this study was to correlate penetration and binding of 14C-PIP in bacterial cells with drug-induced lethal changes assessed by microscopic, microbiologic and biochemical methods.The bacteria used were clinical isolates of Escherichia coli and Pseudomonas aeruginosa (Figure 1). Sensitivity to the drug was determined by serial tube dilution in Trypticase Soy Broth (BBL) at an inoculum of 104 organisms/ml; the minimum inhibitory concentration of piperacillin for both bacteria was 1 μg/ml. To assess drug binding to PBPs, the bacteria were incubated with 14C-PIP (5 μg/0.09 μCi/ml); controls, in drug-free medium.

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