Pyrolysis of bacterial polyalkanoates

1981 ◽  
Vol 59 (15) ◽  
pp. 2306-2313 ◽  
Author(s):  
Hiromichi Morikawa ◽  
Robert H. Marchessault
Keyword(s):  
Crotonic Acid ◽  
Bacterial Cells ◽  
Nmr Analysis ◽  
Pyrolysis Products ◽  
Bacterial Cultures ◽  
Pyrolysis Method ◽  
Bacterial Polyesters

Pyrolysis products from bacterial polyesters, poly-β-hydroxybutyrate (PHB), and from a heteropolyester (β-hydroxyvalerate and β-hydroxybutyrate) were identified. Different physical forms of PHB were studied: PHB purified by dissolution in chloroform, native granules of PHB, and PHB in bacterial cells. The products were characterized by gc, ms, and nmr analysis. The yield of crotonic acid obtained by the pyrolysis of purified PHB was 60 to 65%. Pyrolysis of PHB native granules yielded crotonic acid as well as oligomers of PHB with a terminal crotonate. Upon direct pyrolysis of dry bacterial cells, the yield of crotonic acid was 20 to 25% of the PHB in the cells. From the heteropolymer, 2-pentenoic acid and terminally unsaturated oligomers of polyhydroxyvalerate were obtained. The usefulness of the pyrolysis method for obtaining vinyl compounds from bacterial cultures containing polyalkanoates is discussed.

scholarly journals A RADAR-Based Assay to Isolate Covalent DNA Complexes in Bacteria

Antibiotics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
Katie Aldred ◽  
Adeline Payne ◽  
Olivia Voegerl
Keyword(s):  
Dna Adduct ◽  
Bacterial Cells ◽  
Topoisomerase Iv ◽  
Bacterial Cultures ◽  
Cellular Context ◽  
Specialized Equipment ◽  
Cultured Human Cells ◽  
Cleavage Complex ◽  
Dna Precipitation ◽  
Mechanical Lysis

Quinolone antibacterials target the type II topoisomerases gyrase and topoisomerase IV and kill bacterial cells by converting these essential enzymes into cellular poisons. Although much is known regarding the interactions between these drugs and enzymes in purified systems, much less is known regarding their interactions in the cellular context due to the lack of a widely accessible assay that does not require expensive, specialized equipment. Thus, we developed an assay, based on the “rapid approach to DNA adduct recovery,” or RADAR, assay that is used with cultured human cells, to measure cleavage complex levels induced by treating bacterial cultures with the quinolone ciprofloxacin. Many chemical and mechanical lysis conditions and DNA precipitation conditions were tested, and the method involving sonication in denaturing conditions followed by precipitation of DNA via addition of a half volume of ethanol provided the most consistent results. This assay can be used to complement results obtained with purified enzymes to expand our understanding of quinolone mechanism of action and to test the activity of newly developed topoisomerase-targeted compounds. In addition, the bacterial RADAR assay can be used in other contexts, as any proteins covalently complexed to DNA should be trapped on and isolated with the DNA, allowing them to then be quantified.

scholarly journals Inhibition of hemolytic activity of Streptococcus pyogenes in mechanisms of antibacterial action of zinc ions

2019 ◽  
pp. 16-23
Author(s):  
S. B. Cheknev ◽  
E. I. Vostrova ◽  
M. A. Sarycheva ◽  
A. V. Vostrov
Keyword(s):  
Growth Inhibition ◽  
Streptococcus Pyogenes ◽  
Hemolytic Activity ◽  
Inhibitory Action ◽  
Bacterial Culture ◽  
Copper Ions ◽  
Zinc Ions ◽  
Bacterial Cells ◽  
Bacterial Cultures ◽  
Culture Growth

Aim. The work was performed with the purpose to study a hemolytic activity in the culture of S.pyogenes under the inhibitory action of millimolar concentrations of zinc ions.Materials and methods. Suspensions of S.pyogenes bacteria which contained 108 CFU/ml were sown by the lawns into the standard Petri dishes coated with the supplemented Blood Nutrient Agar. 30 min later the salt solutions of zinc or copper which contained the metals at the concentrations ranged between 5 x 10-3 M to 5 x 10-1 M were added by the 5 μl drops on the surfaces of the lawns with use of 36-channel stamp replicator. Then the dishes with bacterial cultures were incubated for 24 hrs at 37°C followed by measuring diameter of the area of culture growth inhibition and of the area of inhibition of hemolysis. The study was performed with use of controls towards measuring the state of bacterial cells obtained from different zones of the areas.Results. In presence of the zinc ions concentrations ranged between 50 to 500 mM the area of the growth inhibition of S.pyogenes was surrounded on the lawn of the bacterial culture by the area of the inhibition of hemolysis where the growth inhibition of S.pyogenes was not registered. Copper ions did not form such an area of the hemolysis inhibition.Conclusion. Inhibitory action of zinc ions on the hemolytic S.pyogenes activity in the culture seems to be specific and reversible, and is discussed in a context of the antivirulent zinc ions properties.

scholarly journals Pengaruh Jumlah Inokulum Sel Inang Bakteri E.coli BL21 (DE3) pLysS dan Waktu Overekspresi pada Produksi Protein Rekombinan Fim-C Salmonella typhi

2018 ◽  
Vol 4 (2) ◽  
pp. 98-106
Author(s):  
Muktiningsih - Nurjayadi ◽  
Izzatul Ilma Chairinnisa ◽  
Geta Putri Mentari ◽  
Dudi Hardianto ◽  
Asri Sulfianti ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Large Scale ◽  
Salmonella Typhi ◽  
Cell Number ◽  
Bacterial Cells ◽  
Typhoid Vaccine ◽  
Over Expression ◽  
Bacterial Cultures ◽  
Sds Page

Recombinant protein Fim-C S.typhi is a potential protein that can be used as an alternative typhoid vaccine and produced on a large scale. However, before entering into a large-scale stage, laboratory optimum data on the factors that affect the production process of Fim-C Salmonella typhi proteins are required. This study aims to obtain information regarding the effect of host cell number E.coli BL21 (DE3) pLysS and overexpression time on production of recombinant protein Fim-C Salmonella typhi as the basis for developing candidate of typhoid vaccine. The optimization process of overexpression was done by adding 0.5 mM IPTG (Isopropyl-β-D-thiogalactopyranoside) inducer into bacterial cultures of 2%, 4%, and 6% with 4, 5, and 6 hours over expression. The measurement of the concentration of Fim-C recombinant protein extracted samples were done by a spectrophotometric method used BCA Kit Assay Thermo ScientificTM with wavelength 590nm. The characterization of those protein extracts was performed using SDS-PAGE method. The results from the study concluded that the number of 4% E.coli bacterial cells and four-hour overexpression time are the optimum condition of Fim- C Salmonella typhi characterized by the presence of high-intensity bands at ± 31 kDa.  

Alternaria toxins of the alternariol type are not metabolised by human faecal microbiota

2016 ◽  
Vol 9 (1) ◽  
pp. 41-50 ◽  
Author(s):  
A. Lemke ◽  
B. Burkhardt ◽  
D. Bunzel ◽  
E. Pfeiffer ◽  
M. Metzler ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Brain Heart Infusion ◽  
Bacterial Cells ◽  
Faecal Microbiota ◽  
Anaerobic Conditions ◽  
Bacterial Cultures ◽  
Alternaria Toxins ◽  
Heat Treated ◽  
Human Volunteers ◽  
Pure Bacterial Cultures

The metabolism of the Alternaria toxins alternariol (AOH), alternariol-9-O-methyl ether (AME) and altenuene (ALT) by the microbiota present in faeces from three human volunteers was studied. Faecal cultures were prepared as a 5% faeces suspension in brain-heart infusion broth and incubated with 50 μM of the toxins under anaerobic conditions for 72 h at 37 °C. The metabolism of AOH was also studied in pure bacterial cultures with either Escherichia coli DH5α or Lactobacillus plantarum BFE 5092 for 72 h at 37 °C. The three parent toxins were stable in uninoculated, heat-treated medium over a 72 h incubation period with a recovery of more than 90%. As a control for the activity of the faecal microbiota, the isoflavone daidzein was incubated with the faecal cultures and was transformed to its expected metabolites. In contrast, no metabolites of AOH, AME and ALT could be detected in the faecal cultures from the same volunteers, indicating that the gut microbiota was not capable of metabolising these substances. The Alternaria toxins could be shown to be at least partially bound to bacterial cells in a non-covalent manner, which may serve as a mechanism for their removal from the gut.

Formulation of a Multifunctional Biopreparations for Phytoremediation of Oil-Contaminated Soils: from Laboratory to Pilot-Industrial Technology

2018 ◽  
Vol 22 (7) ◽  
pp. 44-49
Author(s):  
V.S. Muratov ◽  
K.A. Kydralieva ◽  
Yu.A. Nishkevich ◽  
I.A. Kozlov ◽  
V.A. Terekhova
Keyword(s):  
Contaminated Soils ◽  
Bacterial Cells ◽  
Optimal Temperature ◽  
Drying Method ◽  
Centrifugal Field ◽  
Bacterial Cultures ◽  
Operational Characteristics ◽  
Liquid Preparation ◽  
Contact Drying ◽  
Microbial Preparation

A formulation method for biopreparations stimulating phytoremediation of oil-contaminated soils based on rhizobacteria was proposed. Technology involves the cultivation of bacterial cultures Bacillus RB15 and Pseudomonas RB43 in a liquid nutrient medium, followed by concentration the biomass by centrifugation and drying the finished product by contact drying. The optimal temperature (23–30 °C) and the duration of the process (three days) were determined at the stage of preparation of the liquid preparation (cultural liquor CL rhizobacteria). A comparative analysis of the results of the concentration of CL using various methods – vacuum evaporation, ultrafitration and centrifugation showed that the application of the method of concentrating biomass in a centrifugal field is most suitable both for technological and operational characteristics. То obtain the finished dry form of preparation, the contact drying method is recommended. The parameter of preservation of the viability of RB cells was used as the main controlled parameter at all technological stages of production. To obtain the finished commodity form of the microbial preparation, it is proposed to use a complex sorbent as a filler in the standardization of the finished product, the moisture sorbent in contact drying, and the carrier for immobilization of bacterial cells. To promote the technology of biopreparations in practice, a pilot experimental industrial production and technological scheme of production were elaborated.

scholarly journals Delivery of Molecules to Cancer Cells Using Liposomes from Bacterial Cultures

2008 ◽  
Vol 8 (5) ◽  
pp. 2328-2333
Author(s):  
Vibhuti Gupta ◽  
Roohi Gupta ◽  
Rahul Grover ◽  
Rajat Khanna ◽  
Vijeta Jangra ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Soft Materials ◽  
Reaction Engineering ◽  
Raw Material ◽  
Model Systems ◽  
Bacterial Cells ◽  
E Coli ◽  
Bacterial Cultures ◽  
Delivery Vehicles ◽  
Robust Procedures

Liposomes have a variety of applications as model systems to study enclosed biological membranes, as delivery vehicles for a variety of drugs and as micro- and nano-reactors, amongst others. However, preparation of liposomes requires use of expensive raw material (synthetic lipids) from specialized commercial suppliers, and ability to make reproducible preparations remains a specialized art till date. In this work, we prepared liposomes using natural lipids extracted from the bacteria Escherichia coli (E. coli), which are extremely economical compared to the synthetic lipids. We demonstrate robust procedures for convenient and reproducible preparations of 200–300 nm diameter liposomes from bacterial cells. We also show a potential application of these bacterial liposomes in delivery of aqueous molecules to cancer cells. We show not only intracellular uptake, but also biodegradation of the liposomes inside cancer cells. Our economical liposomes promise to serve as excellent model systems for studies on encapsulation of molecules inside soft materials with desired efficiencies. Additionally, they certainly show a strong potential to be tools for research in diverse areas ranging from drug delivery applications to sub-micron reaction engineering for carrying out and understanding the mechanisms of chemical reactions in small enclosed volumes.

Glycerol Stock Preparation for S. elongatus v1

2021 ◽  
Author(s):  
Akashdutta not provided
Keyword(s):  
Low Temperatures ◽  
Bacterial Cells ◽  
Liquid Cultures ◽  
Bacterial Cultures ◽  
Long Term Storage ◽  
The Media ◽  
Term Storage

Bacterial cultures in the form of agar plates or liquid cultures are not suitable for long term storage at low temperatures such as 4 degrees. Long-term storage of bacteria is best at temperatures around -80 degrees. However, agar plates and liquid cultures cannot be stored at such temperatures, as the water crystallizes in and around the bacterial cells, rupturing and killing them. Glycerol or DMSO (anti-freezing agents) is added to the media to store samples at such temperatures.

DMSO stock preparation v1

2021 ◽  
Author(s):  
Akashdutta not provided
Keyword(s):  
Low Temperatures ◽  
Bacterial Cells ◽  
Liquid Cultures ◽  
Bacterial Cultures ◽  
Long Term Storage ◽  
The Media ◽  
Term Storage

Bacterial cultures in the form of agar plates or liquid cultures are not suitable for long term storage at low temperatures such as 4oC. Long-term storage of bacteria is best at temperatures around -80oC. However, agar plates and liquid cultures cannot be stored at such temperatures, as the water crystallizes in and around the bacterial cells, rupturing and killing them. Glycerol or DMSO (anti-freezing agents) is added to the media to store samples at such temperatures.

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.

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).

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