scholarly journals The preservation of bacteriophage H1 of Corynebacterium ulcerans U 103 by freeze-drying

1969 ◽  
Vol 67 (4) ◽  
pp. 573-583 ◽  
Author(s):  
J. D. Davies ◽  
M. J. Kelly
Keyword(s):  
Freeze Drying ◽  
Room Temperature ◽  
Freezing Damage ◽  
Drying Process ◽  
Initial Sample ◽  
Corynebacterium Ulcerans ◽  
Sucrose Solutions ◽  
Rate Of Cooling ◽  
Logarithmic Relationship ◽  
Marked Drop

SUMMARYThis paper describes an investigation into the successful preservation at room temperature of the bacteriophage H1 of Corynebacterium ulcerans U 103 which was extremely labile when in suspension at 4° C.Cooling at a rate of 1° C./min. showed that the survival decreased logarithmically at temperatures between – 14 and – 45° C. Survival of broth suspensions of the corynebacteriophage were found to increase proportionally with an increase in the rate of cooling though there was a marked drop in survival at rates of approximately 900° C./min. The addition of peptone solutions was found to increase the survival over the range studied, whereas the addition of sucrose solutions had only a slight effect.By avoiding freezing damage by cooling at rates of 450° C./min. in (a) 20% peptone solution, (b) 20% peptone and 10% sucrose, and (c) 20% peptone, 10% sucrose and 2% sodium glutamate, a study was made of the drying stage of the freeze-drying process. On drying at controlled temperatures it was found that there was no damage on rewarming to temperatures below – 21° C. after cooling to – 196° C., but that the survival immediately after drying in the absence of glutamate, showed a logarithmic relationship with the temperature of drying, lower temperatures giving better survival.On storage for a period of 3 months at room temperature in vacuo and darkness, there was no appreciable loss in survival in the mixtures though suspensions in peptone alone showed a slight decrease. At higher temperatures this decrease in survival could be differentiated into two types of damage, each of which could be influenced by the presence of sucrose or glutamate.We are grateful to Professor H. R. Carne for providing the initial sample of bacteriophage H 1 of Corynebacterium ulcerans U 103, and to Professor R. I. N. Greaves for his interest and encouragement during the course of this investigation.

scholarly journals Pengaruh Proses Freeze-Drying dan Penyimpanan pada Suhu Kamar terhadap Viabilitas dan Patogenisitas Plasma Nutfah Mikroba Pasteurella Multocida

2016 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Siti Chotiah
Keyword(s):  
Freeze Drying ◽  
Room Temperature ◽  
Pasteurella Multocida ◽  
Culture Collection ◽  
Pathogenicity Test ◽  
Drying Process ◽  
Colony Forming Unit ◽  
Freeze Dried ◽  
Conservation Method ◽  
Preservation Medium

<p>The effect of freeze-drying process and preserving in a vacuum at room temperature against viability and pathogenicity of veterinary microbe germ plasma of Pasteuerella multocida BCC 2331 was investigated at Balitvet. The aim of this study was to find out the most effective and efficient conservation method. As much as 5,2 x 1011 colony forming unit (CFU)/ml of bacteria suspension in 7.5% glucose serum as the preservation medium being pathogenic in mice with LD50 of 9,8 CFU/ml was freeze dried then stored at room temperature (&amp;plusmn;27oC) until the study was completed. Viability and pathogenicity test were done immediately after the process, 1 and 2 months after storage. The results showed that there were viability decreases amounted 1,3 x 101 CFU/ml, 102 CFU/ml and 8,2 x l02 CFU/m1 due to the effects of the process, one month and two-month storage respectively. The decreases of pathogenicity on mice were shown by the increases of LD50 amounting log 1, log 2, and log 3 a day after the process, one month and two-month storage respectively.</p><p> </p><p><strong>Abstrak</strong></p><p>Pengaruh proses kering beku dan penyimpanan hasil proses pada suhu kamar 27oC terhadap viabilitas dan patogenisitas plasma nutfah mikroba veteriner telah dipelajari di Balitvet untuk menentukan cara pelestarian yang efektif dan efisien. Dalam kegiatan ini dipakai bakteri Pasteurella multocida koleksi Balitvet Culture Collection nomor koleksi B2331. Suspensi bakteri sebanyak 5,2 x l011 coloni forming unit (CFU)/ml dalam medium preservan 7,5% glukosa, serum dan bersifat patogen pada mencit dengan LD50 9,8 CFU/ml diproses kering beku, kemudian disimpan pada suhu kamar (+27oC) sampai penelitian selesai. Uji viabilitas dan patogenisitas dilakukan langsung setelah proses dan pada 1 serta 2 bulan setelah penyimpanan. Hasil penelitian menunjukkan terjadi penurunan viabilitas sebanyak 1,3 x 101 CFU, dan 8,2 x 102 CFU/ml masingmasing karena pengaruh proses, pengaruh penyimpanan selama 1 dan 2 bulan. Patogenisitas pada mencit menurun yang ditandai oleh adanya peningkatan LD50 sebanyak log 1, log 2, dan log 3 masing-masing 1 hari setelah proses, 1 dan 2 bulan setelah penyimpanan.</p>

scholarly journals Impact of shelf temperature on freeze-drying process and porosity development

2018 ◽  
Author(s):  
M. M. Camacho ◽  
L. A. Egas-Astudillo ◽  
A. Silva ◽  
M. Uscanga ◽  
N. Martínez-Navarrete
Keyword(s):  
Freeze Drying ◽  
Room Temperature ◽  
Gum Arabic ◽  
Drying Kinetics ◽  
Drying Process ◽  
Drying Time ◽  
Lower Porosity ◽  
The Impact ◽  
Shelf Temperature ◽  
Porosity Development

The freeze-drying kinetics and the superficial porosity development of grapefruit puree. The impact of biopolymers addition (gum Arabic and bamboo fiber) and to apply (40 ºC) or not shelf temperature (room temperature) was considered. To increase the shelves temperature during freeze-drying allowed to an important drying time reduction and doesn’t supposed a lower porosity related to the collapse development of the structure. Biopolymers do not affect the drying kinetics. From this results, biopolymers addition and to heat at least up to 40 ºC during grapefruit freeze-drying should be recommended. Keywords: freeze-drying; shelf temperature; drying kinetics; image analysis; pore size distribution.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

High-Resolution Scanning Electron Microscopy of Biological Specimens

1988 ◽  
Vol 46 ◽  
pp. 186-187
Author(s):  
M. Müller ◽  
R. Hermann
Keyword(s):  
High Resolution ◽  
Freeze Drying ◽  
Room Temperature ◽  
Structural Information ◽  
Freeze Substitution ◽  
Critical Point Drying ◽  
Sem Study ◽  
Major Factors ◽  
Structural Preservation ◽  
Preparation Techniques

Three major factors must be concomitantly assessed in order to extract relevant structural information from the surface of biological material at high resolution (2-3nm).Procedures based on chemical fixation and dehydration in graded solvent series seem inappropriate when aiming for TEM-like resolution. Cells inevitably shrink up to 30-70% of their initial volume during gehydration; important surface components e.g. glycoproteins may be lost. These problems may be circumvented by preparation techniques based on cryofixation. Freezedrying and freeze-substitution followed by critical point drying yields improved structural preservation in TEM. An appropriate preservation of dimensional integrity may be achieved by freeze-drying at - 85° C. The sample shrinks and may partially collapse as it is warmed to room temperature for subsequent SEM study. Observations at low temperatures are therefore a necessary prerequisite for high fidelity SEM. Compromises however have been unavoidable up until now. Aldehyde prefixation is frequently needed prior to freeze drying, rendering the sample resistant to treatment with distilled water.

Investigations on the Nature of Hemophilia A

1963 ◽  
Vol 09 (01) ◽  
pp. 030-052 ◽  
Author(s):  
Eberhard Mammen
Keyword(s):  
Factor Viii ◽  
Human Plasma ◽  
Barium Sulfate ◽  
Freeze Drying ◽  
Room Temperature ◽  
Hemophilia A ◽  
Normal Human Plasma ◽  
Normal Human ◽  
And Storage ◽  
Prothrombin Activation

SummaryIn this paper an inhibitor is described that is found in hemophilic plasma and serum different from any till now described inhibitor. The inhibitor only inhibits prothrombin activation in the “intrinsic clotting systems”. This inhibitor is probably not present in normal human plasma or serum. It is destroyed by ether and freeze drying, is labile to acid and storage at room temperature. It is stable upon dialysis and has not been adsorbed on barium sulfate, aluminum hydroxide or kaolin. It precipitates at 50% v/v saturation with alcohol. The nature of this inhibitor seems to be a protein or lipoprotein.Factor VIII was isolated from hemophilic plasma. The amount isolated was the same as from normal plasma and the activity properties were not different. Hemophiliacs have normal amounts of factor VIII.

scholarly journals Strengthening of Porcine Plasma Protein Superabsorbent Materials through a Solubilization-Freeze-Drying Process

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 772
Author(s):  
Estefanía Álvarez-Castillo ◽  
Carlos Bengoechea ◽  
Antonio Guerrero
Keyword(s):  
Water Uptake ◽  
Plasma Protein ◽  
Freeze Drying ◽  
Meat Industry ◽  
Drying Process ◽  
Uptake Capacity ◽  
Water Uptake Capacity ◽  
Protein Flour ◽  
Hydrophilic Materials ◽  
By Products

The replacement of common acrylic derivatives by biodegradable materials in the formulation of superabsorbent materials would lessen the associated environmental impact. Moreover, the use of by-products or biowastes from the food industry that are usually discarded would promote a desired circular economy. The present study deals with the development of superabsorbent materials based on a by-product from the meat industry, namely plasma protein, focusing on the effects of a freeze-drying stage before blending with glycerol and eventual injection molding. More specifically, this freeze-drying stage is carried out either directly on the protein flour or after its solubilization in deionized water (10% w/w). Superabsorbent materials obtained after this solubilization-freeze-drying process display higher Young’s modulus and tensile strength values, without affecting their water uptake capacity. As greater water uptake is commonly related to poorer mechanical properties, the proposed solubilization-freeze-drying process is a useful strategy for producing strengthened hydrophilic materials.

Effects of Drying Temperature on Surface Morphology and Electric Behavior of IGZO Thin Film Prepared by Solution Process

2015 ◽  
Vol 1731 ◽  
Author(s):  
Nobuko Fukuda ◽  
Shintaro Ogura ◽  
Koji Abe ◽  
Hirobumi Ushijima
Keyword(s):  
Thin Film ◽  
Organic Solvents ◽  
Room Temperature ◽  
Thin Film Transistor ◽  
Solution Process ◽  
Precursor Solution ◽  
Drying Process ◽  
Minor Variation ◽  
Drying Temperature ◽  
Metal Nitrates

ABSTRACTWe have achieved a drastic improvement of the performance as thin film transistor (TFT) for solution-processed IGZO thin film by controlling drying temperature of solvents containing the precursor solution. The IGZO-precursor solution was prepared by mixing of metal nitrates and two kinds of organic solvents, 2-methoxyethanol (2ME) and 2,2,2-trifluoroethanol (TFE). 2ME was used for dissolving metal nitrates. TFE was added as a solvent for reducing surface tension as small as possible, leading to improvement of the wettability of the precursor solution on the surface of the substrate. In order to discuss the relationship between morphology and drying process, the spin-coated IGZO-precursor films were dried at room temperature and 140 °C on a hotplate, respectively. Annealing of the both films was carried out at 300 °C in an electric oven for 60 min after each drying process. Drying at room temperature provides a discontinuous film, resulting in a large variation of the TFT performance. On the other hand, drying at 140 °C provides a continuous film, resulting in the higher TFT performance and a minor variation. The difference in surface morphologies would be derived from the evaporation rate of the organic solvents. The rapid evaporation at 140 °C brings about rapid pinning of the spin-coated precursor layer on the substrate. Preparation process via the drying at 140 °C gave ∼ 1 cm2 V-1 s-1 of the saturated mobility, quite small hysteresis, and 107∼ 108 of the on-off ratio.

Sign in / Sign up

Export Citation Format

Share Document