scholarly journals Pseudomonas fluorescens proliferates in a mouse organ homogenate at low temperature

2008 ◽  
Author(s):  
Yota Tatara ◽  
Takahiro Terakawa ◽  
Youhei Yamagata ◽  
Takafumi Uchida
Keyword(s):  
Low Temperature ◽  
Pseudomonas Fluorescens ◽  
Mouse Organ

scholarly journals Denitrification performance of Pseudomonas fluorescens Z03 immobilized by graphene oxide-modified polyvinyl-alcohol and sodium alginate gel beads at low temperature

2020 ◽  
Vol 7 (3) ◽  
pp. 191542 ◽  
Author(s):  
Meizhen Tang ◽  
Jie Jiang ◽  
Qilin Lv ◽  
Bin Yang ◽  
Mingna Zheng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Temperature ◽  
Polyvinyl Alcohol ◽  
Pseudomonas Fluorescens ◽  
Sodium Alginate ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Aerobic Denitrification ◽  
Gel Beads

Improving the effect of microbial denitrification under low-temperature conditions has been a popular focus of research in recent years. In this study, graphene oxide (GO)-modified polyvinyl-alcohol (PVA) and sodium alginate (SA) (GO/PVA–SA) gel beads were used as a heterotrophic nitrification–aerobic denitrification (HN–AD) bacteria ( Pseudomonas fluorescens Z03) carrier to enhance nitrogen removal efficiency levels at low temperatures (6–8°C). The removal efficiency of N H 4     + -N and N O 3       − -N and the variations in concentrations of extracellular polymeric substances (EPS) under different GO doses (0.03–0.15 g l −1 ) were studied. The results indicated that the addition of GO can improve the efficiency of nitrogen removal, and the highest removal efficiency level and highest carbohydrate, protein, and total EPS content levels (50.28 mg, 132.78 mg and 183.06 mg (g GO/PVA–SA gel) −1 , respectively) were obtained with 0.15 g l −1 GO. The simplified Monod model accurately predicted the nitrogen removal efficiency level. These findings suggested that the application of GO serves as an effective means to enhance nitrogen removal by stimulating the activity of HN–AD bacteria.

Use of Microwave Ovens to Pasteurize Milk

1988 ◽  
Vol 51 (9) ◽  
pp. 715-719 ◽  
Author(s):  
KATHLEEN M. KNUTSON ◽  
ELMER H. MARTH ◽  
MARY K. WAGNER
Keyword(s):  
Escherichia Coli ◽  
High Temperature ◽  
Low Temperature ◽  
Salmonella Typhimurium ◽  
Pseudomonas Fluorescens ◽  
Water Bath ◽  
Streptococcus Faecalis ◽  
High Temperature Short Time ◽  
Long Time ◽  
Short Time

High-temperature short-time (HTST) and low-temperature long-time (LTLT) pasteurization were simulated using uninoculated and inoculated milks that were heated in microwave ovens. Heating milk (76 ml) for 59 s at 700 W achieved a temperature of 71.7°C, but heating for 60–65 s and holding for 15 s failed to inactivate all added cells of Salmonella typhimurium, Escherichia coli or Pseudomonas fluorescens. Milk, 453.6 g (ca. one-half quart) or 604.8 g (ca. two-thirds quart), was heated to >62.8°C, but <71.7°C, in 4.5 to 5 min, depending on power (550 or 700 W) that was used, and refrigerated overnight. Such treatments failed to reduce the population of Streptococcus faecalis in the milks by the degree that occurred when inoculated milk was heated in a water bath at 62.8°C for 30 min.

scholarly journals Influence of incubation conditions on biofilm formation by Pseudomonas fluorescens isolated from dairy products and dairy manufacturing plants

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Chiara Rossi ◽  
Clemencia Chaves-López ◽  
Annalisa Serio ◽  
Elisa Goffredo ◽  
Beniamino Terzo Cenci Goga ◽  
...  
Keyword(s):  
Low Temperature ◽  
Pseudomonas Fluorescens ◽  
Incubation Time ◽  
Food Processing ◽  
Biofilm Formation ◽  
Dairy Products ◽  
Great Variability ◽  
Manufacturing Plants ◽  
Cleaning And Disinfection ◽  
Strain Dependent

In this study, biofilm formation of 64 <em>Pseudomonas fluorescens</em> strains isolated from milk, dairy products and dairy plants was compared. The strains were grown on Tryptic Soy Broth supplemented with 0.2% of glucose, on polystyrene microplates at 10 and 30°C for 48 h. In general, 57/64 <em>P. fluorescens</em> strains formed biofilm, although with great variability at both tested temperatures. Moreover, our results evidenced that the biofilm-forming ability of the strains was temperature- and strain-dependent. Interestingly, the ability of several isolates to form biofilms was associated with the low temperature after 48 h. Our findings evidenced that temperature was more important than incubation time for biofilm formation. Considering the origin of the strains, it is relevant to underline the importance of performing accurate cleaning and disinfection procedures on food processing surfaces.

In silico  structural and functional analysis of cold shock protein in Pseudomonas fluorescens  PF08 from marine fish

2021 ◽  
Author(s):  
Xu Jinxiu ◽  
Qiuying Li ◽  
Zhang Jingyang ◽  
Li Xuepeng ◽  
Sun Tong ◽  
...  
Keyword(s):  
Low Temperature ◽  
Pseudomonas Fluorescens ◽  
Marine Fish ◽  
Stress Responses ◽  
Binding Sites ◽  
Cold Shock ◽  
Rna Binding ◽  
Rna Degradation ◽  
Temperature Adaptation ◽  
Cold Shock Protein

Pseudomonas fluorescens is a specific spoilage microorganism of refrigerated marine fish, which possesses strong adaptability to low temperature. Cold shock proteins (CSPs) play an important role in bacterial cold adaptation. In this study, the CSP genes were obtained from the genome of P. fluorescens PF08 by search the conserved domain of CSPs through HMMER software, and their physicochemical property, structure and function were analyzed by bioinformatics. A total of five typical CSPs are identified in P. fluorescens PF08 genome (PfCSPs). The results showed that the five PfCSPs are all small hydrophilic acidic proteins with molecular weight around 7.4 kDa. They are located in the cytoplasm and are non-secretory and non-transmembrane proteins. Multiple sequence alignment analysis indicated the CSPs were highly conserved between different species, especially in DNA-binding sites and RNA-binding motifs that can bind to single-stranded DNA and RNA. The five PfCSPs were clustered together with CspD from Escherichia coli and Salmonella typhimurium , which suggested that a close homology and high functional similarity among the five PfCSPs and CspD. The secondary and tertiary structures of the PfCSPs are accordance with the characteristics of the CSPs family and ligand binding sites with higher likelihood were found in PfCSPs. The five PfCSPs were predicted to interact with some of the same proteins that involved in virulence, stress responses (including low temperature), cell growth, ribosome assembly and RNA degradation. The results provides references for further elucidation of the function of CSPs in the process of low temperature adaptation of P. fluorescens .

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Low temperature x-ray microanalysis of frozen-hydrated tobacco leaves

1984 ◽  
Vol 42 ◽  
pp. 284-285
Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes
Keyword(s):  
Low Temperature ◽  
Lemna Minor ◽  
Root Tips ◽  
Tobacco Leaves ◽  
X Ray ◽  
Whole Cells ◽  
Carbon Coated ◽  
The Right ◽  
Beam Currents ◽  
The University

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

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