scholarly journals Isolation and Characterization of Vibrio kanaloae as a Major Pathogen Associated with Mass Mortalities of Ark Clam, Scapharca broughtonii, in Cold Season

2021 ◽  
Vol 9 (10) ◽  
pp. 2161
Author(s):  
Bowen Huang ◽  
Xiang Zhang ◽  
Chongming Wang ◽  
Changming Bai ◽  
Chen Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Optimal Growth ◽  
Cold Season ◽  
Opportunistic Pathogens ◽  
Growth Ratio ◽  
Isolation And Characterization ◽  
Scapharca Broughtonii ◽  
Different Temperatures

High temperature is a risk factor for vibriosis outbreaks. Most vibrios are opportunistic pathogens that cause the mortality of aquatic animals at the vibrio optimal growth temperature (~25 °C), whereas a dominant Vibrio kanaloae strain SbA1-1 is isolated from natural diseased ark clams (Scapharca broughtonii) during cold seasons in this study. Consistent symptoms and histopathological features reappeared under an immersion infection with SbA1-1 performed at 15 °C. The pathogenicity difference of SbA1-1 was assessed under different temperatures (15 °C and 25 °C). The cumulative mortality rates of ark clams were significantly higher at the low temperature (15 °C) than at the high temperature (25 °C); up to 98% on 16th day post SbA1-1 infection. While the growth ratio of SbA1-1 was retarded at the low temperature, the hemolytic activity and siderophores productivity of SbA1-1 were increased. This study constitutes the first isolation of V. kanaloae from the natural diseased ark clams (S. broughtonii) in cold seasons and the exposition of the dissimilar pathogenicity of SbA1-1 at a different temperature. All the above indicates that V. kanaloae constitutes a threat to ark clam culture, especially in cold seasons.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

A Method for Predicting the Behavior of Plastics at Different Temperatures

2014 ◽  
Vol 1039 ◽  
pp. 107-111
Author(s):  
Yang Chen ◽  
Gui Qin Li ◽  
Bin Ruan ◽  
Xiao Yuan ◽  
Hong Bo Li
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Constitutive Model ◽  
Research And Development ◽  
Mechanical Behavior ◽  
Plastic Material ◽  
Different Temperatures ◽  
Plastic Parts

The mechanical behavior of plastic material is dramatically sensitive to temperature. An method is proposed to predict the mechanical behavior of plastics for cars, ranging from low-temperature low temperature ≤-40°C to high temperature ≥80°C. It dominates the behavior of plastic material based on improved constitutive model in which the parameters adjusted by a series of tests under different temperatures. The method is validated with test and establishes the basis for research and development of plastic parts for automobile as well.

Synthesis and Characterization of Aerogel-derived Cation-substituted Hexaaluminates

1996 ◽  
Vol 457 ◽  
Author(s):  
Lin-chiuan Yan ◽  
Levi T. Thompson
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Catalytic Combustion ◽  
High Surface ◽  
High Surface Area ◽  
Synthesis And Characterization ◽  
New Methods ◽  
Surface Areas ◽  
Different Characteristics

ABSTRACTNew methods have been developed for the synthesis of high surface area cation-substituted hexaaluminates. These materials were prepared by calcining high temperature (ethanol extraction) or low temperature (CO2 extraction) aerogels at temperatures up to 1600°C. Cation-substituted hexaaluminates have emerged as promising catalysts for use in high temperature catalytic combustion. In comparing unsubstituted and cation-substituted hexaaluminates, we found that the phase transformations were much cleaner for the cation-substituted materials. BaCO3 and BaAl2O4 were intermediates during transformation of the unsubstituted materials, while the cation-substituted materials transformed directly from an amorphous phase to crystalline hexaaluminate. Moreover, the presence of substitution cations caused the transformation to occur at lower temperatures. Mn seems to be a better substitution cation than Co since the Mn-substituted materials exhibited higher surface areas and better heat resistances than the Co-substituted materials. The low temperature aerogel-derived materials possessed quite different characteristics from the high temperature aerogel-derived materials. For example, phase transformation pathways were different.

Isolation and characterization of Thermococcus sibiricus sp. nov. from a Western Siberia high-temperature oil reservoir

Extremophiles ◽  
2001 ◽  
Vol 5 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Margarita Miroshnichenko ◽  
Hans Hippe ◽  
Erko Stackebrandt ◽  
Nadezhda Kostrikina ◽  
Nikolai Chernyh ◽  
...  
Keyword(s):  
High Temperature ◽  
Western Siberia ◽  
Oil Reservoir ◽  
Isolation And Characterization

Isolation and characterization of Vibrio harveyi as a major pathogen associated with mass mortalities of ark clam, Scapharca broughtonii, in summer

Aquaculture ◽  
2019 ◽  
Vol 511 ◽  
pp. 734248 ◽  
Author(s):  
Zhixin Wei ◽  
Lusheng Xin ◽  
Weiwei Zhang ◽  
Changming Bai ◽  
Chongming Wang ◽  
...  
Keyword(s):  
Vibrio Harveyi ◽  
Isolation And Characterization ◽  
Scapharca Broughtonii ◽  
Mass Mortalities

scholarly journals Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

2016 ◽  
Vol 37 (3) ◽  
pp. 403-419 ◽  
Author(s):  
Paris Lavín ◽  
Cristian Atala ◽  
Jorge Gallardo-Cerda ◽  
Marcelo Gonzalez-Aravena ◽  
Rodrigo De La Iglesia ◽  
...  
Keyword(s):  
Alginate Lyase ◽  
Enzymatic Activities ◽  
Maximum Temperature ◽  
Rrna Gene ◽  
King George Island ◽  
Optimal Temperature ◽  
16S Rrna Gene Analysis ◽  
Isolation And Characterization ◽  
Different Temperatures

AbstractSeveral bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta), in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17ºC) and maximum temperature (20°C) of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C), agarose (50°C) and alginate (30°C) during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.

Isolation and Characterization of Rhodopseudomonas sp. S9-1 Capable of Degrading Pyrazosulfuron-Ethyl

2011 ◽  
Vol 356-360 ◽  
pp. 1152-1163 ◽  
Author(s):  
Le Bin Yin ◽  
Yong Liu ◽  
De Yong Zhang ◽  
Song Bai Zhang
Keyword(s):  
Contaminated Soil ◽  
Acetolactate Synthase ◽  
Optimal Growth ◽  
Degradation Process ◽  
Amino Acid Sequences ◽  
Rrna Gene ◽  
Photosynthetic Membrane ◽  
Physiological And Biochemical Characteristics ◽  
Isolation And Characterization

A bacterial strain S9-1capable of degrading sulfonylurea herbicide pyrazosulfuron-ethyl (PSE) was isolated from contaminated soil through the enrichment incubation method. Based on morphology, colony and cultural properties, physiological and biochemical characteristics, living-cell absorption spectra, internal photosynthetic membrane, and phylogenetics of its 16S rRNA gene sequence, S9-1was preliminarily identified as belonging to the genus Rhodopseudomonas, a group of photosynthetic bacteria (PSB). The effects of PSE concentration, pH, and temperature on biodegradation were examined. The degradation rate was found to decrease with increasing PSE concentration. Optimal growth pH and temperature were found to be 7.0 and 30°C, respectively. The strain was able to degrade 47.51% of PSE at a concentration of 100 mg ml-1after 7 days of incubation at 30°C and could tolerate 800 mg ml-1PSE. S9-1was also able to completely co-metabolically transform 100 mg ml-1PSE at 30°C, pH 7.0, and 7500 lux in 15 days. As the concentration of PSE increased, the degradation process took longer to complete. The fragment encoding acetolactate synthase (ALS) gene from S9-1was cloned and sequenced. Comparison of deduced amino acid sequences was implemented, and the conserved sites were analyzed. To our knowledge, this is the first report of PSB in PSE biodegradation. These results highlight the potential of this bacterium as a detoxifying agent for use with PSE-contaminated soil and wastewater.

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