Environmental factors affecting germination of Cronartium comandrae aeciospores

1974 ◽  
Vol 52 (3) ◽  
pp. 659-667 ◽  
Author(s):  
J. M. Powell
Keyword(s):  
Environmental Factors ◽  
Germ Tube ◽  
Free Water ◽  
Direct Sunlight ◽  
Factors Affecting ◽  
Temperature Range ◽  
Ph Range ◽  
Germ Tubes ◽  
Germ Tube Elongation

Cronartium comandrae Pk. aeciospores germinated over the temperature range 1 to 30 °C, but germination outside the range 5 to 22 °C was poor. Optimum for germination was about 15 °C, although initial germination was better at 20 °C. Some aeciospores germinated after 1 h of incubation and most within 4 to 5 h. The rate of germ tube elongation was reduced after 8 h, and generally had ceased after 24 h. Each spore produced an average of two germ tubes, but only one developed. Appressoria usually formed only at 15 and 20 °C. Free water was apparently necessary for germination. Hydration of spores initially improved germination but extended periods of hydration decreased it. Viable spores swelled more than non-viable spores. Aeciospores germinated well in the dark and in light but not in direct sunlight. Fresh aeciospores germinated on media with a pH range of 4.5 to 8.0, but did best between pH 6.0 and 6.5. Germination results are compared with those reported for other Cronartium rusts.

Carbon dioxide induces endotrophic germ tube formation in Candida albicans

1990 ◽  
Vol 36 (4) ◽  
pp. 249-253 ◽  
Author(s):  
Ruth C. Mock ◽  
Jordan H. Pollack ◽  
Tadayo Hashimoto
Keyword(s):  
Carbon Dioxide ◽  
Candida Albicans ◽  
Sodium Bicarbonate ◽  
Key Words ◽  
Germ Tube ◽  
Tube Formation ◽  
Chemical Inducers ◽  
Tube Emergence ◽  
Ph Range ◽  
Germ Tubes

Candida albicans formed germ tubes when exposed to air containing 5 to 15% carbon dioxide (CO2). The CO2-mediated germ tube formation occurred optimally at 37 °C in a pH range of 5.5 to 6.5. No germ tubes were produced at 25 °C, even when the optimal concentration of CO2 (10%) was present in the environment. The requirement of CO2 for germ tube formation could be partially substituted by sodium bicarbonate but not by N2. Carbon dioxide was required to be present throughout the entire course of germ tube emergence suggesting that its role is not limited to an initial triggering of morphogenic change. We suggest that carbon dioxide may be a common effector responsible for the germ tube promoting activity of certain chemical inducers for C. albicans. Key words: Candida albican germ tubes, CO2-induced germ tube formation, endotrophic germ tube formation.

Factors affecting spread of Cronartiumcomptoniae on the sweetfern host

1981 ◽  
Vol 11 (2) ◽  
pp. 401-409 ◽  
Author(s):  
Dale L. K. Smeltzer ◽  
D. W. French
Keyword(s):  
Spore Germination ◽  
Free Water ◽  
Dispersal Distance ◽  
Growth Chamber ◽  
Spore Viability ◽  
Factors Affecting ◽  
Temperature Range ◽  
Field Plots

Infection of sweetfern plants (Comptoniaperegrina (L.) Coult.) by Cronartiumcomptoniae Arth. was observed at a maximum of 30 m from the aeciospore source on two field plots in northeastern Minnesota, U.S.A. Amount of infection per spores trapped decreased significantly as dispersal distance increased from the source of inoculum. Infection of sweetfern was limited most by the decrease in spore viability, but lack of rain may have limited infection at least twice during the summer. Inoculations of sweetfern with aeciospores and uredospores in a growth chamber resulted in infection at 0–28 °C, a wider temperature range than for spore germination on agar. Infection occurred after 1 h in a humid chamber and was inhibited by light, especially high intensities. Free water and spores on the undersurface of the sweetfern leaf were required for infection.

The requirements for bicarbonate and metabolism of the inducer during germ tube formation by Candida albicans

1988 ◽  
Vol 34 (11) ◽  
pp. 1183-1188 ◽  
Author(s):  
Jordan H. Pollack ◽  
Tadayo Hashimoto
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Tube Formation ◽  
Factors Affecting ◽  
Ph Values ◽  
Germ Tubes

Factors affecting germ tube formation in Candida albicans at suboptimal temperatures were investigated. Candida albicans formed germ tubes between 22 and 30 °C in solution when incubated without shaking, in the presence of bicarbonate (2 mg mL−1). Other conditions depended on the inducer used. Proline could induce germ tube formation optimally only when its concentration was between 200 and 400 mM. A concentration of 0.05 mM N-acetylglucosamine was sufficient to induce germ tube formation. N-Acetylglucosamine could induce germ tube formation at 30 but not at 25 °C. N-Acetylglucosamine induced germ tube formation was most reproducible when the cells were first starved by incubation in water for 16–24 h at 20 °C. Germ tubes induced by proline could be formed at pH values between 3.8 and 9.0 at 30 °C, but only between 7.0 and 7.5 at 25 °C. The addition of 0.05 to 5 mM glucose to a 5 mM proline induction solution allowed germ tube formation at 30 but not at 25 °C. Glucose (400 mM) did not suppress germ tube formation at 30 °C but only 5 mM was sufficient to cause a 65% suppression at 25 °C. The results show the importance of CO2 and (or) bicarbonate to the induction of germ tube formation and are consistent with the metabolism of the inducer.

Environmental factors affecting reproducibility of bioremediation field assays in Antarctica

2020 ◽  
Vol 169 ◽  
pp. 102915 ◽  
Author(s):  
L.M. Martínez Álvarez ◽  
L.A.M. Ruberto ◽  
J.M. Gurevich ◽  
W.P. Mac Cormack
Keyword(s):  
Environmental Factors ◽  
Factors Affecting

scholarly journals Marisediminicola antarctica gen. nov., sp. nov., an actinobacterium isolated from the Antarctic

2010 ◽  
Vol 60 (11) ◽  
pp. 2535-2539 ◽  
Author(s):  
Hui-Rong Li ◽  
Yong Yu ◽  
Wei Luo ◽  
Yin-Xin Zeng
Keyword(s):  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Intertidal Sediment ◽  
Rrna Gene ◽  
Optimum Growth ◽  
Temperature Range ◽  
Zhongshan Station ◽  
Diamino Acid ◽  
Ph Range ◽  
The Antarctic

Strain ZS314T was isolated from a sandy intertidal sediment sample collected from the coastal area off the Chinese Antarctic Zhongshan Station, east Antarctica (6 ° 22′ 13″ S 7 ° 21′ 41″ E). The cells were Gram-positive, motile, short rods. The temperature range for growth was 0–26 °C and the pH for growth ranged from 5 to 10, with optimum growth occurring within the temperature range 18–23 °C and pH range 6.0–8.0. Growth occurred in the presence of 0–6 % (w/v) NaCl, with optimum growth occurring in the presence of 2–4 % (w/v) NaCl. Strain ZS314T had MK-10 as the major menaquinone and anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0 as major fatty acids. The cell-wall peptidoglycan type was B2β with ornithine as the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C content was approximately 67 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain ZS314T represents a new lineage in the family Microbacteriaceae. On the basis of the phylogenetic analyses and phenotypic characteristics, a new genus, namely Marisediminicola gen. nov., is proposed, harbouring the novel species Marisediminicola antarctica sp. nov. with the type strain ZS314T (=DSM 22350T =CCTCC AB 209077T).

Dynamic Study on Vacuum Pyrolysis Reaction of Chinese Fir Sawdust Biomass

2012 ◽  
Vol 512-515 ◽  
pp. 375-378
Author(s):  
Su Wen Yang ◽  
Jian Min Yi ◽  
Ke Qiang Qiu ◽  
Xin Deng ◽  
Jian Shan Chen
Keyword(s):  
Heating Rate ◽  
Free Water ◽  
Chinese Fir ◽  
Peak Temperature ◽  
Gravimetric Analysis ◽  
Water Desorption ◽  
Exponential Factor ◽  
Pyrolysis Reaction ◽  
Temperature Range ◽  
Vacuum Pyrolysis

This thesis does thermal gravimetric analysis（TGA）studies on Chinese fir sawdust biomass by integrated thermal analyzer under vacuum conditions. Through the analysis on lostmass curve at different heating rate of 10, 15, 20 and 30°C/min, we found the process of Chinese fir sawdust vacuum pyrolysis can be mainly divided into three stages: evaporation of free water and combined water desorption, rapid lostmass of pyrolysis and slow decomposition of residues. The lostmass major temperature range is between 250 ~ 450°C, the peak temperature is between 365 ~ 400°C. When the pyrolysis temperature is 500°C, vacuum pyrolysis reaction of Chinese fir sawdust has basically completed. As the heating rate rises, the lostmass curve is moving to the right, the peak temperature is shifting to higher temperature, and the temperature range of thermal decomposition reaction widens significantly. According to experimental datas, we tried to obtain the vacuum pyrolysis dynamic parameters of Chinese fir sawdust, and the results are that the apparent activation energy of vacuum pyrolysis reaction of Chinese fir sawdust biomass is 128.34kJ/mol, with the pre-exponential factor being 6.42×109 and reaction order being 1.08, similar to first order reaction.

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