Effects of temperature on the growth of psychrophilic bacteria from glaciers

1976 ◽  
Vol 22 (6) ◽  
pp. 839-846 ◽  
Author(s):  
A. M. Gounot
Keyword(s):  
Cell Wall ◽  
Thermal Stress ◽  
Viable Count ◽  
Optimum Temperature ◽  
Cell Wall Synthesis ◽  
Psychrophilic Bacteria ◽  
Different Temperatures ◽  
Abnormal Cells ◽  
Effects Of Temperature ◽  
Arthrobacter Species

Growth of five strains of psychrophilic bacteria (four Arthrobacter and one Pseudomonas) isolated from glacial deposits was studied at different temperatures. Three strains were facultative psychrophiles, having an optimum temperature for growth at about 25–28 °C and a maximum at about 32–34 °C. The two Arthrobacter glacialis strains were found to be obligate psychrophiles with an optimum at 13–15 °C and a maximum at 18 °C. Arrhenius plots showed that A. glacialis could compete with the facultative psychrophilic bacteria only at 0 °C, that is, the temperature of its natural environment. The psychrophilic Arthrobacter species studied here are more resistant to thermal stress than are marine psychrophilic bacteria.For Arthrobacter, in contrast to Pseudomonas, temperatures above the optimum induced formation of filaments and abnormal cells. The culture turbidity increased 10 to 30 times, whereas viable count tended to decrease. The thermal block seems to prevent cell wall synthesis and septation, but at a different step for each species.

scholarly journals The Effect of Hydroxylysine on Cell Wall Synthesis and Cell Stability in Streptococcus faecalis

1962 ◽  
Vol 237 (4) ◽  
pp. 1198-1202
Author(s):  
W. Grady Smith ◽  
Mary Newman ◽  
Franklin R. Leach ◽  
L.M. Henderson
Keyword(s):  
Cell Wall ◽  
Cell Wall Synthesis ◽  
Streptococcus Faecalis ◽  
Cell Stability

scholarly journals Direct Interaction of Polar Scaffolding Protein Wag31 with Nucleoid-Associated Protein Rv3852 Regulates Its Polar Localization

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1558
Author(s):  
Rajni Garg ◽  
Chinmay Anand ◽  
Sohini Ganguly ◽  
Sandhya Rao ◽  
Rinkee Verma ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Envelope ◽  
Transmembrane Helix ◽  
Ectopic Expression ◽  
Direct Interaction ◽  
Fine Tuning ◽  
Scaffolding Protein ◽  
Physical Interaction ◽  
Cell Wall Synthesis ◽  
Interaction Approach

Rv3852 is a unique nucleoid-associated protein (NAP) found exclusively in Mycobacterium tuberculosis (Mtb) and closely related species. Although annotated as H-NS, we showed previously that it is very different from H-NS in its properties and is distinct from other NAPs, anchoring to cell membrane by virtue of possessing a C-terminal transmembrane helix. Here, we investigated the role of Rv3852 in Mtb in organizing architecture or synthesis machinery of cell wall by protein–protein interaction approach. We demonstrated a direct physical interaction of Rv3852 with Wag31, an important cell shape and cell wall integrity determinant essential in Mtb. Wag31 localizes to the cell poles and possibly acts as a scaffold for cell wall synthesis proteins, resulting in polar cell growth in Mtb. Ectopic expression of Rv3852 in M. smegmatis resulted in its interaction with Wag31 orthologue DivIVAMsm. Binding of the NAP to Wag31 appears to be necessary for fine-tuning Wag31 localization to the cell poles, enabling complex cell wall synthesis in Mtb. In Rv3852 knockout background, Wag31 is mislocalized resulting in disturbed nascent peptidoglycan synthesis, suggesting that the NAP acts as a driver for localization of Wag31 to the cell poles. While this novel association between these two proteins presents one of the mechanisms to structure the elaborate multi-layered cell envelope of Mtb, it also exemplifies a new function for a NAP in mycobacteria.

scholarly journals Effects of Temperature on Anoplophora chinensis (Coleoptera: Cerambycidae) Adult Survival, Reproduction, and Egg Hatch

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 432 ◽  
Author(s):  
Melody A. Keena ◽  
Paul M. Moore ◽  
Gregg Bradford
Keyword(s):  
Invasive Species ◽  
Tree Species ◽  
Adult Survival ◽  
Optimum Temperature ◽  
Egg Hatch ◽  
Laboratory Conditions ◽  
Wide Range ◽  
Survival And Reproduction ◽  
Summer Temperatures ◽  
Effects Of Temperature

Anoplophora chinensis (Forster) is an invasive species that can damage many tree species in orchard, urban, and forested habitats. Adult survival, reproduction, and egg hatch of A. chinensis from Italy and China are evaluated at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40 °C) under laboratory conditions. The estimated Tmax for longevity was 42 and 33 °C for females and 42 and 39 °C for males from China and Italy, respectively. The estimated Tmax, Tmin, and optimum temperature for fecundity were 35, 9, and 29 °C, respectively. Females laid eggs at 15–30 °C and eggs hatched at 15–35 °C. Days to first oviposition increased exponentially from 13 days at 30 °C to >300 days near 10 °C. The estimated Tmin for egg hatch was 13 °C, the Tmax at 38 °C, and the optimum 29 °C. Percentage hatch was estimated to be highest at 26 °C and have a Tmax of 31 °C and Tmin of 10 °C. These results indicate that summer temperatures over a wide range of latitudes should support beetle survival and reproduction, but at temperatures ≥35 °C, oviposition ceases, and adult survivorship declines. In addition, females may survive into the fall, but lay fewer eggs that may not hatch. These responses of A. chinensis to temperature can be used for developing phenological models to predict the timing of stages for management or eradication efforts.

scholarly journals The effects of temperature on aberrant ascus frequencies at the Buff locus in Sordaria brevicollis

1975 ◽  
Vol 26 (2) ◽  
pp. 127-135 ◽  
Author(s):  
A. F. Ahmad
Keyword(s):  
Single Point ◽  
Different Temperatures ◽  
Effects Of Temperature

SUMMARYSingle-point crosses using five allelic spore colour mutants at the buff locus were carried out at different temperatures. The data suggest (i) that fixed or preferred opening points in the DNA, required for initiation of recombination events, are available more often at higher than at lower temperatures, (ii) opening points at or beyond both proximal and distal ends of the buff locus respond similarly to variations in temperature, and (iii) the correction pattern seems to be independent of temperature at the buff locus in S. brevicollis.

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