scholarly journals The Influence of Starvation and Amino Acids on Metabolism of the Antarctic Amphipod Waldeckia Obesa

2005 ◽  
Vol 25 (2) ◽  
pp. 196-202 ◽  
Author(s):  
T. Janecki ◽  
S. Rakusa-Suszczewski
2013 ◽  
Vol 61 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Vicente Gomes ◽  
Maria José de Arruda Campos Rocha Passos ◽  
Arthur José da Silva Rocha ◽  
Thais da Cruz Alves dos Santos ◽  
Alex Sander Dias Machado ◽  
...  

Changes in environmental factors may deeply affect the energy budget of Antarctic organisms as many of them are stenothermal and/or stenohaline ectotherms. In this context, the aim of this study is to contribute to knowledge on variations in the energy demand of the Antarctic amphipod, Gondogeneia antarctica as a function of temperature and salinity. Experiments were held at the Brazilian Antarctic Station "Comandante Ferraz", under controlled conditions. Animals collected at Admiralty Bay were acclimated to temperatures of 0ºC; 2.5ºC and 5ºC and to salinities of 35, 30 and 25. Thirty measurements were made for each of the nine combinations of the three temperatures and three salinities, totalling 270 measurements. Metabolic rates were assessed by oxygen consumption and total nitrogenous ammonia excretion, in sealed respirometers. When acclimated to salinities 30 or 35, metabolic rates at 0ºC and 2.5ºC were very similar indicating a possible mechanism of metabolic compensation for temperature. At 5.0ºC, however, metabolic rates were always higher. Lower salinities enhanced the effects of temperature on metabolism and ammonia excretion rates. The physiological adaptations of individuals of G. antarctica suggest adaptive mechanisms for energy saving, adjusted to an environment with stable conditions of temperature and salinity. Little is known about the joint effects of salinity and temperature and this study is an important contribution to the understanding of the mechanism of polar organisms in their adaptation to both factors.


2015 ◽  
Vol 24 ◽  
pp. 253-254 ◽  
Author(s):  
Seunghyun Kang ◽  
Sanghee Kim ◽  
Hyun Park

1987 ◽  
Vol 246 (2) ◽  
pp. 295-305 ◽  
Author(s):  
T E Ellingsen ◽  
V Mohr

1. Autoproteolysis post mortem was examined at 0 degree C by following the changes in the major classes of krill (Euphausia superba and Euphausia crystallorophias) proteins and by liberation of peptides and free amino acids, and was based on experiments conducted on board expedition vessels in the Antarctic. 2. Primarily salt-soluble proteins were broken down during the first week of incubation, whereas water-soluble and insoluble proteins were degraded to a much smaller extent. The enzymes responsible for the hydrolysis presumably originate primarily from the digestive apparatus of the krill. 3. In general, the individual amino acids were released at rates corresponding to their relative occurrence in the bulk protein of the krill. Alanine was liberated in larger amounts than would be expected from the composition of the krill protein, and was evidently formed also by reactions other than proteolysis. Glutamic acid, and certain amino acids which presumably occur with high frequency adjacent to glumatic acid residues in the krill protein, were liberated only to a limited extent, and accumulated in smaller peptides. 4. During proteolysis, arginine seemed to be converted to some degree into ornithine, and on prolonged incubation conversion of arginine and lysine into their corresponding decarboxylation products, agmatine and cadaverine, appeared to take place.


2016 ◽  
Vol 3 (7) ◽  
pp. 160106 ◽  
Author(s):  
Masaharu Tsuji

Microbes growing at subzero temperatures encounter numerous growth constraints. However, fungi that inhabit cold environments can grow and decompose organic compounds under subzero temperatures. Thus, understanding the cold-adaptation strategies of fungi under extreme environments is critical for elucidating polar-region ecosystems. Here, I report that two strains of the Antarctic basidiomycetous yeast Mrakia blollopis exhibited distinct growth characteristics under subzero conditions: SK-4 grew efficiently, whereas TKG1-2 did not. I analysed the metabolite responses elicited by cold stress in these two M. blollopis strains by using capillary electrophoresis–time-of-flight mass spectrometry. M. blollopis SK-4, which grew well under subzero temperatures, accumulated high levels of TCA-cycle metabolites, lactic acid, aromatic amino acids and polyamines in response to cold shock. Polyamines are recognized to function in cell-growth and developmental processes, and aromatic amino acids are also known to improve cell growth at low temperatures. By contrast, in TKG1-2, which did not grow efficiently, cold stress strongly induced the metabolites of the TCA cycle, but other metabolites were not highly accumulated in the cell. Thus, these differences in metabolite responses could contribute to the distinct abilities of SK-4 and TKG1-2 cells to grow under subzero temperature conditions.


Hydrobiologia ◽  
1993 ◽  
Vol 262 (2) ◽  
pp. 109-113 ◽  
Author(s):  
Vicente Gomes ◽  
Phan Van Ngan ◽  
Claude de Broyer ◽  
Maria José deA. C. Rocha Passos

1989 ◽  
Vol 1 (4) ◽  
pp. 343-344 ◽  
Author(s):  
C. Oliver Coleman

The family Acanthonotozomatidae is widely distributed, especially in the Antarctic Ocean. Although many acanthonotozomatids are very conspicuous (they are relatively large and often armoured with teeth on tergites and appendages) very little is known about their biology (Just 1978, Coleman 1989).


Sign in / Sign up

Export Citation Format

Share Document