scholarly journals Ecophysiological responses of two closely related epigean and hypogean Niphargus species to hypoxia and increased temperature: Do they differ?

2021 ◽  
Vol 50 (2) ◽  
pp. 111-120
Author(s):  
Tatjana Simčič ◽  
Boris Sket
Keyword(s):  
Oxygen Consumption ◽  
Antioxidant Activities ◽  
Reductase Activity ◽  
Aquatic Organisms ◽  
Metabolic Potential ◽  
Physiological And Biochemical Characteristics ◽  
Increased Temperature ◽  
Oxygen Conditions ◽  
Glutathione Reductase Activity ◽  
Physiological And Biochemical

Ecological performance of animals depends on physiological and biochemical processes that are adjusted to the environment. The responses to hypoxia or anoxia have been frequently studied in subterranean aquatic organisms in order to find potential adaptations to restrict oxygen conditions occurring in the underground habitats. However, some previous studies have compared phylogenetic distant epigean and hypogean species or the epigean and hypogean populations of the same species due to little chance to compare closely related epigean and hypogean species. Therefore, in this study, we compared the effects of exposure to hypoxia, followed by reoxygenation, and increased temperature on oxygen consumption, potential metabolic activity, and antioxidant activities in closely related epigean and hypogean species: Niphargus zagrebensis and N. stygius. Oxygen consumption of N. stygius increased similarly during post-hypoxic recovery at 10 and 20°C (approx. 5-times), while N. zagrebensis increased its oxygen consumption for 9.7 and 4.4-times at 10 and 20°C, respectively. We observed higher exploitation of metabolic potential for current oxygen consumption during reoxygenation in N. zagrebensis than N. stygius. Exposure to hypoxia and subsequent reoxygenation at 20°C increased catalase (CAT) activity in N. stygius, but not in N. zagrebensis. We observed increased glutathione reductase activity in both Niphargus species. We concluded that respiratory and antioxidant responses to severe hypoxia and increased temperature differed between closely related epigean and hypogean Niphargus species. Hypogean Niphargus species possess physiological and biochemical characteristics that are advantageous in temperature stable subterranean environments which support inhabiting of species that have low energetic demands, while epigean Niphargus species can successfully inhabit specific surface habitats.

scholarly journals In Vivo Bioavailability of Selenium in Selenium-Enriched Streptococcus thermophilus and Enterococcus faecium in CD IGS Rats

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 463
Author(s):  
Gabriela Krausova ◽  
Antonin Kana ◽  
Marek Vecka ◽  
Ivana Hyrslova ◽  
Barbora Stankova ◽  
...  
Keyword(s):  
Glutathione Reductase ◽  
Enterococcus Faecium ◽  
Reductase Activity ◽  
Streptococcus Thermophilus ◽  
Heart Tissue ◽  
Sprague Dawley ◽  
Glutathione Reductase Activity ◽  
Novel Concept ◽  
The Individual

The selenium (Se) enrichment of yeasts and lactic acid bacteria (LAB) has recently emerged as a novel concept; the individual health effects of these beneficial microorganisms are combined by supplying the essential micronutrient Se in a more bioavailable and less toxic form. This study investigated the bioavailability of Se in the strains Enterococcus faecium CCDM 922A (EF) and Streptococcus thermophilus CCDM 144 (ST) and their respective Se-enriched forms, SeEF and SeST, in a CD (SD-Sprague Dawley) IGS rat model. Se-enriched LAB administration resulted in higher Se concentrations in the liver and kidneys of rats, where selenocystine was the prevalent Se species. The administration of both Se-enriched strains improved the antioxidant status of the animals. The effect of the diet was more pronounced in the heart tissue, where a lower glutathione reductase content was observed, irrespective of the Se fortification in LAB. Interestingly, rats fed diets with EF and SeEF had higher glutathione reductase activity. Reduced concentrations of serum malondialdehyde were noted following Se supplementation. Diets containing Se-enriched strains showed no macroscopic effects on the liver, kidneys, heart, and brain and had no apparent influence on the basic parameters of the lipid metabolism. Both the strains tested herein showed potential for further applications as promising sources of organically bound Se and Se nanoparticles.

Comparative Characteristics and Desilicon Ability of 10 Strains of Silicate Bacteria Screened from Different Bauxite Ores

2012 ◽  
Vol 524-527 ◽  
pp. 953-956
Author(s):  
Chan Juan Zhong ◽  
De Si Sun ◽  
Hong Bao ◽  
Hao Chen
Keyword(s):  
Henan Province ◽  
Jiangxi Province ◽  
Biochemical Characteristics ◽  
Physiological And Biochemical Characteristics ◽  
Silicate Bacteria ◽  
Bauxite Ore ◽  
Physiological And Biochemical

Ten strains of silicate bacteria were screened from three bauxite samples in Jiangxi Province and Henan Province in China. The ten strains were determined as B. mucilaginosus according to the results of physiological and biochemical characteristics and desilicon ability. Bioleaching tests showed that the ten strains all can decompose bauxite ore and release silicon from bauxite, but had a large difference of desilicon ability among them.

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