Novel insights into the diversity of catabolic metabolism from ten haloarchaeal genomes

Background

The extremely halophilic archaea are present worldwide in saline environments and have important biotechnological applications. Ten complete genomes of haloarchaea are now available, providing an opportunity for comparative analysis.

Methodology/Principal Findings

We report here the comparative analysis of five newly sequenced haloarchaeal genomes with five previously published ones. Whole genome trees based on protein sequences provide strong support for deep relationships between the ten organisms. Using a soft clustering approach, we identified 887 protein clusters present in all halophiles. Of these core clusters, 112 are not found in any other archaea and therefore constitute the haloarchaeal signature. Four of the halophiles were isolated from water, and four were isolated from soil or sediment. Although there are few habitat-specific clusters, the soil/sediment halophiles tend to have greater capacity for polysaccharide degradation, siderophore synthesis, and cell wall modification. Halorhabdus utahensis and Haloterrigena turkmenica encode over forty glycosyl hydrolases each, and may be capable of breaking down naturally occurring complex carbohydrates. H. utahensis is specialized for growth on carbohydrates and has few amino acid degradation pathways. It uses the non-oxidative pentose phosphate pathway instead of the oxidative pathway, giving it more flexibility in the metabolism of pentoses.

Conclusions

These new genomes expand our understanding of haloarchaeal catabolic pathways, providing a basis for further experimental analysis, especially with regard to carbohydrate metabolism. Halophilic glycosyl hydrolases for use in biofuel production are more likely to be found in halophiles isolated from soil or sediment.     

The tetraethylammonium salt of monensic acid—An antidote for subacute cadmium intoxication. A study using an ICR mouse model

In this study, the ability of the chelating agent monensic acid (administered as the tetraethylammonium salt) to reduce the cadmium (Cd) concentration in the kidneys, liver, heart, lungs, spleen and testes of Cd-intoxicated mice was investigated. Chelation therapy with the tetraethylammonium salt of monensic acid led to a significant decrease of the Cd concentration in all of the organs of the Cd-treated mice. This effect varied from 50% in the kidneys to 90% in the hearts of the sacrificed animals (compared to the Cd-treated controls). No redistribution of the toxic metal ions to the brain of the animals as a result of the detoxification with the chelating agent was observed. The detoxification of the animals with the antibiotic salt did not perturb the endogenous levels of copper (Cu) or zinc (Zn). The tetraethylammonium salt of monensic acid significantly ameliorated the Cd-induced total iron (Fe) depletion in the liver and spleen of Cd-treated mice. It also restored to control levels the values of transferrin-bound Fe and the total iron binding capacity (TIBC) of the plasma. These results imply that the tetraethylammonium salt of monensic acid could be an efficient antidote in cases of Cd-intoxication.     

Highly selective trapping of enteropathogenic E. coli on Fabry-Pérot sensor mirrors

A novel strategy for the enhancement of electrochemiluminescence (ECL) was developed by combining CdSe quantum dots (QDs) with graphene oxide-chitosan (GO-CHIT). The ECL sensor fabricated with CdSe QDs/GO-CHIT composite exhibited high ECL intensity, good biocompatibility and long-term stability, and was used to detect of cytochrome C (Cyt C). The results show that the ECL sensor has high sensitivity for Cyt C with the linear range from 4.0 to 324 μM and the detection limit of 1.5 μM. Furthermore, the ECL sensor can selectively sense Cyt C from glucose and bovine serum albumin (BSA).     

A role for the melatonin-related receptor GPR50 in leptin signaling, adaptive thermogenesis, and torpor

The ability of mammals to maintain a constant body temperature has proven to be a profound evolutionary advantage, allowing members of this class to thrive in most environments on earth. Intriguingly, some mammals employ bouts of deep hypothermia (torpor) to cope with reduced food supply and harsh climates [1, 2]. During torpor, physiological processes such as respiration, cardiac function, and metabolic rate are severely depressed, yet the neural mechanisms that regulate torpor remain unclear [3]. Hypothalamic responses to energy signals, such as leptin, influence the expression of torpor [4-7]. We show that the orphan receptor GPR50 plays an important role in adaptive thermogenesis and torpor. Unlike wild-type mice, Gpr50(-/-) mice readily enter torpor in response to fasting and 2-deoxyglucose administration. Decreased thermogenesis in Gpr50(-/-) mice is not due to a deficit in brown adipose tissue, the principal site of nonshivering thermogenesis in mice [8]. GPR50 is highly expressed in the hypothalamus of several species, including man [9, 10]. In line with this, altered thermoregulation in Gpr50(-/-) mice is associated with attenuated responses to leptin and a suppression of thyrotropin-releasing hormone. Thus, our findings identify hypothalamic circuits involved in torpor and reveal GPR50 to be a novel component of adaptive thermogenesis in mammals.     

The effect of unconscious color hue saturation on emotional state of human

The aim of the study was to investigate influence of color hue saturation on emotional state of human. We use frontal EEG asymmetry to determine subject's emotional state. Our emotional stimuli summon opposite dynamics of frontal EEG asymmetry. Negative stimuli elicits decreasing of the value of frontal EEG asymmetry and positive stimuli increases the value of frontal EEG asymmetry in fronto-polar and frontal leads. Such dynamics of frontal EEG asymmetry point the emotional experience in accordance the stimulus modality. Blue and red color modification of stimuli leads changes in dynamics of frontal EEG asymmetry during presentation of emotional stimuli and after. In fact, that no one subject gave a report about color difference between stimuli during an experiment, we conclude that influence of color modification was unconscious. Our result shows the possibility of unconscious perception color modification to emotional state of human.     

Review of the specific effects of microwave radiation on bacterial cells

The aim of the present review was to evaluate the literature suggesting that consideration be given to the existence of specific microwave (MW) effects on prokaryotic microorganisms; that is, effects on organisms that cannot be explained by virtue of temperature increases alone. This review considered a range of the reported effects on cellular components; including membranes, proteins, enzyme activity as well as cell death. It is concluded that the attribution of such effects to non-thermal mechanisms is not justified due to poor control protocols and because of the possibility that an unmeasurable thermal force, relating to instantaneous temperature (T (i)) that occurs during MW processing, has not been taken into account. However, due to this lack of control over T (i), it also follows that it cannot be concluded that these effects are not 'non-thermal'. Due to this ambiguity, it is proposed that internal 'micro'-thermal effects may occur that are specific to MW radiation, given its inherent unusual energy deposition patterning.     

Genetic characterization of wild leguminous nodular bacteria living in the South Urals

Genetic diversity and phylogeny of rhizobia that nodulate 18 species of wild-growing bean plants of South Urals from 8 genera belonging to 4 tribes (Loteae, Genisteae, Galegeaev and Hedysareae) was studied. It was demonstrated that for the wild-growing plants of Galegeae and Hedysareae tribes symbiotic interaction with various strains of nodule bacteria that closely related to bacteria of Mesorhizobium sp. was typical of the plants of Genisteae tribe--to bacteria of Bradyrhizobium sp. In the nodules of Lortus ucrainicus from Loteae tribe we have found a rhizobium that is closely related to the bacteria of Mesorhizobium sp., and at Coronilla varia rhizobia strains obtained by us were close by sequence of a 16S pRNA gene to Rhizobium sp. In the nodules of some kinds of the investigated plants we found also minor species of a rhizobia, which structure is under the great influence of conditions of the host plant growth.