Space Medicine—A Review of Current Concepts

Space medicine deals with the branch of research involved with the adaptation of humans to the unique environment of space. More than 100 people have traveled in space. The day will come when some human beings will spend all their time in space. Medical problems encountered in space, such as motion sickness, negative nitrogen and calcium balance, anemia and radiation exposure, are issues that already affect medical practice outside aerospace medicine.     

The State of the System of Signaling Pattern Recognition Receptors of Monocytes and Granulocytes in the Cosmonauts’ Peripheral Blood before and after Long-Term Flights on Board the International Space Station

The system of signaling pattern recognition receptors was studied in eight cosmonauts at the ages from 35 to 56 years before and after long-term space flights (SFs) on board the International Space Station (ISS). The peripheral blood samples were analyzed for the content of monocytes and granulocytes that express the signaling pattern recognition Toll-like receptors (TLRs) with surface (TLR1, TLR2, TLR4, TLR5, and TLR6) and intracellular (TLR3, TLR8, and TLR9) localization. The serum concentration of basic ligands of TLR2 (HSP60) and TLR4 (HSP70 and HMGB1) were also measured. The results of the studies showed a growth of the HSP60, HSP70, and HMGB1 concentrations on the first day after long-term flight. The increase in the concentration of endogenous ligands was followed by a growth of the number of both monocytes and granulocytes that express the respective pattern recognition receptors, TLR2 and TLR4, in the overwhelming majority of the examined cosmonauts. Thesse relationships suggest that changes in the system of signaling pattern recognition receptors may be due to the prevailing influence of endogenous ligands in response to the effect of long-term spaceflight factors on the human body.     

The Biosynthesis of Low-Molecular-Weight Nitrogen-Containing Secondary Metabolites—Alkaloids—by the Resident Strains of Penicillium chrysogenum and Penicillium expansum Isolated on Board the Mir Space Station

The analysis of the absorption spectra of the low-molecular-weight nitrogen-containing secondary metabolites—alkaloids—of four Penicillium chrysogenum strains and six P. expansum strains isolated on board the Mir space station showed that all these strains synthesize metabolites of alkaloid origin (roquefortine, 3,12-dihydroroquefortine, meleagrin, viridicatin, viridicatol, isorugulosuvin, rugulosuvin B, N acetyltryptamine, and a yellow metabolite containing the benzoquinone chromophore).     

Distribution of environmental performance in life cycle assessments—implications for environmental benchmarking

The International Journal of Life Cycle Assessment - Life cycle assessment (LCA) is considered a robust method to analyse the environmental impacts of products and is used in public and private...     

Distinct signatures of host–microbial meta-metabolome and gut microbiome in two C57BL/6 strains under high-fat diet

A combinatory approach using metabolomics and gut microbiome analysis techniques was performed to unravel the nature and specificity of metabolic profiles related to gut ecology in obesity. This study focused on gut and liver metabolomics of two different mouse strains, the C57BL/6J (C57J) and the C57BL/6N (C57N) fed with high-fat diet (HFD) for 3 weeks, causing diet-induced obesity in C57N, but not in C57J mice. Furthermore, a 16S-ribosomal RNA comparative sequence analysis using 454 pyrosequencing detected significant differences between the microbiome of the two strains on phylum level for Firmicutes, Deferribacteres and Proteobacteria that propose an essential role of the microbiome in obesity susceptibility. Gut microbial and liver metabolomics were followed by a combinatory approach using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and ultra performance liquid chromatography time of tlight MS/MS with subsequent multivariate statistical analysis, revealing distinctive host and microbial metabolome patterns between the C57J and the C57N strain. Many taurine-conjugated bile acids (TBAs) were significantly elevated in the cecum and decreased in liver samples from the C57J phenotype likely displaying different energy utilization behavior by the bacterial community and the host. Furthermore, several metabolite groups could specifically be associated with the C57N phenotype involving fatty acids, eicosanoids and urobilinoids. The mass differences based metabolite network approach enabled to extend the range of known metabolites to important bile acids (BAs) and novel taurine conjugates specific for both strains. In summary, our study showed clear alterations of the metabolome in the gastrointestinal tract and liver within a HFD-induced obesity mouse model in relation to the host–microbial nutritional adaptation.     

Bacterial metabolism of environmental arsenic—mechanisms and biotechnological applications

Arsenic causes threats for environmental and human health in numerous places around the world mainly due to its carcinogenic potential at low doses. Removing arsenic from contaminated sites is hampered by the occurrence of several oxidation states with different physicochemical properties. The actual state of arsenic strongly depends on its environment whereby microorganisms play important roles in its geochemical cycle. Due to its toxicity, nearly all organisms possess metabolic mechanisms to resist its hazardous effects, mainly by active extrusion, but also by extracellular precipitation, chelation, and intracellular sequestration. Some microbes are even able to actively use various arsenic compounds in their metabolism, either as an electron donor or as a terminal electron acceptor for anaerobic respiration. Some microorganisms can also methylate inorganic arsenic, probably as a resistance mechanism, or demethylate organic arsenicals. Bioavailability of arsenic in water and sediments is strongly influenced by such microbial activities. Therefore, understanding microbial reactions to arsenic is of importance for the development of technologies for improved bioremediation of arsenic-contaminated waters and environments. This review gives an overview of the current knowledge on bacterial interactions with arsenic and on biotechnologies for its detoxification and removal.     

Bryozoans and microbial communities of cool-temperate to subtropical latitudes—paleoecological implications

The environmental distribution of encrusting bryozoans settling on disarticulated and living bivalve shells has been recorded from five stations in Japan and New Zealand. Some insight into the observed distribution patterns emerges from information on the interaction of bryozoans with microbial mats. Advancing existing classifications, we have subdivided the encrusting bryozoan morphotypes into seven different growth types that largely reflect the biological potentials of bryozoans in competition for space on substrate surfaces. The frequency distribution of these types (s-/c-/m-/z-laminae, runners, spots, bryostromatolites) reveals the influence of microbial mats as a control factor of bryozoan substrate coverage. Microbial mats in turn are correlated with latitudinal gradients in Japan and New Zealand from cool-temperate to subtropical and tropical waters. Unlike erect bryozoans, laminar ones are probably underrated as facies fossils. Accordingly, laminar bryozoan growth types are reconsidered as a tool for paleoecological interpretation of marine hard substrate communities.     

Pre-harvest retting of flax with glyphosate — Effects of moisture and microbial colonisation on retting

Increasing the frequency of misting of flax plants which had been treated with the herbicide glyphosate also tended to increase the numbers of microbial isolates and increase retting. Fungicides, applied at weekly intervals, suppressed the numbers of fungi but increased the numbers of bacterial isolates; they also decreased retting. Numbers and proportions of fungal isolates varied to some extent with treatment but the spectrum of isolates was relatively constant and appeared little influenced by artificial inoculation. Alternaria alternata was the dominant fungal isolate.     

Ruminal ochratoxin A degradation—Contribution of the different microbial populations and influence of diet

The mycotoxin ochratoxin A (OTA) is degraded extensively in the rumen. In this study, the relative contribution of different rumen microbial populations (MP) and the effect of diet on degradation of OTA were evaluated in a factorial design experiment. Degradation of OTA was quantified by using the Hohenheim gas test (HGT) in vitro fermentation system. Five different HGT diets were used (concentrate:forage proportions (C:F) – 10:90, 30:70, 50:50, 70:30, 90:10), and donor animals were fed diets with the respective ratio. Diets with the highest concentrate content were supplied with and without 10 g/kg sodium bicarbonate (70:30 BC and 90:10 BC). The MP included whole rumen fluid, fungi + protozoa, bacteria + protozoa, protozoa and bacteria + fungi. Protozoa numbers were counted after 24 h and OTA and ochratoxin alpha (OTα) analysed at 0, 4, 8, 12, 24 h. Area under the curve (AUC) and half-life were calculated for the latter two. The short average OTA half-life for whole rumen fluid of 2.6 h (1.3–4.5 h) demonstrates the high OTA degradation capacity of the rumen MP (i.e., standard HGT inoculum) and corresponds well with published in vivo results. Both MP and diet affected OTA degradation. Interactions among factors occurred (P<0.001), which made it necessary to do further comparisons within factor levels. Among MP, those with bacteria (bacteria + fungi and bacteria + protozoa) had lower AUC values (P<0.001) for OTA (196–673 ng/ml h, meaning higher degradation capacity, than those without bacteria (fungi + protozoa and protozoa; 701–1206 ng/ml h). Whole rumen fluid had the lowest AUC values (146–249 ng/ml h; P<0.05). Diet had a quadratic effect (P=0.001) on protozoal numbers with minimum values for the lowest and highest C:F ratios, for bacteria + protozoa, fungi + protozoa and protozoa, but no corresponding effect was found for OTA degradation parameters. While the generally high capacity to degrade OTA was confirmed, results for the contribution of different microbial groups shed new light on ruminal OTA degradation.     

Anaerobic microbial dehalogenation of organohalides — state of the art and remediation strategies

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Investigation on rate — Determining factors in the microbial reduction of azo dyes

Summary Investigations on the effects of pH, temperature, type and concentration of respiration substrates and oxygen tension on the reduction rate of derivatives of 1-phenylazo-2-naphthol and of a variety of textile dyes served as a basis for establishing a bioassay for strictly reproducible measurements of the microbial reduction rate of azo dyes. Standard organism was a strain of Bacillus cereus isolated from soil. Dye reduction occurred with the standard organism and other facultatively or obligatory aerobic bacteria in exclusively anoxic conditions. In principle, first order kinetics of decolorization were found. Reduction products may however inhibit the reaction. All dyes not measurably reduced by living cells of B. cereus were decolorized by cell extracts of the same species. Dyes adsorbed by the cell walls were in most cases reduced at slow rates and did not influence the simultaneous reduction of non-adsorbable dyes in the medium. The observations confirm the hypothesis advanced by Gingell and Walker (1971) of an intracellular, non-enzymatic reduction of azo compounds by reduced flavin nucleotides. The rate of permeation of the dyes through the cell membrane is the primordial ratelimiting step in the microbial decolorization of azo dyes. Sulfonic acid substitution seems to be an effective inhibitor of permeation.     

Degradation of wheat straw by a microbial community —stimulation by a polysaccharidase complex

Laboratory-scale reactors were used to watch aspects of biodegradation of wheat straw when supplemented with polysaccharidases (Czym) to increase the enzyme production of microorganisms involved during a composting process for mushroom production. Biochemical and biological parameters were tested both under aerobic and O₂-limited conditions to assess degradability. These were measurement of released CO₂ and NH₃, determination of neutral detergent fibre content and cellulase activities from compost extract. The addition of Czym to decomposing straw had three consequences: (i) it supplied and released low quantities of readily available sugars; (ii) it increased the cellulase activities in the substrates; (iii) it increased the number of bacteria under aerobic conditions. The three effects were linked and the small quantity of sugars released by the addition of Czym may have acted as an activator of bacterial activities through an inductive mechanism. Correspondence to: S. Libmond     

Performance of a filter loop reactor using Zymomonas mobilis and validation of the ethanol production model — II

A special loop recycle reactor with capillary crossflow filters was designed to enhance ethanol productivity. The new set-up did not comprise a classical reaction vessel with a stirrer but the working volume consisted only of the void volumes of the filters and the peripheral equipment, however, it behaved as a well mixed CSTR. A circulating pump provided for both mixing and recirculation of the culture fluid. Degassing was accomplished with a cyclone type device. Even if the circulating pump destroyed cells and automated backflushing of the filters could not prevent membrane fouling, maximum biomass concentration reached 98 g l⁻¹ at a dilution rate of 4 h⁻¹ and the maximum ethanol productivity achieved was 224 g l⁻¹ h⁻¹. Using the loop recycle reactor, the ethanol production model proposed in Part I of this study (Nipkow et al. (1986) J. Biotechnol. 3, 35–47) extended with a variable rate accounting for mechanical destruction of cells was verified. It was demonstrated that the predicted productivity of 350 g l⁻¹ h⁻¹ — exploiting the biological potential of Zymomonas mobilis — should be attainable if improved mechanical equipment in a filter recycle system is employed.     

Books from an environmental perspective—Part 1: environmental impacts of paper books sold in traditional and internet bookshops

Purpose  

The sale and distribution of books are activities that have changed through increased use of the internet. The main aim of this paper was to determine the potential environmental impacts of paper books and identify key issues determining the magnitude of those impacts. A second aim was to study the environmental difference between a paper book bought in a traditional bookshop and through an internet bookshop. In addition, areas with a lack of data and major uncertainties were to be noted.