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Research Containing: microorganism

Comprehensive analysis of the skin fungal microbiota of astronauts during a half-year stay at the International Space Station

by on 22 August 2016in Biology & Biotechnology No comment

The International Space Station (ISS) is a huge manned construct located approximately 400 km above the earth and is inhabited by astronauts performing space experiments. Because the station is within a closed microgravity environment, the astronauts are subject to consistent stress. This study analyzed the temporal changes in the skin fungal microbiota of 10 astronauts using pyrosequencing and quantitative PCR assay before, during, and after their stay in the ISS. Lipophilic skin fungi, Malassezia predominated most samples regardless of the collection period, body site (cheek or chest), or subject. During their stay in the ISS, the level of Malassezia colonization changed by 7.6- +/- 7.5-fold (mean +/- standard deviation) and 9.5- +/- 24.2-fold in cheek and chest samples, respectively. At the species level, M. restricta, M. globosa, and M. sympodialis were more abundant. In the chest samples, the ratio of M. restricta to all Malassezia species increased, whereas it did not change considerably in cheek samples. Fungal diversity was reduced, and the ratio of Malassezia to all fungal colonization increased during the astronauts’ stay at the ISS. The ascomycetous yeast Cyberlindnera jadinii was detected in abundance in the in-flight sample of 5 of the 10 astronauts. The microorganism may have incidentally adhered to the skin during the preflight period and persisted on the skin thereafter. This observation suggests the ability of a specific or uncommon microorganism to proliferate in a closed environment. Our study is the first to reveal temporal changes in the skin fungal microbiota of ISS astronauts. These findings will provide information useful for maintaining the health of astronauts staying in the space environment for long periods and for preventing infection due to the human skin microbiota.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26773135

Impact of space flight on bacterial virulence and antibiotic susceptibility

by on 22 August 2016in Biology & Biotechnology No comment

Manned space flight induces a reduction in immune competence among crew and is likely to cause deleterious changes to the composition of the gastrointestinal, nasal, and respiratory bacterial flora, leading to an increased risk of infection. The space flight environment may also affect the susceptibility of microorganisms within the spacecraft to antibiotics, key components of flown medical kits, and may modify the virulence characteristics of bacteria and other microorganisms that contaminate the fabric of the International Space Station and other flight platforms. This review will consider the impact of true and simulated microgravity and other characteristics of the space flight environment on bacterial cell behavior in relation to the potential for serious infections that may appear during missions to astronomical objects beyond low Earth orbit.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26251622

Three-dimensional structure of phosphoribosyl pyrophosphate synthetase from E. coli at 2.71 Å resolution

by on 22 August 2016in Biology & Biotechnology No comment

Phosphoribosyl pyrophosphate synthetase from Escherichia coli was cloned, purified, and crystal- lized. Single crystals of the enzyme were grown under microgravity. The X-ray diffraction data set was col- lected at the Spring-8 synchrotron facility and used to determine the three-dimensional structure of the enzyme by the molecular-replacement method at 2.71 Å resolution. The active and regulatory sites in the molecule of E. coli phosphoribosyl pyrophosphate synthetase were revealed by comparison with the homol- ogous protein from Bacillus subtilis, the structure of which was determined in a complex with functional ligands. The conformations of polypeptide-chain fragments surrounding and composing the active and reg- ulatory sites were shown to be identical in both proteins.

Related URLs:
http://link.springer.com/article/10.1134%2FS1063774516010247

Diversity of Bacteria of the Genus Bacillus on Board of International Space Station

by on 22 August 2016in Biology & Biotechnology No comment

From swabs of surfaces of equipment and air samples of the Russian segment of the International Space Station, nine strains of spore-forming bacteria of the genus Bacillus belonging to the species B. pumilus, B. licheniformis, B. subtilis, B. megaterium, and B. amyloliquefaciens were isolated. The last species of bacilli on the equipment of RS ISS was detected for the first time. For these species of bacilli, there are known strains that can be opportunistic to humans, and their metabolites can cause biodegradation of equipment and materials. B. pumilus found on ISS belongs to the group of bacteria that exhibits a particularly high resistance to adverse environmental conditions, such as dehydration, ultraviolet and gamma radiation, and chemical disinfection.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26728721

Growth of 48 built environment bacterial isolates on board the International Space Station (ISS)

by on 22 August 2016in Biology & Biotechnology No comment

Background. While significant attention has been paid to the potential risk of pathogenic microbes aboard crewed spacecraft, the non-pathogenic microbes in these habitats have received less consideration. Preliminary work has demonstrated that the interior of the International Space Station (ISS) has a microbial community resembling those of built environments on Earth. Here we report the results of sending 48 bacterial strains, collected from built environments on Earth, for a growth experiment on the ISS. This project was a component of Project MERCCURI (Microbial Ecology Research Combining Citizen and University Researchers on ISS). Results. Of the 48 strains sent to the ISS, 45 of them showed similar growth in space and on Earth using a relative growth measurement adapted for microgravity. The vast majority of species tested in this experiment have also been found in culture-independent surveys of the ISS. Only one bacterial strain showed significantly different growth in space. Bacillus safensis JPL-MERTA-8-2 grew 60% better in space than on Earth. Conclusions. The majority of bacteria tested were not affected by conditions aboard the ISS in this experiment (e.g., microgravity, cosmic radiation). Further work on Bacillus safensis could lead to interesting insights on why this strain grew so much better in space.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/27019789

Purification, crystallization, and preliminary X-ray diffraction study of purine nucleoside phosphorylase from E. coli

by on 22 August 2016in Biology & Biotechnology No comment

Crystals of E. coli purine nucleoside phosphorylase were grown in microgravity by the capillary counter-diffusion method through a gel layer. The X-ray diffraction data set suitable for the determination of the three-dimensional structure at atomic resolution was collected from one crystal at the Spring-8 synchro- tron facility to 0.99 Å resolution. The crystals belong to sp. gr. P21 and have the following unit-cell parameters: a=74.1Å,b=110.2Å,c=88.2Å,α=γ=90°,β=111.08°.Thecrystalcontainssixsubunitsoftheenzyme comprising a hexamer per asymmetric unit. The hexamer is the biological active form of E. coli. purine nucle- oside phosphorylase.

Related URLs:
https://www.researchgate.net/publication/281874019_Purification_Crystallization_and_Preliminary_X-ray_Diffraction_Study_of_Purine_Nucleoside_Phosphorylase_from_E-coli

Study of initial colonization by environmental microorganisms in the Russian segment of the International Space Station (ISS)

by on 9 June 2015in Biology & Biotechnology No comment

In this report, we describe the initial colonization of environmental microorganisms associated with ISS on four different materials (Nomex, cable labeling material, printed circuit board and aluminum), which are commonly used at the ISS. Material substrates were placed in the Russian segment of the ISS in a ‘Target Book’ for 135 days. After the incubation, the ‘Target Book’ was analyzed on Earth by determining colony forming units and identifying the microorganisms by rRNA gene sequencing. The highest cell concentrations and widest biological diversity were on the polymer materials as Nomex and cable labeling material. Additional molecular biological identification revealed the following organisms as typical pioneer microorganisms: Staphylococcus spp., Bacillus spp., Streptococcus spp., Cladosporium spp., Sphingomonas spp., Micrococcus luteus and Stenotrophomonas maltophilia.

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Microbial contamination monitoring and control during human space missions

by on 9 June 2015in Biology & Biotechnology No comment

The ubiquity and resilience of microorganisms makes them unavoidable in most environments including space habitats. The impaired immune system of astronauts in flight raises the level of concern about disease risk during human space missions and additionally these biological contaminants may affect life support systems and hardware. In this review, the microbial contamination observed in manned space stations and in particular the International Space Station ISS will be discussed, demonstrating that it is a microbiologically safe working and living habitat. Microbial contamination levels were in general below the implemented quality standards, although, occasional contamination hazard reports indicate that the current prevention and monitoring strategies are the strict minimum.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0032063311002765

International Space Station environmental microbiome — microbial inventories of ISS filter debris

by on 9 June 2015in Biology & Biotechnology No comment

Despite an expanding array of molecular approaches for detecting microorganisms in a given sample, rapid and robust means of assessing the differential viability of the microbial cells, as a function of phylogenetic lineage, remain elusive. A propidium monoazide (PMA) treatment coupled with downstream quantitative polymerase chain reaction (qPCR) and pyrosequencing analyses was carried out to better understand the frequency, diversity, and distribution of viable microorganisms associated with debris collected from the crew quarters of the International Space Station (ISS). The cultured bacterial counts were more in the ISS samples than cultured fungal population. The rapid molecular analyses targeted to estimate viable population exhibited 5-fold increase in bacterial (qPCR-PMA assay) and 25-fold increase in microbial (adenosine triphosphate assay) burden than the cultured bacterial population. The ribosomal nucleic acid-based identification of cultivated strains revealed the presence of only four to eight bacterial species in the ISS samples, however, the viable bacterial diversity detected by the PMA-pyrosequencing method was far more diverse (12 to 23 bacterial taxa) with the majority consisting of members of actinobacterial genera (Propionibacterium, Corynebacterium) and Staphylococcus. Sample fractions not treated with PMA (inclusive of both live and dead cells) yielded a great abundance of highly diverse bacterial (94 to 118 taxa) and fungal lineages (41 taxa). Even though deep sequencing capability of the molecular analysis widened the understanding about the microbial diversity, the cultivation assay also proved to be essential since some of the spore-forming microorganisms were detected only by the culture-based method. Presented here are the findings of the first comprehensive effort to assess the viability of microbial cells associated with ISS surfaces, and correlate differential viability with phylogenetic affiliation.

Related URLs:
http://dx.doi.org/10.1007/s00253-014-5650-6

Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses

by on 9 June 2015in Biology & Biotechnology No comment

Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40–90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F “wet” trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis, 1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste subsystem analysis and atmospheric management within the ALS Project.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0273117703012043