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Microbes and Environments

Spyridon Ntougias, Żaneta Polkowska, Sofia Nikolaki, Eva Dionyssopoulou, Panagiota Stathopoulou, Vangelis Doudoumis, Marek Ruman, Katarzyna Kozak, Jacek Namieśnik, George Tsiamis
Two thirds of Svalbard archipelago islands in the High Arctic are permanently covered with glacial ice and snow. Polar bacterial communities in the southern part of Svalbard were characterized using an amplicon sequencing approach. A total of 52,928 pyrosequencing reads were analyzed in order to reveal bacterial community structures in stream and lake surface water samples from the Fuglebekken and Revvatnet basins of southern Svalbard. Depending on the samples examined, bacterial communities at a higher taxonomic level mainly consisted either of Bacteroidetes, Betaproteobacteria, and Microgenomates (OP11) or Planctomycetes, Betaproteobacteria, and Bacteroidetes members, whereas a population of Microgenomates was prominent in 2 samples...
September 30, 2016: Microbes and Environments
Dawoon Jung, Yoshiteru Aoi, Slava S Epstein
Standard cultivation fails to grow most microorganisms, whereas in situ cultivation allows for the isolation of comparatively diverse and novel microorganisms. Information on similarities and differences in the physiological properties of isolates obtained from in situ cultivation and standard cultivation is limited. Therefore, we used the arctic sediment samples and compared two culture collections obtained using standard and novel cultivation techniques. Even though there was no temperature selection at the isolation step, isolates from each method showed different reactions to temperature...
September 29, 2016: Microbes and Environments
Cheng-Tai Huang, Chi-Te Liu, Shiang-Jiuun Chen, Wen-Yuan Kao
Crotalaria zanzibarica is an exotic and widely distributed leguminous plant in Taiwan. The relationship between C. zanzibarica and its rhizobial symbionts has been suggested to contribute to its successful invasion. A rhizobial strain (designed as CzR2) isolated from the root nodules of C. zanzibarica and cultivated in standard YEM medium displayed pleomorphism, with cells ranging between 2 and 10 μm in length and some branching. In the present study, we identified this rhizobial strain, investigated the causes of pleomorphism, and examined the nodules formed...
September 29, 2016: Microbes and Environments
Minenosuke Matsutani, Hideki Hirakawa, Eri Hiraoka, Gunjana Theeragool, Toshiharu Yakushi, Kazunobu Matsushita
Acetobacter pasteurianus SKU1108 is a typical thermotolerant acetic acid bacterium. In this study, the complete genome sequence of the SKU1108 strain was elucidated, and information on genomic modifications due to the thermal adaptation of SKU1108 was updated. In order to obtain a clearer understanding of the genetic background responsible for thermotolerance, the SKU1108 genome was compared with those of two closely related complete genome strains, thermotolerant A. pasteurianus 386B and mesophilic A. pasteurianus NBRC 3283...
September 24, 2016: Microbes and Environments
Martina Cappelletti, Daniele Ghezzi, Davide Zannoni, Bruno Capaccioni, Stefano Fedi
"Terre Calde di Medolla" (TCM) (literally, "Hot Lands of Medolla") refers to a farming area in Italy with anomalously high temperatures and diffuse emissions of biogenic CO2, which has been linked to CH4 oxidation processes from a depth of 0.7 m to the surface. We herein assessed the composition of the total bacterial community and diversity of methane-oxidizing bacteria (MOB) in soil samples collected at a depth at which the peak temperature was detected (0.6 m). Cultivation-independent methods were used, such as: i) a clone library analysis of the 16S rRNA gene and pmoA (coding for the α-subunit of the particulate methane monooxygenase) gene, and ii) Terminal Restriction Fragment Length Polymorphism (T-RFLP) fingerprinting...
September 17, 2016: Microbes and Environments
Emilie Portier, Joanne Bertaux, Jérôme Labanowski, Yann Hechard
Legionella pneumophila is a pathogenic bacteria found in biofilms in freshwater. Iron is an essential nutrient for L. pneumophila growth. In this study, complex biofilms were developed using river water spiked with L. pneumophila, and the persistence of L. pneumophila in these complex biofilms was evaluated. In order to study the role of iron in the persistence of L. pneumophila, river water was supplied with either iron pyrophosphate or iron chelators (deferoxamine mesylate, DFX for ferric iron and dipyridyl, DIP for ferrous iron) to modulate iron availability...
September 14, 2016: Microbes and Environments
Makoto Ikenaga, Masakazu Tabuchi, Tomohiro Kawauchi, Masao Sakai
The simultaneous extraction of host plant DNA severely limits investigations of the community structures of plant-associated fungi due to the similar homologies of sequences in primer-annealing positions between fungi and host plants. Although fungal-specific primers have been designed, plant DNA continues to be excessively amplified by PCR, resulting in the underestimation of community structures. In order to overcome this limitation, locked nucleic acid (LNA) primers and PCR clamping by LNA oligonucleotides have been applied to enhance the amplification of fungal internal transcribed spacer (ITS) regions...
September 29, 2016: Microbes and Environments
Dongyan Liu, Kanako Tago, Masahito Hayatsu, Takeshi Tokida, Hidemitsu Sakai, Hirofumi Nakamura, Yasuhiro Usui, Toshihiro Hasegawa, Susumu Asakawa
Elevated concentrations of atmospheric CO2 ([CO2]) enhance the production and emission of methane in paddy fields. In the present study, the effects of elevated [CO2], elevated temperature (ET), and no nitrogen fertilization (LN) on methanogenic archaeal and methane-oxidizing bacterial community structures in a free-air CO2 enrichment (FACE) experimental paddy field were investigated by PCR-DGGE and real-time quantitative PCR. Soil samples were collected from the upper and lower soil layers at the rice panicle initiation (PI) and mid-ripening (MR) stages...
September 29, 2016: Microbes and Environments
Makoto Matsushita, Shugo Ishikawa, Kazushige Nagai, Yuichiro Hirata, Kunio Ozawa, Satoshi Mitsunobu, Hiroyuki Kimura
Accretionary prisms are mainly composed of ancient marine sediment scraped from the subducting oceanic plate at a convergent plate boundary. Large amounts of anaerobic groundwater and natural gas, mainly methane (CH4) and nitrogen gas (N2), are present in the deep aquifers associated with an accretionary prism; however, the origins of these gases are poorly understood. We herein revealed regional variations in CH4 and N2 production processes in deep aquifers in the accretionary prism in Southwest Japan, known as the Shimanto Belt...
September 29, 2016: Microbes and Environments
Masahiro Mitsuboshi, Yuuzou Kioka, Katsunori Noguchi, Susumu Asakawa
Soil-borne diseases caused by pathogenic microorganisms are one of the main factors responsible for the decline in crop yields in farmlands. Pathogenic Fusarium oxysporum causes serious damage to various crops, and, thus, a feasible diagnostic method for soil-borne diseases is required. We herein examined a simple method to evaluate the suppressiveness of soil microorganisms against a pathogen by co-cultivating indigenous soil microorganisms and a pathogenic fungus (F. oxysporum f. sp. spinaciae). We inoculated F...
September 29, 2016: Microbes and Environments
Yohanna Sarria-Guzmán, Yosef Chávez-Romero, Selene Gómez-Acata, Joaquín Adolfo Montes-Molina, Eleacin Morales-Salazar, Luc Dendooven, Yendi E Navarro-Noya
Plant-associated microbes have specific beneficial functions and are considered key drivers for plant health. The bacterial community structure of healthy Anthurium andraeanum L. plants was studied by 16S rRNA gene pyrosequencing associated with different plant parts and the rhizosphere. A limited number of bacterial taxa, i.e., Sinorhizobium, Fimbriimonadales, and Gammaproteobacteria HTCC2089 were enriched in the A. andraeanum rhizosphere. Endophytes were more diverse in the roots than in the shoots, whereas all shoot endophytes were found in the roots...
September 29, 2016: Microbes and Environments
Cláudia S L Vicente, Sota Ozawa, Koichi Hasegawa
Cockroaches are parasitized by thelastomatid nematodes, which live in an obligate manner in their hindgut and interact with the resident microbial community. In the present study, a composition analysis was performed on the gut microbiome of Periplaneta fuliginosa and P. americana to investigate natural and artificial infection by thelastomatid nematodes. Nine libraries of the 16S rRNA gene V3-V4 region were prepared for pyrosequencing. We examined the complete gut microbiome (fore-, mid-, and hindgut) of lab-reared P...
September 29, 2016: Microbes and Environments
Setsuko Hirose, Katsumi Matsuura, Shin Haruta
The diversity of aerobic anoxygenic phototrophic (AAP) bacteria in freshwater environments, particularly in rivers, has not been examined in as much detail as in ocean environments. In the present study, we investigated the phylogenetic and physiological diversities of AAP bacteria in biofilms that developed on submerged stones in a freshwater river using culture methods. The biofilms collected were homogenized and inoculated on solid media and incubated aerobically in the dark. Sixty-eight red-, pink-, yellow-, orange-, or brown-colored colonies were isolated, and, of these, 28 isolates contained the photosynthetic pigment, bacteriochlorophyll (BChl) a...
September 29, 2016: Microbes and Environments
Takashi Narihiro, Masaru K Nobu, Hideyuki Tamaki, Yoichi Kamagata, Yuji Sekiguchi, Wen-Tso Liu
The syntrophic degradation of branched-chain fatty acids (BCFAs) such as 2-methylbutyrate and isobutyrate is an essential step in the production of methane from proteins/amino acids in anaerobic ecosystems. While a few syntrophic BCFA-degrading bacteria have been isolated, their metabolic pathways in BCFA and short-chain fatty acid (SCFA) degradation as well as energy conservation systems remain unclear. In an attempt to identify these pathways, we herein performed comparative genomics of three syntrophic bacteria: 2-methylbutyrate-degrading "Syntrophomonas wolfei subsp...
September 29, 2016: Microbes and Environments
Tomoyuki Minami, Misue Anda, Hisayuki Mitsui, Masayuki Sugawara, Takakazu Kaneko, Shusei Sato, Seishi Ikeda, Takashi Okubo, Hirohito Tsurumaru, Kiwamu Minamisawa
Methylobacterium inhabits the phyllosphere of a large number of plants. We herein report the results of comparative metagenome analyses on methylobacterial communities of soybean plants grown in an experimental field in Tohoku University (Kashimadai, Miyagi, Japan). Methylobacterium was identified as the most dominant genus (33%) among bacteria inhabiting soybean stems. We classified plant-derived Methylobacterium species into Groups I, II, and III based on 16S rRNA gene sequences, and found that Group I members (phylogenetically close to M...
September 29, 2016: Microbes and Environments
Satoshi Ishii, Kazuki Joikai, Shigeto Otsuka, Keishi Senoo, Satoshi Okabe
Pseudogulbenkiania is a relatively recently characterized genus within the order Neisseriales, class Betaproteobacteria. This genus contains several strains that are capable of anaerobic, nitrate-dependent Fe(II) oxidation (NDFO), a geochemically important reaction for nitrogen and iron cycles. In the present study, we examined denitrification functional gene diversities within this genus, and clarified whether other Pseudogulbenkiania sp. strains perform denitrification and NDFO. Seventy strains were analyzed, including two type strains, a well-characterized NDFO strain, and 67 denitrifying strains isolated from various rice paddy fields and rice-soybean rotation fields in Japan...
September 29, 2016: Microbes and Environments
Yuga Hirakata, Mamoru Oshiki, Kyohei Kuroda, Masashi Hatamoto, Kengo Kubota, Takashi Yamaguchi, Hideki Harada, Nobuo Araki
Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates-ciliates frequently found in anoxic ecosystems-on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i...
September 29, 2016: Microbes and Environments
Yuya Sato, Tomoyuki Hori, Ronald R Navarro, Ryuichi Naganawa, Hiroshi Habe, Atsushi Ogata
The effects of a precipitous decrease in the inlet organic loading rate on sludge reductions and the microbial community in a membrane bioreactor were investigated. The sludge biomass was markedly reduced to 47.4% of the initial concentration (approximately 15,000 mg L(-1)) within 7 d after the organic loading rate was decreased by half (450 to 225 mg chemical oxygen demand L(-1) d(-1)). An analysis of the microbial community structure using high-throughput sequencing revealed an increase in the abundance of facultative predatory bacteria-related operational taxonomic units as well as microorganisms tolerant to environmental stress belonging to the classes Deinococci and Betaproteobacteria...
September 29, 2016: Microbes and Environments
Takashi Okubo, Pongdet Piromyou, Panlada Tittabutr, Neung Teaumroong, Kiwamu Minamisawa
The nitrogen fixation (nif) genes of nodule-forming Bradyrhizobium strains are generally located on symbiosis islands or symbiosis plasmids, suggesting that these genes have been transferred laterally. The nif genes of rhizobial and non-rhizobial Bradyrhizobium strains were compared in order to infer the evolutionary histories of nif genes. Based on all codon positions, the phylogenetic tree of concatenated nifD and nifK sequences showed that nifDK on symbiosis islands formed a different clade from nifDK on non-symbiotic loci (located outside of symbiosis islands and plasmids) with elongated branches; however, these genes were located in close proximity, when only the 1st and 2nd codon positions were analyzed...
September 29, 2016: Microbes and Environments
Subed Chandra Dev Sharma, Cuijie Feng, Jiangwei Li, Anyi Hu, Han Wang, Dan Qin, Chang-Ping Yu
A facultative anaerobic bacterium, designated as strain SCS5, was isolated from the anodic biofilm of a mediator-less microbial fuel cell using acetate as the electron donor and α-FeOOH as the electron acceptor. The isolate was Gram-negative, motile, and shaped as short rods (0.9-1.3 μm in length and 0.4-0.5 μm in width). A phylogenetic analysis of the 16S rRNA, gyrB, and rpoD genes suggested that strain SCS5 belonged to the Aeromonas genus in the Aeromonadaceae family and exhibited the highest 16S rRNA gene sequence similarity (99...
September 29, 2016: Microbes and Environments
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