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Environmental Microbiology Reports

Danilo de Andrade Cavalcante, Marlene Teixeira De-Souza, Juliana Capela de Orem, Maria Inês André de Magalhães, Paulo Henrique Martins, Tyler J Boone, José A Castillo, Adam Driks
Many species in the order Bacillales form a specialized cell type called a spore that is resistant to a range of environmental stresses. Transmission electron microscopy (TEM) reveals that the spore is comprised of a series of concentric shells, surrounding an interior compartment harbouring the spore DNA. The outermost of these shells varies considerably in morphology among species, likely reflecting adaptations to the highly diverse niches in which spores are found. To better characterize the variation in spore ultrastructure among diverse species, we used TEM to analyse spores from a collection of 23 aerobic spore-forming bacteria from the Solo do Distrito Federal (SDF strains), spanning the genera Bacillus, Lysinibacillus, Paenibacillus, and Brevibacillus, isolated from soil from central Brazil...
November 13, 2018: Environmental Microbiology Reports
Shikha Khullar, M Sudhakara Reddy
Ectomycorrhizal fungi play an important role in protecting their host plant from metal(loid) stresses by synthesizing various thiol rich compounds like metallothioneins and glutathione. We investigated the effect of cadmium (Cd) and arsenic (As) stress with a specific interest on glutathione (GSH) in the ectomycorrhizal fungus Laccaria bicolor. The total GSH levels inside the cell were significantly increased with increase in external metal(loid) stress. An analysis of the transcript levels of genes responsible for GSH synthesis, γ-glutamylcysteinesynthetase (Lbγ-GCS) and glutathione synthetase (LbGS), using qPCR revealed that expression of both genes increased as a function of external metal(loid) concentration...
November 8, 2018: Environmental Microbiology Reports
Buddhie S Nanayakkara, Claire L O'Brien, David M Gordon
E. coli strains responsible for elevated counts in freshwater reservoirs in Australia carry a capsule originating from Klebsiella. The occurrence of Klebsiella capsules in E. coli was about 7% overall and 23 different capsule types were detected. Capsules were observed in strains from phylogroups A, B1, and C, but were absent from phylogroup B2, D, E, and F strains. In general, few A, B1, or C lineages were capsule-positive, but when a lineage was encapsulated multiple different capsule types were present. All Klebsiella capsule-positive strains were of serogroups O8, O9, and O89...
November 8, 2018: Environmental Microbiology Reports
Anja Spang, Pierre Offre
In this crystal ball, we discuss emerging methodologies that can help reaching a synthesis on the biodiversity of Archaea and Bacteria and thereby inform a central enigma in microbiology, i.e. the fundamental split between these primary domains of life and the apparent lower diversity of the Archaea.
November 5, 2018: Environmental Microbiology Reports
Elisabetta Zanardini, Eric May, Kevin J Purdy, J Colin Murrell
Previous studies on microbes associated with deterioration of cultural heritage (CH) stoneworks have revealed a diverse microbiota adapted to stresses such as low nutrients, aridity and high salinity, temperatures and radiation. However, the function of these pioneer microbial communities is still unclear. This study examines bacterial and archaeal diversity in exfoliated and dark encrustation sandstone from Portchester Castle (UK) by 16S rRNA and functional gene analyses. Bacterial and archaeal communities from the exfoliated sites were distinctly different from the dark encrustation...
October 22, 2018: Environmental Microbiology Reports
Tania Henríquez, Nicola Victoria Stein, Heinrich Jung
Fluorescent pseudomonads produce and secrete a siderophore termed pyoverdine to capture iron when it becomes scarce. The molecular basis of pyoverdine secretion is only partially understood. Here, we investigate the role of the putative PvdRT-OpmQ and MdtABC-OpmB efflux systems in pyoverdine secretion in the soil bacterium Pseudomonas putida KT2440. Expression from the respective promoters is stimulated by iron limitation albeit to varying degrees. Deletion of pvdRT-opmQ leads to reduced amounts of pyoverdine in the medium and decreased growth under iron limitation...
October 22, 2018: Environmental Microbiology Reports
Yosia Mukasa, Samuel Kyamanywa, Julius P Sserumaga, Michael Otim, Venansio Tumuhaise, Mark Erbaugh, James P Egonyu
This study isolated and evaluated virulence of fungal entomopathogens of Xylosandrus compactus-an important pest of Robusta coffee in Sub-Saharan Africa. A survey was conducted in five farming systems in Uganda to isolate entomopathogens associated with X. compactus. Four fungal isolates were screened for virulence against X. compactus in the laboratory at 1 x 107 conidia/ml where an atoxigenic L-strain of A. flavus killed 70-100% of all stages of X. compactus compared to other unidentified isolates which caused 20-70% mortalities...
October 11, 2018: Environmental Microbiology Reports
Mia Terashima, Keisuke Ohashi, Taichi E Takasuka, Hisaya Kojima, Manabu Fukui
Hymenobacter nivis P3T is a heterotrophic bacterium isolated from Antarctic red snow generated by algal blooms. Despite being non-photosynthetic, H. nivis was dominantly found in the red snow environment that is exposed to high light and UV irradiation, suggesting that this species can flourish under such harsh conditions. In order to further understand the adaptive strategies on the snow surface environment of Antarctica, the genome of H. nivis P3T was sequenced and analyzed, which identified genes putatively encoding for light-reactive proteins such as proteorhodopsin, phytochrome, photolyase and several copies of cryptochromes...
October 9, 2018: Environmental Microbiology Reports
Isotta D'Arrigo, João G R Cardoso, Maja Rennig, Nikolaus Sonnenschein, Markus J Herrgård, Katherine S Long
Pseudomonas putida is characterized by a versatile metabolism and stress tolerance traits that allow the bacterium to cope with different environmental conditions. In this work, the mechanisms that allow P. putida KT2440 to grow in the presence of four sole carbon sources (glucose, citrate, ferulic acid, serine) were investigated by RNA sequencing (RNA-seq) and genome-scale metabolic modeling. Transcriptomic data identified uptake systems for the four carbon sources, and candidates were subjected to preliminary experimental characterization by mutant strain growth to test their involvement in substrate assimilation...
October 9, 2018: Environmental Microbiology Reports
Simon Roux, Jennifer R Brum
No abstract text is available yet for this article.
October 8, 2018: Environmental Microbiology Reports
Karen K Dittmann, Eva C Sonnenschein, Suhelen Egan, Lone Gram, Mikkel Bentzon-Tilia
Bacteria-host interactions are universal in nature and have significant effects on host functionality. Bacterial secondary metabolites are believed to play key roles in such interactions as well as in interactions within the host-associated microbial community. Hence, prominent secondary metabolite-producing bacteria may be strong drivers of microbial community composition in natural host-associated microbiomes. This has however not been rigorously tested, and the purpose of this study was to investigate how the secondary metabolite producer Phaeobacter inhibens affects the diversity and composition of microbiomes associated with the microalga Emiliania huxleyi and the European flat oyster, Ostrea edulis...
October 2, 2018: Environmental Microbiology Reports
Nannan Wang, Ya-Wei Luo, Luca Polimene, Rui Zhang, Qiang Zheng, Ruanhong Cai, Nianzhi Jiao
The origin of the recalcitrant dissolved organic carbon (RDOC) reservoir in the deep ocean remains enigmatic. The structural recalcitrance hypothesis suggests that RDOC is formed by molecules that are chemically resistant to bacterial degradation. The dilution hypothesis claims that RDOC is formed from a large diversity of labile molecules that escape bacterial utilization due to their low concentrations, termed as RDOCc . To evaluate the relative contributions of these two mechanisms in determining the long-term persistence of RDOC, we model the dynamics of both structurally recalcitrant DOC and RDOCc based on previously published data that describes deep oceanic DOC degradation experiments...
October 2, 2018: Environmental Microbiology Reports
Miguel Ballen-Segura, Jordi Catalan, Marisol Felip
The verification that many phytoflagellates ingest prokaryotes has changed the view of the microbial loop in aquatic ecosystems. Still, progress is limited because the phagotrophic activity is difficult to quantify in natural assemblages. Linking the food vacuole content in protist with the ingestion rate of prokaryotes would provide a crucial step forward. In this study, using the catalysed reporter deposition - fluorescence in situ hybridization protocol (CARD-FISH), which allows the visualization of labelled prokaryotes inside protists without relying on incubation procedures, we experimentally relate the food vacuole content of prokaryotes (Vc ) to the population-averaged ingestion rates (Ir ) estimated using bacteria-size fluorescent microspheres...
September 26, 2018: Environmental Microbiology Reports
Jorge Antunes, Pedro Leão, Vitor Vasconcelos
Surfaces immersed in seawater are rapidly colonized by various microorganisms, resulting in the formation of heterogenic marine biofilms. These communities are known to influence the settlement of algae spores and invertebrate larvae, triggering a succession of fouling events, with significant environmental and economic impacts. This review covers recent research regarding the differences in composition of biofilms isolated from different artificial surface types and the influence of environmental factors on their formation...
September 24, 2018: Environmental Microbiology Reports
Manon T Duret, Richard S Lampitt, Phyllis Lam
Suspended particles are major organic carbon substrates for heterotrophic microorganisms in the mesopelagic ocean (100-1000m). Nonetheless, communities associated with these particles have been overlooked compared to sinking particles, the latter generally considered as main carbon transporters to the deep ocean. This study is the first to differentiate prokaryotic communities associated with suspended and sinking particles, collected with a marine snow catcher at four environmentally distinct stations in the Scotia Sea...
September 24, 2018: Environmental Microbiology Reports
Ilona A Ruhl, Stephen E Grasby, Evan S Haupt, Peter F Dunfield
Microbial species diversity may peak at certain optimal environmental conditions and decrease toward more extreme conditions. Indeed, bell-shaped relationships of species diversity against pH and temperature have been demonstrated, but diversity patterns across other environmental conditions are less well reported. In this study, we investigated the impact of salinity on the diversity of microorganisms from all three domains in a large set of natural springs with salinities ranging from freshwater to halite saturated...
September 24, 2018: Environmental Microbiology Reports
Paul A Kenward, Rachel L Simister, Connor Morgan-Lang, Niko Finke, Arne Sturm, Steven J Hallam, Sean A Crowe
We developed an efficient, scalable, and inexpensive method for recovering cellular biomass from complex fluid matrices that cannot be processed using conventional filtration methods. The method uses chemical flocculation with iron oxyhydroxides, is capable of recovering >90% of cellular biomass from fluids with more than 103 cells ml-1 , and was validated using both mock communities and field samples. High quality DNA can be readily extracted from iron flocs using standard soil extraction kits. We applied chemical flocculation to fracing fluids from British Columbia, Canada, and recovered a diversity of microbial taxa including abundant members of the Epsilon- and Deltaproteobacteria previously recovered from shale gas operations in the United States...
September 19, 2018: Environmental Microbiology Reports
Takashi Narihiro, Masaru K Nobu, Ben T W Bocher, Ran Mei, Wen-Tso Liu
Methanogenic bioreactors have been applied to treat purified terephthalic acid (PTA) wastewater containing complex aromatic compounds, such as terephthalic acid, para-toluic acid and benzoic acid. This study characterized the interaction of microbial populations in 42 samples obtained from 10 PTA-degrading methanogenic bioreactors. Approximately, 54 dominant populations (11 methanogens, 8 syntrophs and 35 functionally unknown clades) that represented 73.9% of total 16S rRNA gene iTag sequence reads were identified...
August 22, 2018: Environmental Microbiology Reports
Raquel Cantos, Jose I Labella, Javier Espinosa, Asunción Contreras
Cyanobacteria, phototrophic organisms performing oxygenic photosynthesis, must adapt their metabolic processes to important environmental challenges, like those imposed by the succession of days and nights. Not surprisingly, certain regulatory proteins are found exclusively in this phylum. One of these unique factors, PipX, provides a mechanistic link between signals of carbon/nitrogen and of energy, transduced by the signalling protein PII, and the control of gene expression by the global nitrogen regulator NtcA...
August 20, 2018: Environmental Microbiology Reports
Lawrence P Wackett
No abstract text is available yet for this article.
October 2018: Environmental Microbiology Reports
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