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Gastrointestinal microorganisms in cats and dogs: a brief review 全文
2013
Garcia-Mazcorro, JF(Universidad Autónoma de Nuevo León Facultad de Medicina Veterinaria y Zootecnia) | Minamoto, Y(Texas A&M University Department of Small Animal Clinical Sciences Gastrointestinal Laboratory)
Gastrointestinal microorganisms in cats and dogs: a brief review 全文
2013
Garcia-Mazcorro, JF(Universidad Autónoma de Nuevo León Facultad de Medicina Veterinaria y Zootecnia) | Minamoto, Y(Texas A&M University Department of Small Animal Clinical Sciences Gastrointestinal Laboratory)
El tracto gastrointestinal (GI) de animales contiene diferentes tipos de microorganismos conocido como la microbiota GI. Por mucho tiempo, la microbiota GI ha generado interés porque los microorganismos GI están involucrados en múltiples procesos fisiológicos en el hospedero, así perpetuando salud o enfermedad. Estudios recientes han demostrado que la microbiota GI de gatos y perros es tan compleja como en humanos y otros animales, revelado con el uso de tecnologías de secuencia modernas y otras técnicas moleculares. La microbiota GI incluye miembros de todos los tres dominios principales de vida (Archaea, Bacterias y Eucariotas), pero las bacterias son el grupo de microorganismos más abundante y metabólicamente activo. El estómago de gatos y perros esta principalmente poblado de Helicobacter spp., el cual en perros puede representar tanto como el 98% de toda la microbiota bacteriana en el estómago. El intestino delgado contiene una microbiota más diversa, conteniendo representantes de al menos cinco diferentes filos bacterianos (principalmente Firmicutes y Bacteroidetes). El intestino grueso contiene el grupo de bacterias más abundante (~10(11) células bacterianas por gramo de contenido intestinal), diverso (al menos diez diferentes filos han sido detectados) y metabólicamente relevante en el tracto GI. La mayoría de las bacterias en el intestino grueso son anaerobios estrictos, los cuales dependen de la fermentación de sustancias no digeridas para subsistir. Aunque estudios recientes han dilucidado las complejidades de la microbiota GI en gatos y perros, más investigación todavía es necesaria para encontrar maneras de manipular exitosamente los microorganismos GI para prevenir y/o tratar enfermedades GI. | The gastrointestinal (GI) tract of animals contains different types of microorganisms known as the GI microbiota. The GI microbiota has long been of interest because of its involvement in multiple physiological processes in the host, influencing health or disease. Recent studies have shown that the GI microbiota of cats and dogs is as complex as the one present in humans and other animals, according to state-of-the-art sequencing technologies and other molecular techniques. The GI microbiota includes members of all three main life domains (Archaea, Bacteria, and Eukaryotes), with bacteria being the most abundant and metabolically active group of microorganisms. The stomach of cats and dogs is mainly inhabited by Helicobacter spp., which in dogs may account for as much as 98% of all gastric bacterial microbiota. The small intestine harbors a more diverse microbiota as it contains representatives from at least five bacterial phyla (mainly Firmicutes and Bacteroidetes). The large intestine harbors the most abundant (~10(11) bacterial cells per gram of intestinal content), diverse (at least 10 bacterial phyla have been identified) and physiologically relevant group of bacteria in the GI tract. Most bacteria in the large intestine are strict anaerobes that depend on fermentation of non-digested dietary substances to subsist. Although recent studies are shedding light into the complexity of the GI microbiota in cats and dogs, further research is needed to find ways to successfully manipulate GI microorganisms to prevent and/or treat GI diseases.
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Microorganisms—A Forum for Understanding Microbial Life in All Its Forms 全文
2013
John Fuerst
Microorganisms—A Forum for Understanding Microbial Life in All Its Forms 全文
2013
John Fuerst
It is my great pleasure to welcome you to Microorganisms, a new open access journal, which is dedicated to microorganisms in all their forms and via any approach to their study. [...]
显示更多 [+] 显示较少 [-]Microorganisms—A Forum for Understanding Microbial Life in All Its Forms 全文
2013
John Fuerst
It is my great pleasure to welcome you to Microorganisms, a new open access journal, which is dedicated to microorganisms in all their forms and via any approach to their study.
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2013
Rosado, Tânia | Gil, Milene | Mirão, José | Candeias, António | Caldeira, Ana Teresa
Oxalate film formation is a pathology that often occurs in mural paintings and may result from the concomitant action of microorganisms and environmental conditions.Low Choir of the Convent of Nossa Senhora da Saudação (Portugal) has mural paintings with an extraordinary beauty, which over time have been suffered polychromy degradation and biofilm formation, presenting an ideal case study to investigate the role and impact of microorganisms in the biodeterioration process.Bacterial populations, filamentous fungi belonging to the genera Cladosporium, Penicillium, Nectria and yeast strain of the genera Rhodotorula were isolated from these wall paintings. The penetration of fungal hyphae in the microstructure of mortars, observed by scanning electron microscopy, seems to be responsible for cracking and detachments in some areas of the painting. The study revealed that the veils on the surface of the paintings are essentially oxalates and that these biofilms are caused by metabolic activity of bacterial communities. Furthermore, the colour alteration of green areas due to microorganisms was detected by Raman microscopy, in real samples and under in vitro conditions, being the result of the metabolic activity of microorganisms present on the paintings, which promote calcium oxalates formation over the malachite paint layers.
显示更多 [+] 显示较少 [-]A Self-Referencing Detection of Microorganisms Using Surface Enhanced Raman Scattering Nanoprobes in a Test-in-a-Tube Platform 全文
2013
Chenxu Yu | Chao Wang | Nan Xiao
Anisotropic nanoparticles (i.e., silver nanocubes) were functionalized with target-specific antibodies and Raman active tags to serve as nanoprobes for the rapid detection of bacteria in a test-in-a-tube platform. A self-referencing scheme was developed and implemented in which surface enhanced Raman spectroscopic (SERS) signatures of the targets were observed superimposed with the SERS signals of the Raman tags. The assessment through the dual signals (superimposed target and tag Raman signatures) supported a specific recognition of the targets in a single step with no washing/separation needed to a sensitivity of 102 CFU/mL, even in the presence of non-target bacteria at a 10 times higher concentration. The self-referencing protocol implemented with a portable Raman spectrometer potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.
显示更多 [+] 显示较少 [-]Life in the ‘charosphere’ – Does biochar in agricultural soil provide a significant habitat for microorganisms? 全文
2013
(Davey L.),
Life in the ‘charosphere’ – Does biochar in agricultural soil provide a significant habitat for microorganisms? 全文
2013
(Davey L.),
Biochar application has become a novel and emergent technology for sequestering C, improving soil quality and crop production, and is a potential win–win strategy for ecosystem service delivery. Biochar addition can also stimulate soil microbial activity, and although it is unclear exactly why biochar should benefit soil microorganisms, it is thought that the large surface area and volume of pores provide a significant habitat for microbes. The aim of this study was to determine the level of microbial colonisation of wood-derived biochar that had been buried in an agricultural soil for three years. We have examined the level of colonisation on the internal and external surfaces of field-aged biochar by scanning electron microscopy, and used 14C-labelled glucose to quantify the rates of microbial activity in different spatial niches of the biochar and the surrounding soil. Microbial colonisation of field-aged biochar was very sparse, with no obvious differences between the external and internal surfaces. At the high field application rate of 50 t ha−1, biochar contributed only 6.52 ± 0.11% of the total soil pore space and 7.35 ± 0.81% of the total soil surface area of the topsoil (0–30 cm). Further, 17.46 ± 0.02% of the biochar pores were effectively uninhabitable for most microbes, being <1 μm in diameter. The initial rate of microbial mineralization of 14C-labelled glucose was significantly greater in the control bulk soil and the soil immediately surrounding the biochar than on the biochar external and internal surfaces. However, lower C use efficiency values of microbes on, or within, the biochar also suggested lower available C status or differences in the structure of the microbial community in the biochar relative to the surrounding soil. This study suggests that, at least in the short term (≤3 y), biochar does not provide a significant habitat for soil microbes. While biochar is extremely recalcitrant and largely unavailable to soil microbes, changes in soil physicochemical properties and the introduction of metabolically available labile compounds into the surrounding soil (the ‘charosphere’) may significantly alter soil microbial activity and structure, which could ultimately affect soil–plant–microbe interactions. Therefore, before the wide-scale application of biochar to agricultural land is exploited, it is important that we understand further how the properties of biochar positively or negatively affect soil microbial communities, and in turn, how they interact with, and colonise biochar.
显示更多 [+] 显示较少 [-]Life in the 'charosphere' - Does biochar in agricultural soil provide a significant habitat for microorganisms? 全文
2013 | 2014
Quilliam, Richard | Glanville, Helen C | Wade, Stephen C | Jones, David L | Biological and Environmental Sciences | Bangor University | Aberystwyth University | Bangor University | 0000-0001-7020-4410
Biochar application has become a novel and emergent technology for sequestering C, improving soil quality and crop production, and is a potential win-win strategy for ecosystem service delivery. Biochar addition can also stimulate soil microbial activity, and although it is unclear exactly why biochar should benefit soil microorganisms, it is thought that the large surface area and volume of pores provide a significant habitat for microbes. The aim of this study was to determine the level of microbial colonisation of wood-derived biochar that had been buried in an agricultural soil for three years. We have examined the level of colonisation on the internal and external surfaces of field-aged biochar by scanning electron microscopy, and used 14C-labelled glucose to quantify the rates of microbial activity in different spatial niches of the biochar and the surrounding soil. Microbial colonisation of field-aged biochar was very sparse, with no obvious differences between the external and internal surfaces. At the high field application rate of 50 t ha-1, biochar contributed only 6.52 ± 0.11% of the total soil pore space and 7.35 ± 0.81% of the total soil surface area of the topsoil (0-30 cm). Further, 17.46 ± 0.02% of the biochar pores were effectively uninhabitable for most microbes, being <1 μm in diameter. The initial rate of microbial mineralization of 14C-labelled glucose was significantly greater in the control bulk soil and the soil immediately surrounding the biochar than on the biochar external and internal surfaces. However, lower C use efficiency values of microbes on, or within, the biochar also suggested lower available C status or differences in the structure of the microbial community in the biochar relative to the surrounding soil. This study suggests that, at least in the short term (≤3 y), biochar does not provide a significant habitat for soil microbes. While biochar is extremely recalcitrant and largely unavailable to soil microbes, changes in soil physicochemical properties and the introduction of metabolically available labile compounds into the surrounding soil (the ‘charosphere') may significantly alter soil microbial activity and structure, which could ultimately affect soil-plant-microbe interactions. Therefore, before the wide-scale application of biochar to agricultural land is exploited, it is important that we understand further how the properties of biochar positively or negatively affect soil microbial communities, and in turn, how they interact with, and colonise biochar.
显示更多 [+] 显示较少 [-]Electrochemical and phylogenetic analyses of current-generating microorganisms in a thermophilic microbial fuel cell 全文
2013
Fu, Qian | Kobayashi, Hajime | Kawaguchi, Hideo | Vilcaez, Javier | Wakayama, Tatsuki | Maeda, Haruo | Sato, Kozo
To explore diversity of thermophilic exoelectrogens, a thermophilic microbial fuel cell was constructed. Population analysis of the anodic microorganisms suggested possible involvement of Caloramator-related bacteria in electricity generation. Pure culture of Caloramator australicus showed electricity-generating ability, indicating that the bacterium is a new thermophilic exoelectrogen.
显示更多 [+] 显示较少 [-]Mechanisms Regulating Mercury Bioavailability for Methylating Microorganisms in the Aquatic Environment: A Critical Review 全文
2013
Hsu-Kim, Heileen | Kucharzyk, Katarzyna H. | Zhang, Tong | Deshusses, Marc A.
Mercury is a potent neurotoxin for humans, particularly if the metal is in the form of methylmercury. Mercury is widely distributed in aquatic ecosystems as a result of anthropogenic activities and natural earth processes. A first step toward bioaccumulation of methylmercury in aquatic food webs is the methylation of inorganic forms of the metal, a process that is primarily mediated by anaerobic bacteria. In this Review, we evaluate the current state of knowledge regarding the mechanisms regulating microbial mercury methylation, including the speciation of mercury in environments where methylation occurs and the processes that control mercury bioavailability to these organisms. Methylmercury production rates are generally related to the presence and productivity of methylating bacteria and also the uptake of inorganic mercury to these microorganisms. Our understanding of the mechanisms behind methylation is limited due to fundamental questions related to the geochemical forms of mercury that persist in anoxic settings, the mode of uptake by methylating bacteria, and the biochemical pathway by which these microorganisms produce and degrade methylmercury. In anoxic sediments and water, the geochemical forms of mercury (and subsequent bioavailability) are largely governed by reactions between Hg(II), inorganic sulfides, and natural organic matter. These interactions result in a mixture of dissolved, nanoparticulate, and larger crystalline particles that cannot be adequately represented by conventional chemical equilibrium models for Hg bioavailability. We discuss recent advances in nanogeochemistry and environmental microbiology that can provide new tools and unique perspectives to help us solve the question of how microorganisms methylate mercury. An understanding of the factors that cause the production and degradation of methylmercury in the environment is ultimately needed to inform policy makers and develop long-term strategies for controlling mercury contamination.
显示更多 [+] 显示较少 [-]Total microbial biomass and metabolic state of microorganisms in a typical chernozem of Moldova 全文
2013
Frunze, N. I.
New data on the total microbial biomass and its metabolic state in a typical chernozem of Moldova were obtained. The carbon content of the microbial biomass in the arable chernozems varied from 419 to 1033 μg/g soil and from 1002 to 1432 μg C/g soil under the shelterbelts. The contents of the microbial biomass under the shelter belts was by 2.1–2.9, 1.6–2.2, and 1.2–1.3 times higher than that in the unfertilized and fertilized with mineral and organic nutrients chernozems, respectively. Crop rotations with and without lucerne were examined. The functional activity of the microbial communities in the chernozem was determined by their metabolic diversity, the ability to use alternative metabolic reactions, and the domination of r-strategists. The content of the active part of the microbial community in the natural ecosystems constituted approximately 1/3 (29.1% on the average) of the total microbial community; in the arable soils, it as lower (9.8–21.8%).
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