Microbial adaptation to iron: a possible role of phosphatidylethanolamine in iron mineral deposition

BioMetals ◽  
1995 ◽  
Vol 8 (2) ◽  
Author(s):  
V.D. Appanna ◽  
H. Finn
Keyword(s):  
Iron Mineral ◽  
Microbial Adaptation ◽  
Mineral Deposition

scholarly journals Role of Polyphosphates in Microbial Adaptation to Extreme Environments

2008 ◽  
Vol 74 (19) ◽  
pp. 5867-5874 ◽  
Author(s):  
Manfredo J. Seufferheld ◽  
H�ctor M. Alvarez ◽  
Maria E. Farias
Keyword(s):  
Extreme Environments ◽  
Microbial Adaptation

scholarly journals Marine Microbial Assemblages on Microplastics: Diversity, Adaptation, and Role in Degradation

2020 ◽  
Vol 12 (1) ◽  
pp. 209-232 ◽  
Author(s):  
Sonja Oberbeckmann ◽  
Matthias Labrenz
Keyword(s):  
Pathogenic Bacteria ◽  
Life Forms ◽  
Microbial Interactions ◽  
The Other ◽  
Human Society ◽  
Marine Microorganisms ◽  
Microbial Adaptation ◽  
Artificial Surfaces ◽  
Plastic Degradation

We have known for more than 45 years that microplastics in the ocean are carriers of microbially dominated assemblages. However, only recently has the role of microbial interactions with microplastics in marine ecosystems been investigated in detail. Research in this field has focused on three main areas: ( a) the establishment of plastic-specific biofilms (the so-called plastisphere); ( b) enrichment of pathogenic bacteria, particularly members of the genus Vibrio, coupled to a vector function of microplastics; and ( c) the microbial degradation of microplastics in the marine environment. Nevertheless, the relationships between marine microorganisms and microplastics remain unclear. In this review, we deduce from the current literature, new comparative analyses, and considerations of microbial adaptation concerning plastic degradation that interactions between microorganisms and microplastic particles should have rather limited effects on the ocean ecosystems. The majority of microorganisms growing on microplastics seem to belong to opportunistic colonists that do not distinguish between natural and artificial surfaces. Thus, microplastics do not pose a higher risk than natural particles to higher life forms by potentially harboring pathogenic bacteria. On the other hand, microplastics in the ocean represent recalcitrant substances for microorganisms that are insufficient to support prokaryotic metabolism and will probably not be microbially degraded in any period of time relevant to human society. Because we cannot remove microplastics from the ocean, proactive action regarding research on plastic alternatives and strategies to prevent plastic entering the environment should be taken promptly.

scholarly journals The effects of synthetic 19-norprogestins on osteoblastic cell function are mediated by their non-phenolic reduced metabolites

2007 ◽  
Vol 193 (3) ◽  
pp. 493-504 ◽  
Author(s):  
Juana Enríquez ◽  
Ana Elena Lemus ◽  
Jesús Chimal-Monroy ◽  
Higinio Arzate ◽  
Gustavo A García ◽  
...  
Keyword(s):  
Cell Function ◽  
Bone Cells ◽  
Neonatal Rat ◽  
Osteoblastic Cell ◽  
Osteoblast Proliferation ◽  
Mineral Deposition ◽  
Proliferation And Differentiation ◽  
Derivatives Of ◽  
Rat Osteoblasts

The key role of estrogens on osteoblastic cell function is well documented; however, the role of progesterone (P) and synthetic progestins remains controversial. While several reports indicate that P has no significant effects on bone cells, a number of clinical studies have shown that 19-norprogestins restore postmenopausal bone loss. The mechanisms by which 19-norprogestins induce estrogen-like effects on bone cells are not fully understood. To assess whether the actions of 19-norprogestins on osteoblasts are mediated by their non-phenolic metabolites, we studied the effects of norethisterone (NET), levonorgestrel (LNG), and two of their A-ring reduced derivatives upon cell proliferation and differentiation in neonatal rat osteoblasts. Osteoblast function was assessed by determining cell DNA, cell-associated osteocalcin and calcium content, alkaline phosphatase activity, and mineral deposition. P failed to induce changes on osteoblasts, while NET and LNG exerted a number of actions. The most striking finding was that the 3β,5α- and 3α,5α-tetrahydro derivatives of NET and LNG induced osteoblast proliferation and differentiation with higher potency than those exerted by their parent compounds, mimicking the effects of estradiol. Interestingly, osteoblast differentiation and mineral deposition induced by NET and LNG were abolished by finasteride, a 5α-reductases inhibitor, while the potent effect on osteoblast proliferation induced by progestin derivatives was abolished by a steroidal antiestrogen. Results demonstrate that A-ring reduced derivatives of NET and LNG exhibit intrinsic estrogen-like potency on rat osteoblasts, offering a plausible explanation for the mechanism of action of 19-norprogestins in bone restoration in postmenopausal women and providing new insights for hormone replacement therapy research.

scholarly journals Secondary Mineralization of Ferrihydrite Affects Microbial Methanogenesis in Geobacter-Methanosarcina Cocultures

2016 ◽  
Vol 82 (19) ◽  
pp. 5869-5877 ◽  
Author(s):  
Jia Tang ◽  
Li Zhuang ◽  
Jinlian Ma ◽  
Ziyang Tang ◽  
Zhen Yu ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Biogeochemical Cycling ◽  
Methanosarcina Barkeri ◽  
Geobacter Metallireducens ◽  
Methanogenic Activity ◽  
Content Type ◽  
Iron Minerals ◽  
Iron Mineral ◽  
Iron Mineralogy

ABSTRACTThe transformation of ferrihydrite to stable iron oxides over time has important consequences for biogeochemical cycling of many metals and nutrients. The response of methanogenic activity to the presence of iron oxides depends on the type of iron mineral, but the effects of changes in iron mineralogy on methanogenesis have not been characterized. To address these issues, we constructed methanogenic cocultures ofGeobacterandMethanosarcinastrains with different ferrihydrite mineralization pathways. In this system, secondary mineralization products from ferrihydrite are regulated by the presence or absence of phosphate. In cultures producing magnetite as the secondary mineralization product, the rates of methanogenesis from acetate and ethanol increased by 30.2% and 135.3%, respectively, compared with a control lacking ferrihydrite. Biogenic magnetite was proposed to promote direct interspecies electron transfer betweenGeobacterandMethanosarcinain a manner similar to that ofc-type cytochrome and thus facilitate methanogenesis. Vivianite biomineralization from ferrihydrite in the presence of phosphate did not significantly influence the methanogenesis processes. The correlation between magnetite occurrence and facilitated methanogenesis was supported by increased rates of methane production from acetate and ethanol with magnetite supplementation in the defined cocultures. Our data provide a new perspective on the important role of iron biomineralization in biogeochemical cycling of carbon in diverse anaerobic environments.IMPORTANCEIt has been found that microbial methanogenesis is affected by the presence of iron minerals, and their influences on methanogenesis are associated with the mineralogical properties of the iron minerals. However, how changes in iron mineralogy affect microbial methanogenesis has not been characterized. To address this issue, we constructed methanogenic cocultures ofGeobacterandMethanosarcinastrains with different ferrihydrite mineralization pathways. The experimental results led to two contributions, i.e., (i) the transformation of iron minerals might exert an important influence on methanogenesis under anaerobic conditions and (ii) both biogenic and chemical magnetite can accelerate syntrophic ethanol oxidization betweenGeobacter metallireducensandMethanosarcina barkeri. This study sheds new light on the important role of iron biomineralization in the biogeochemical cycling of carbon in diverse anaerobic environments, particularly in iron-rich natural and agricultural wetland soils.

scholarly journals Acidic monosaccharides become incorporated into calcite single crystals

2020 ◽  
Author(s):  
Arad Lang ◽  
Sylwia Mijowska ◽  
Iryna Polishchuk ◽  
Simona Fermani ◽  
Giuseppe Falini ◽  
...  
Keyword(s):  
Crystalline Lattice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Deposition ◽  
Anisotropic Lattice ◽  
Lattice Distortions ◽  
Shed Light ◽  
Proteins And Peptides

ABSTRACTCarbohydrates, along with proteins and peptides, are known to represent a major class of biomacromolecules involved in calcium carbonate biomineralization. However, in spite of multiple physical or biochemical characterizations, the explicit role of saccharide macromolecules (long chains of carbohydrate molecules) is not yet understood in mineral deposition. In the present study we investigated the influence of two common acidic monosaccharides (MSs), which are the simplest form of carbohydrates and are represented here by glucuronic and galacturonic acids, on the formation of calcite crystals in vitro. We show that the size, morphology and microstructure of calcite crystals are altered when they are grown in the presence of these MSs. More importantly, MSs were found to become incorporated into the calcite crystalline lattice and induce anisotropic lattice distortions, a widely studied phenomenon in other biomolecules related to CaCO3 biomineralization but never before reported in the case of single MSs. Changes in the calcite lattice induced by MS incorporation were precisely determined by the technique of high-resolution synchrotron powder X-ray diffraction. We believe that the results of this research may deepen our understanding of the interaction of saccharide polymers with an inorganic host and shed light on the implications of carbohydrates for biomineralization processes.

scholarly journals GIP: An open-source computational pipeline for mapping genomic instability from protists to cancer cells

2021 ◽  
Author(s):  
Gerald Frank Spaeth ◽  
Giovanni Bussotti
Keyword(s):  
Genome Instability ◽  
Microbial Populations ◽  
Single Nucleotide ◽  
Computational Tools ◽  
Genetic Changes ◽  
Bioinformatic Pipeline ◽  
Microbial Adaptation ◽  
Analytical Step ◽  
Key Driver

One of the hallmarks of eukaryotic pathogens is the ability to genetically adapt to environmental change, causing for instance frequent drug resistance. Even though genome instability has been recognized as a key driver for microbial adaptation, most available computational tools focus just on one mutation type or analytical step. To overcome this limitation and better understand the role of genetic changes in enhancing microbial pathogenicity we established GIP, a novel, powerful bioinformatic pipeline for comparative genome analysis across microbial populations. GIP allows batch processing of whole genome sequencing datasets, including read alignment, normalization, quantification of chromosomes, genes and genomic bins, and detection of single nucleotide and structural variants. GIP produces a comprehensive summary report providing sample statistics together with graphical representations of genomic features and tabulated results. GIP further includes a tool-suite that enables downstream custom comparisons of samples subsets. GIP is broadly applicable to different eukaryotic systems that exploit genome instability for adaptation, including Leishmania, Plasmodium, Candida, and cancer.

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