The complex role of microbial metabolic activity in fossilization

ABSTRACT The uteri of pseudopregnant rats show a peak of metabolic activity on the 4th and 5th day of leucocytic smear. After the administration of 20 mg of pyrathiazine Cl on the 4th day of pseudopregnancy (L4) in order to induce decidualization of the progestational endometrium, the metabolic activity of the uterus becomes intensified. The amount of synthesis, estimated by determinations of uterine weight, and amount of protein and nucleic acids, was considered as being related to an oestrogen surge occurring on the 3rd day. The present work was undertaken to confirm the relation between the oestrogen surge and the metabolic activity found in the uterus thereafter by using an antioestrogenic substance: ethanoxytriphetol (MER-25). The experiments were performed in pseudopregnant as well as in decidualizing animals. MER-25 was injected on the 3rd day of leucocytic vaginal smear of pseudopregnancy. Analyses of the uterine components 24, 48, 72, 96 h after the injection of the antioestrogen showed a definite inhibition of the synthetic processes in the uterus of the otherwise untreated pseudopregnant rat as well as in decidualizing uterus. The results, confirm the role of oestrogen surge in the processes of decidualization and the close relationship between the oestrogen surge, increase of metabolism and decidualization.

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Earthworm communities and microbial metabolic activity and diversity under conventional, feed and biogas cropping systems as affected by tillage practices

Applied Soil Ecology ◽

10.1016/j.apsoil.2021.104232 ◽

2022 ◽

Vol 169 ◽

pp. 104232

Author(s):

Julia Denier ◽

Michel-Pierre Faucon ◽

Anne-Maïmiti Dulaurent ◽

Julien Guidet ◽

Léa Kervroëdan ◽

...

Keyword(s):

Metabolic Activity ◽

Cropping Systems ◽

Tillage Practices ◽

Microbial Metabolic Activity

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Metabolic activity of gut microbiota and xenobiotics

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn1528047b ◽

2015 ◽

pp. 47-55 ◽

Cited By ~ 2

Author(s):

Gordana Bojic ◽

Svetlana Golocorbin-Kohn ◽

Maja Stojancevic ◽

Momir Mikov ◽

Ljiljana Suvajdzic

Keyword(s):

Gut Microbiota ◽

Human Health ◽

Metabolic Activity ◽

Bacterial Population ◽

Great Benefit ◽

Host Organism ◽

Symbiotic Microorganisms ◽

Metabolic Activities ◽

Bacterial Genes

The intestine habitat is the natural collection of symbiotic microorganisms. The bacterial population enables many permanent metabolic activities in this environment. Inside the intestine of mammals there are an extended genome of millions of bacterial genes named microbiome. In recent years, there has been an increased interest of scientists to discover the place and the role of bio-ecological content and modulation of gut microbiota in a host organism using prebiotics, probiotics and synbiotics, which may have a great benefit for human health.

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The role of the cytoskeleton in mechanotransduction in human osteoblastlike cells

Human & Experimental Toxicology ◽

10.1191/0960327103ht362oa ◽

2003 ◽

Vol 22 (5) ◽

pp. 271-274 ◽

Cited By ~ 23

Author(s):

Nahum Rosenberg

Keyword(s):

Metabolic Activity ◽

Mechanical Stimulation ◽

Dna Content ◽

Cellular Mechanisms ◽

Unique Role ◽

Key Factor ◽

Total Dna ◽

Static Conditions ◽

Expected Increase

The regulation of osteoblast proliferation is a key factor in maintaining bone mass. The enhancement of this process can be achieved by stimulating the proliferation of these cells. Mechanical stimulation is one of the important enhancing factors, but the exact cellular mechanisms of mechanical stimulation, i.e., mechanotransduction, are unknown. In order to investigate the role of the cytoskeleton components in mechanotransduction for cell proliferation, I compared the total DNA content in cultured replicates of osteoblast-like cells derived from three human donors following their exposure to enhancing mechanical stimulation, with and without added specific microtubular and microfilament polymerization blockers (Colchicin and Cytochalasin D, respectively). The results revealed the essential and unique role of the microtubular component of the cytoskeleton in mechanotransduction for proliferation by showing that Colchicin blocked the expected increase in the DNA content after mechanical stimulation of the cultured replicates without altering the total DNA content in replicates at static conditions. Conversely, a specific blockage of the microfilament polymerization presented uniform cytotoxic effect in both static and biomechanically active environments. Since previous reports indicated the essential role of microfilament polymerization for the osteoblast metabolic activity, the results of this study further support the hypothesis that the mechanotransduction mechanisms for proliferation and metabolic activity are mediated by different intracellular pathways.

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Metabolic Current Production by an Oral Biofilm Pathogen Corynebacterium matruchotii

Molecules ◽

10.3390/molecules25143141 ◽

2020 ◽

Vol 25 (14) ◽

pp. 3141

Author(s):

Divya Naradasu ◽

Waheed Miran ◽

Akihiro Okamoto

Keyword(s):

Metabolic Activity ◽

High Resolution Mass Spectrometry ◽

Electrode System ◽

Human Pathogens ◽

Oral Biofilm ◽

Hydrogen Electrode ◽

Production Capability ◽

Current Production ◽

The Impact ◽

Microbial Metabolic Activity

The development of a simple and direct assay for quantifying microbial metabolic activity is important for identifying antibiotic drugs. Current production capabilities of environmental bacteria via the process called extracellular electron transport (EET) from the cell interior to the exterior is well investigated in mineral-reducing bacteria and have been used for various energy and environmental applications. Recently, the capability of human pathogens for producing current has been identified in different human niches, which was suggested to be applicable for drug assessment, because the current production of a few strains correlated with metabolic activity. Herein, we report another strain, a highly abundant pathogen in human oral polymicrobial biofilm, Corynebacterium matruchotii, to have the current production capability associated with its metabolic activity. It showed the current production of 50 nA/cm2 at OD600 of 0.1 with the working electrode poised at +0.4 V vs. a standard hydrogen electrode in a three-electrode system. The addition of antibiotics that suppress the microbial metabolic activity showed a significant current decrease (>90%), establishing that current production reflected the cellular activity in this pathogen. Further, the metabolic fixation of atomically labeled 13C (31.68% ± 2.26%) and 15N (19.69% ± 1.41%) confirmed by high-resolution mass spectrometry indicated that C. matruchotii cells were metabolically active on the electrode surface. The identified electrochemical activity of C. matruchotii shows that this can be a simple and effective test for evaluating the impact of antibacterial compounds, and such a method might be applicable to the polymicrobial oral biofilm on electrode surfaces, given four other oral pathogens have already been shown the current production capability.

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Visualization is crucial for understanding microbial processes in the ocean

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0083 ◽

2019 ◽

Vol 374 (1786) ◽

pp. 20190083 ◽

Cited By ~ 5

Author(s):

Marta Sebastián ◽

Josep M. Gasol

Keyword(s):

Single Cell ◽

Metabolic Activity ◽

Cell Activity ◽

Level Of Activity ◽

Single Cell Activity ◽

Recent Developments ◽

Insight Into ◽

Do So

Recent developments in community and single-cell genomic approaches have provided an unprecedented amount of information on the ecology of microbes in the aquatic environment. However, linkages between each specific microbe's identity and their in situ level of activity (be it growth, division or just metabolic activity) are much more scarce. The ultimate goal of marine microbial ecology is to understand how the environment determines the types of different microbes in nature, their function, morphology and cell-to-cell interactions and to do so we should gather three levels of information, the genomic (including identity), the functional (activity or growth), and the morphological, and for as many individual cells as possible. We present a brief overview of methodologies applied to address single-cell activity in marine prokaryotes, together with a discussion of the difficulties in identifying and categorizing activity and growth. We then provide and discuss some examples showing how visualization has been pivotal for challenging established paradigms and for understanding the role of microbes in the environment, unveiling processes and interactions that otherwise would have been overlooked. We conclude by stating that more effort should be directed towards integrating visualization in future approaches if we want to gain a comprehensive insight into how microbes contribute to the functioning of ecosystems. This article is part of a discussion meeting issue ‘Single cell ecology’.

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