scholarly journals Genomic and Biochemical Studies Demonstrating the Absence of an Alkane-Producing Phenotype in Vibrio furnissii M1

2007 ◽  
Vol 73 (22) ◽  
pp. 7192-7198 ◽  
Author(s):  
Lawrence P. Wackett ◽  
Janice A. Frias ◽  
Jennifer L. Seffernick ◽  
David J. Sukovich ◽  
Stephan M. Cameron
Keyword(s):  
Genomic Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Rrna Gene ◽  
In Vivo Experiments ◽  
Cell Extracts ◽  
Highly Sensitive ◽  
Vibrio Furnissii ◽  
The 16S Rrna Gene

ABSTRACT Vibrio furnissii M1 was recently reported to biosynthesize n-alkanes when grown on biopolymers, sugars, or organic acids (M. O. Park, J. Bacteriol. 187:1426-1429, 2005). In the present study, V. furnissii M1 was subjected to genomic analysis and studied biochemically. The sequence of the 16S rRNA gene and repetitive PCR showed that V. furnissii M1 was not identical to other V. furnissii strains tested, but the level of relatedness was consistent with its assignment as a V. furnissii strain. Pulsed-field gel electrophoresis showed chromosomal bands at approximately 3.2 and 1.8 Mb, similar to other Vibrio strains. Complete genomic DNA from V. furnissii M1 was sequenced with 21-fold coverage. Alkane biosynthetic and degradation genes could not be identified. Moreover, V. furnissii M1 did not produce demonstrable levels of n-alkanes in vivo or in vitro. In vivo experiments were conducted by growing V. furnissii M1 under different conditions, extracting with solvent, and analyzing extracts by gas chromatography-mass spectrometry. A highly sensitive assay was used for in vitro experiments with cell extracts and [14C]hexadecanol. The data are consistent with the present strain being a V. furnissii with properties similar to those previously described but lacking the alkane-producing phenotype. V. furnissii ATCC 35016, also reported to biosynthesize alkanes, was found in the present study not to produce alkanes.

scholarly journals A complex control region of the mouse rRNA gene directs accurate initiation by RNA polymerase I.

1985 ◽  
Vol 5 (3) ◽  
pp. 554-562 ◽  
Author(s):  
K G Miller ◽  
J Tower ◽  
B Sollner-Webb
Keyword(s):  
Initiation Site ◽  
Rrna Gene ◽  
Sufficient Information ◽  
Reaction Conditions ◽  
Cell Extracts ◽  
S 100 ◽  
Initiation Reaction ◽  
Polymerase I

To determine the size and location of the mouse rDNA promoter, we constructed systematic series of deletion mutants approaching the initiation site from the 5' and 3' directions. These templates were transcribed in vitro under various conditions with S-100 and whole-cell extracts. Surprisingly, the size of the rDNA region that determines the level of transcription differed markedly, depending on the reaction conditions. In both kinds of cell extracts, the apparent 5' border of the promoter was at residue ca. -27 under optimal transcription conditions, but as reaction conditions became less favorable, the 5' border moved progressively out to residues -35, -39, and -45. The complete promoter, however, extends considerably further, for under other nonoptimal conditions, we observed major effects of promoter domains extending in the 5' direction to positions ca. -100 and -140. In contrast, the apparent 3' border of the mouse rDNA promoter was at residue ca. +9 under all conditions examined. We also show that the subcloned rDNA region from -39 to +9 contains sufficient information to initiate accurately and that the region between +2 and +9 can influence the specificity of initiation. These data indicate that, although the polymerase I transcription factors recognize and accurately initiate with only the sequences downstream of residue -40, sequences extending out to residue -140 greatly favor the initiation reaction; presumably, this entire region is involved in rRNA transcription in vivo.

scholarly journals In vitro evaluation of lactic acid bacteria with probiotic activity isolated from local pickled leaf mustard from Wuwei in Anhui as substitutes for chemical synthetic additives

2021 ◽  
Vol 19 (1) ◽  
pp. 755-771
Author(s):  
Changjun Wu ◽  
Xiaopei Lin ◽  
Lin Tong ◽  
Chenwei Dai ◽  
Han Lv ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Animal Experiments ◽  
Rrna Gene ◽  
Intestinal Microbes ◽  
Potential Resource ◽  
The 16S Rrna Gene ◽  
Ht 29

Abstract The extensive abuse of chemical synthetic additives has raised increased attention to food safety. As substitutes, probiotics play an important role in human health as they balance the intestinal microbes in host. This study was aimed to isolate and evaluate the potential probiotic activities of lactic acid bacteria (LAB) from a local pickled leaf mustard (PLM) from Wuwei city in Anhui province through in vitro experiments. A total of 17 LAB strains were obtained as probiotics. All the isolates were sensitive to chloramphenicol, tetracycline, erythromycin, and doxycycline but exhibited resistance to antibiotics (e.g., streptomycin, kanamycin, gentamicin, and vancomycin). Out of the 17 strains, 9 were sensitive to most of the antibiotics and had no cytotoxic activity on human colorectal adenocarcinoma cell line (HT-29) cells. The isolated AWP4 exhibited antibacterial activity against four indicator pathogen strains (ATCC8099: Escherichia coli, ATCC6538: Staphylococcus aureus, ATCC9120: Salmonella enteric, and BNCC192105: Shigella sonnei). Based on the phylogenetic analysis of the 16S rRNA gene, AWP4 belonged to Lactiplantibacillus plantarum. This study indicated that the Wuwei local PLM could be a potential resource to isolate beneficial LAB as probiotics. The data provide theoretical guidance for further animal experiments to estimate the probiotic effect and safety of Lpb. plantarum AWP4 in vivo.

scholarly journals Phasic oxygen dynamics confounds fast choline-sensitive biosensor signals in the brain of behaving rodents

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ricardo M Santos ◽  
Anton Sirota
Keyword(s):  
Field Potential ◽  
Choline Oxidase ◽  
Fast Time ◽  
In Vivo Experiments ◽  
Highly Sensitive ◽  
Cortical Physiology ◽  
Oxygen Dynamics ◽  
The Brain

Cholinergic fast time-scale modulation of cortical physiology is critical for cognition, but direct local measurement of neuromodulators in vivo is challenging. Choline oxidase (ChOx)-based electrochemical biosensors have been used to capture fast cholinergic signals in behaving animals. However, these transients might be biased by local field potential and O2-evoked enzymatic responses. Using a novel Tetrode-based Amperometric ChOx (TACO) sensor, we performed highly sensitive and selective simultaneous measurement of ChOx activity (COA) and O2. In vitro and in vivo experiments, supported by mathematical modeling, revealed that non-steady-state enzyme responses to O2 give rise to phasic COA dynamics. This mechanism accounts for most of COA transients in the hippocampus, including those following locomotion bouts and sharp-wave/ripples. Our results suggest that it is unfeasible to probe phasic cholinergic signals under most behavioral paradigms with current ChOx biosensors. This confound is generalizable to any oxidase-based biosensor, entailing rigorous controls and new biosensor designs.

A complex control region of the mouse rRNA gene directs accurate initiation by RNA polymerase I

1985 ◽  
Vol 5 (3) ◽  
pp. 554-562
Author(s):  
K G Miller ◽  
J Tower ◽  
B Sollner-Webb
Keyword(s):  
Initiation Site ◽  
Rrna Gene ◽  
Sufficient Information ◽  
Reaction Conditions ◽  
Cell Extracts ◽  
S 100 ◽  
Initiation Reaction ◽  
Polymerase I

To determine the size and location of the mouse rDNA promoter, we constructed systematic series of deletion mutants approaching the initiation site from the 5' and 3' directions. These templates were transcribed in vitro under various conditions with S-100 and whole-cell extracts. Surprisingly, the size of the rDNA region that determines the level of transcription differed markedly, depending on the reaction conditions. In both kinds of cell extracts, the apparent 5' border of the promoter was at residue ca. -27 under optimal transcription conditions, but as reaction conditions became less favorable, the 5' border moved progressively out to residues -35, -39, and -45. The complete promoter, however, extends considerably further, for under other nonoptimal conditions, we observed major effects of promoter domains extending in the 5' direction to positions ca. -100 and -140. In contrast, the apparent 3' border of the mouse rDNA promoter was at residue ca. +9 under all conditions examined. We also show that the subcloned rDNA region from -39 to +9 contains sufficient information to initiate accurately and that the region between +2 and +9 can influence the specificity of initiation. These data indicate that, although the polymerase I transcription factors recognize and accurately initiate with only the sequences downstream of residue -40, sequences extending out to residue -140 greatly favor the initiation reaction; presumably, this entire region is involved in rRNA transcription in vivo.

scholarly journals Evaluation of the Effect of a Grape Seed Tannin Extract on Wine Ester Release and Perception Using In Vitro and In Vivo Instrumental and Sensory Approaches

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 93
Author(s):  
Carolina Muñoz-González ◽  
Celia Criado ◽  
María Pérez-Jiménez ◽  
María Ángeles Pozo-Bayón
Keyword(s):  
Grape Seed ◽  
Stir Bar Sorptive Extraction ◽  
Gas Chromatography Mass Spectrometry ◽  
Dependent Manner ◽  
Tannin Extract ◽  
Ethyl Hexanoate ◽  
In Vivo Experiments ◽  
Ethyl Decanoate

This study aimed to systematically evaluate the effect of a commercial grape seed tannin extract (GSE) fully characterized (53% monomers, 47% procyanidins) on wine ester release and perception using a global approach. The behavior of two esters (ethyl hexanoate, ethyl decanoate) was studied in a control wine or in the same wine supplemented with the GSE in preconsumption (in vitro headspace-stir bar sorptive extraction-gas chromatography mass spectrometry (HS-SBSE-GC/MS) and orthonasal perception) and consumption (intraoral-HS-SBSE-GC/MS and dynamic retronasal perception) conditions. For the compound ethyl hexanoate, no significant differences (p > 0.05) among wines were observed in the in vitro analyses while they were observed in the three in vivo experiments (p < 0.05). Thus, the wine supplemented with the GSE showed lower (35%) in vivo release and ortho (36%) and retronasal (16%) perception scores than the control wine. Overall, this suggests that components of the GSE could interact with this compound, directly and/or through complexes with oral components, affecting its release and conditioning its perception. However, perceptual interactions and effects of polyphenols on oral esterases cannot be discarded. On the contrary, the compound ethyl decanoate was not significantly affected by the addition of GSE. In conclusion, the addition of tannin extracts to wines can modulate aroma perception in a compound-dependent manner.

Identification of 16S rRNA mutations in Mycoplasma genitalium potentially associated with tetracycline resistance in vivo but not selected in vitro in M. genitalium and Chlamydia trachomatis

2021 ◽  
Author(s):  
Chloé Le Roy ◽  
Arabella Touati ◽  
Carla Balcon ◽  
Justine Garraud ◽  
Jean-Michel Molina ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Tetracycline Resistance ◽  
Mycoplasma Genitalium ◽  
Rrna Gene ◽  
Resistant Mutants ◽  
The 16S Rrna Gene

Abstract Objectives Tetracyclines are widely used for the treatment of bacterial sexually transmitted infections (STIs) and recently have been used successfully for post-exposure prophylaxis of STIs in MSM. We investigated the in vitro and in vivo development of tetracycline resistance in Chlamydia trachomatis and Mycoplasma genitalium and evaluated 16S rRNA mutations associated with acquired resistance in other bacteria. Methods In vitro selection of resistant mutants of reference strains of C. trachomatis and M. genitalium was undertaken by serial passage in medium containing subinhibitory concentrations of tetracycline or doxycycline, respectively. The 16S rRNA gene of the two microorganisms was amplified and sequenced at different passages, as were those of 43 C. trachomatis- and 106 M. genitalium-positive specimens collected in France from 2013 to 2019. Results No tetracycline- or doxycycline-resistant strains of C. trachomatis and M. genitalium, respectively, were obtained after 30 serial passages. The tetracycline and doxycycline MICs were unchanged and analysis of the 16S rRNA gene, the molecular target of tetracyclines, of C. trachomatis and M. genitalium revealed no mutation. No mutation in the 16S rRNA gene was detected in C. trachomatis-positive specimens. However, six M. genitalium-positive specimens harboured a mutation potentially associated with tetracycline resistance without known prior tetracycline treatment for patients. Conclusions Tetracyclines did not select in vitro-resistant mutants of C. trachomatis or M. genitalium. However, 16S rRNA mutations either responsible for or associated with tetracycline resistance in other bacteria, including mycoplasma species, were identified in several M. genitalium-positive specimens.

ANTITUMOR EFFECT OF COLLOIDAL SILVER BISILICATE IN EXPERIMENTAL IN VITRO AND IN VIVO STUDIES

2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Human Tumor ◽  
Significant Inhibition ◽  
In Vivo Studies ◽  
Ehrlich Carcinoma ◽  
In Vivo Experiments

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.

scholarly journals Plant-Derived Extracellular Vesicles: Current Findings,Challenges, and Future Applications

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 411
Author(s):  
Nader Kameli ◽  
Anya Dragojlovic-Kerkache ◽  
Paul Savelkoul ◽  
Frank R. Stassen
Keyword(s):  
Human Health ◽  
Extracellular Vesicles ◽  
Preliminary Results ◽  
In Vivo Experiments ◽  
Health And Disease ◽  
Conducting Research ◽  
Protocol Standardization ◽  
Insight Into

In recent years, plant-derived extracellular vesicles (PDEVs) have gained the interest of many experts in fields such as microbiology and immunology, and research in this field has exponentially increased. These nano-sized particles have provided researchers with a number of interesting findings, making their application in human health and disease very promising. Both in vitro and in vivo experiments have shown that PDEVs can exhibit a multitude of effects, suggesting that these vesicles may have many potential future applications, including therapeutics and nano-delivery of compounds. While the preliminary results are promising, there are still some challenges to face, such as a lack of protocol standardization, as well as knowledge gaps that need to be filled. This review aims to discuss various aspects of PDEV knowledge, including their preliminary findings, challenges, and future uses, giving insight into the complexity of conducting research in this field.

scholarly journals Osteoprotective Effects of Loganic Acid on Osteoblastic and Osteoclastic Cells and Osteoporosis-Induced Mice

2020 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
Eunkuk Park ◽  
Chang Gun Lee ◽  
Eunguk Lim ◽  
Seokjin Hwang ◽  
Seung Hee Yun ◽  
...  
Keyword(s):  
Osteoclast Differentiation ◽  
Osteoblastic Differentiation ◽  
Common Disease ◽  
Root Extract ◽  
Mouse Bone Marrow ◽  
Mineral Density ◽  
Bone Mineral Density Loss ◽  
In Vivo Experiments

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.

Sign in / Sign up

Export Citation Format

Share Document