Porous Solid Media (Fractal Surfaces)

1993 ◽  
pp. 129-156
Author(s):  
K. S. Birdi
Keyword(s):  
Porous Solid ◽  
Fractal Surfaces ◽  
Solid Media

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

TEM processing procedure for a bacillus organism grown on solid media

1990 ◽  
Vol 48 (3) ◽  
pp. 624-625
Author(s):  
Jane Payne ◽  
Philip Coudron
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Fume Hood ◽  
Vacuum Aspiration ◽  
Solid Media ◽  
Transmission Electron ◽  
Solid Agar ◽  
Processing Procedure ◽  
Agar Media ◽  
Rat Bone

This transmission electron microscopy (TEM) procedure was designed to examine a gram positive spore-forming bacillus in colony on various solid agar media with minimal artifact. Cellular morphology and organization of colonies embedded in Poly/Bed 812 resin (P/B) were studied. It is a modification of procedures used for undecalcified rat bone and Stomatococcus mucilaginosus.Cultures were fixed and processed at room temperature (RT) under a fume hood. Solutions were added with a Pasteur pipet and removed by gentle vacuum aspiration. Other equipment used is shown in Figure 3. Cultures were fixed for 17-18 h in 10-20 ml of RT 2% phosphate buffered glutaraldehyde (422 mosm/KgH2O) within 5 m after removal from the incubator. After 3 (30 m) changes in 0.15 M phosphate buffer (PB = 209-213 mosm/KgH2O, pH 7.39-7.41), colony cut-outs (CCO) were made with a scalpel.

De novo metabolite production through co-cultivation of different fungal species on solid media

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
A Azzollini ◽  
JL Wolfender ◽  
K Gindro
Keyword(s):  
De Novo ◽  
Fungal Species ◽  
Metabolite Production ◽  
Solid Media

scholarly journals Mutations in fbiD (Rv2983) as a Novel Determinant of Resistance to Pretomanid and Delamanid in Mycobacterium tuberculosis

2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Evidence ◽  
Clinical Samples ◽  
Loss Of Function ◽  
Wild Type ◽  
Content Type ◽  
Solid Media ◽  
High Level ◽  
Level Resistance

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.

scholarly journals Copper Stress Targets the Rcs System To Induce Multiaggregative Behavior in a Copper-Sensitive Salmonella Strain

2010 ◽  
Vol 192 (23) ◽  
pp. 6287-6290 ◽  
Author(s):  
Lucas B. Pontel ◽  
Alejandro Pezza ◽  
Fernando C. Soncini
Keyword(s):  
Extracellular Polysaccharide ◽  
Copper Resistance ◽  
Copper Stress ◽  
Colanic Acid ◽  
Solid Media

ABSTRACT Salmonella ΔcuiD strains form mucoid colonies on copper-containing solid media. We show here that this multiaggregative behavior is caused by the Rcs-dependent induction of colanic acid extracellular polysaccharide. Deletion of cps operon genes in a ΔcuiD strain increased the sensitivity to copper, indicating a role for colanic acid in copper resistance.

scholarly journals Direct observations of shock-induced melting in a porous solid using time-resolved x-ray diffraction

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
A. Mandal ◽  
B. J. Jensen ◽  
M. C. Hudspeth ◽  
S. Root ◽  
R. S. Crum ◽  
...  
Keyword(s):  
Porous Solid ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Direct Observations
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