Lipopolysaccharide changes and cytoplasmic polyphosphate granule accumulation in Pseudomonas aeruginosa during growth on hexadecane

1986 ◽  
Vol 32 (3) ◽  
pp. 248-253 ◽  
Author(s):  
Carlos B. Miguez ◽  
Terry J. Beveridge ◽  
Jordan M. Ingram
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Sole Carbon Source ◽  
Cell Types ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Hydrophobicity Index ◽  
Active Growth ◽  
Thin Sections ◽  
X Ray ◽  
Lag Period

Pseudomonas aeruginosa ATCC 9027 grew on 0.5% (v/v) hexadecane as a sole carbon source in a chemically defined medium which required the addition of Fe3+ and Ca2+. There was a variable and extended lag period before an active growth rate was attained. Visible light microscopic evidence revealed that the bacteria did not adhere to hexadecane droplets suggesting the absence of a bioemulsifier. When compared with glucose-grown cells, hexadecane-grown cells produced 75% less lipopolysaccharide (on a total protein basis); this lipopolysaccharide contained 30–40% less carbohydrate, yet 50–75% more 2-keto-3-deoxyoctonate. These chemical changes made the cell surface appear more hydrophobic when tested in a biphasic hydrophobicity index system. Electron microscopy of thin sections and freeze etchings revealed hexadecane-grown cells contained granules which were judged to be polyphosphate by energy dispersive X-ray analysis. There was no apparent major morphological envelope alteration within the two cell types.

On the origin of variants of the marine bacteriumDeleya aesta134 able to grow at low Na+concentration

1997 ◽  
Vol 43 (9) ◽  
pp. 868-878 ◽  
Author(s):  
Robert A. MacLeod ◽  
Patricia R. MacLeod ◽  
Marc Berthelet
Keyword(s):  
Liquid Medium ◽  
Marine Bacteria ◽  
Lag Time ◽  
Defined Medium ◽  
Adaptive Mutation ◽  
Chemically Defined Medium ◽  
Colony Type ◽  
Lag Period ◽  
The Mean ◽  
Concentration Cells

Deleya aesta 134 grows optimally at 200 mM Na+in a chemically defined medium but at 10 mM Na+only after an extended lag period which was reduced if the cells that grew were reinoculated into medium of the same low Na+concentration. Cells that eventually grew at low Na+formed colonies on agar containing 17 mM Na+in the agar supernatant (the liquid released when the agar was compacted). Cells of the parent failed to form colonies at this Na+concentration when 102cells were plated. Colonies that formed on low Na+agar differed in appearance from colonies of the parent and three colony types were distinguished. When 106cells of D. aesta grown in liquid medium containing optimum Na+were spread on plates containing 17 mM Na+, a few variant colonies first appeared on day 4 and then increased in numbers over a 20-day period. In nine similar cultures the yield of colonies varied over a 3-log range. Fluctuation tests applied to the numbers arising from the similar cultures after different periods of incubation of the plates showed that the ratio of the variance to the mean was much greater than one initially and then increased with time. A total of seven different variants were isolated. These could be distinguished by the colony type formed, the length of the lag time preceding the first appearance of colonies, and the rate of colony accumulation on low (and in one case, high) Na+plates. The variants retained their distinctive characteristics when replated at low Na+after growth at optimum Na+. Differences in lag time and rate of colony accumulation were related to differences in Na+requirement of the variants and to the presence of other colonies on the plates. The variants appear to arise as the result of random mutations in the growing culture. There was no evidence of adaptive mutation.Key words: Deleya aesta, marine bacteria, variants, Na+response, colony accumulation, adaptive mutation.

Antigenic variation and increase in pathogenicity in Pseudomonas aeruginosa as a result of growth on glucose or N-hexadecane as sole carbon source

1978 ◽  
Vol 24 (6) ◽  
pp. 675-679 ◽  
Author(s):  
Robert S. Stinson ◽  
D. E. Talburt
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbon Source ◽  
Outer Membrane ◽  
Sole Carbon Source ◽  
Antigenic Variation ◽  
Protein Composition ◽  
Cell Types ◽  
Additional Protein

When Pseudomonas aeruginosa is grown on glucose as opposed to n-hexadecane as the sole carbon source, the antigenicity, virulence, and protein composition of the outer membrane are altered. The hydrocarbon-grown cells demonstrate a 3-log increase in virulence over the glucose-grown cells (in mice). There also appears to be an additional protein present in the outer membrane of the n-hexadecane-grown cells. This protein may contribute to the observed antigenic differences between the two cell types.

Selection of kidney cell types in primary glomerular explant outgrowths by in vitro culture conditions

1986 ◽  
Vol 84 (1) ◽  
pp. 69-92
Author(s):  
T.D. Oberley ◽  
A.H. Yang ◽  
J. Gould-Kostka
Keyword(s):  
Epithelial Cell ◽  
Cell Types ◽  
Defined Medium ◽  
Culture Conditions ◽  
Chemically Defined Medium ◽  
Cell Type ◽  
Epithelial Cell Type ◽  
Tubular Cells ◽  
Selection Of

Adult guinea pig glomeruli were grown in vitro either in serum or in a chemically defined medium. Glomeruli were plated either directly into plastic flasks or into plastic flasks that had been coated with the extracellular matrix produced by the PF-HR-9 mouse teratocarcinoma endodermal cell line. Both the composition of the medium and the nature of the culture substrate affected whole glomerular attachment and the type of cells produced in culture. Quantitative studies demonstrated selection of cell types by different culture conditions. Three colony types, each composed of distinctive cell types, could be identified by morphological features. The cells constituting two of these colony types were epithelial in nature, but they were identified as different epithelial types by both histochemical and ultrastructural criteria. Previous studies suggested that one epithelial cell type was derived from the glomerular visceral epithelial cell. This study demonstrates that this cell type could be selectively grown in defined medium on plastic. A second cell type showed several features of renal tubular epithelial cells, including histochemical staining for catalase, cell surface microvilli and cilia, and formation of hemicysts and structures that resembled tubules after prolonged periods in culture. To demonstrate that the ‘glomerulus-derived’ tubular cells were indeed tubular epithelium, we isolated purified renal cortical tubules (greater than 99% pure) and cultured them on the HR-9 matrix in a serum-free chemically defined medium. The resultant outgrowths had morphological properties identical to those of the glomerulus-derived tubular cells. It seems likely that small tubular fragments attached to a minority of the glomeruli are the source of these glomerulus-derived tubular cells. Neither epithelial cell type could be subcultured on plastic, but both could be passaged on the HR-9 matrix. A third cell type, the spindle-shaped cell, was easily propagated on both plastic and the HR-9 matrix. The origin of this cell type is not clear. Our results demonstrate the important effect of culture conditions on the selection, growth and differentiation of kidney cell types in vitro.

STEROL PRODUCTION BY SOME WOOD-ROTTING BASIDIOMYCETES

1965 ◽  
Vol 43 (11) ◽  
pp. 1347-1353 ◽  
Author(s):  
Francis H. Milazzo
Keyword(s):  
Growth Medium ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Active Growth

Fourteen species (six genera) of wood-rotting basidiomycetes cultured in a chemically defined medium were examined for the presence of sterol material. These fungi were found to contain ergosterol in amounts that ranged in value from 0.017 to 0.42% of their mycelial dry weights. Such values are, in general, comparable to sterol values reported for other fungi.The synthesis of sterol by Fomes meliae was found to accompany active growth of the fungus and was quantitatively influenced by the composition of the growth medium. Hexose supported greater production of sterol than did pentose, and organic nitrogen was superior to inorganic nitrogen in respect to this synthesis. The combination of hexose and organic nitrogen supported the greatest synthesis of sterol.

scholarly journals ‘Venus trapped, Mars transits': Cu and Fe redox chemistry, cellular topography and in situ ligand binding in terrestrial isopod hepatopancreas

Open Biology ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 150270
Author(s):  
P. Kille ◽  
A. J. Morgan ◽  
K. Powell ◽  
J. F. W. Mosselmans ◽  
D. Hart ◽  
...  
Keyword(s):  
B Cells ◽  
Bond Length ◽  
Cell Types ◽  
Thin Sections ◽  
X Ray ◽  
Nocturnal Feeding ◽  
Fe Speciation ◽  
Dietary Components ◽  
Morphological Relationship

Woodlice efficiently sequester copper (Cu) in ‘cuprosomes' within hepatopancreatic ‘S' cells. Binuclear ‘B’ cells in the hepatopancreas form iron (Fe) deposits; these cells apparently undergo an apocrine secretory diurnal cycle linked to nocturnal feeding. Synchrotron-based µ-focus X-ray spectroscopy undertaken on thin sections was used to characterize the ligands binding Cu and Fe in S and B cells of Oniscus asellus (Isopoda). Main findings were: (i) morphometry confirmed a diurnal B-cell apocrine cycle; (ii) X-ray fluorescence (XRF) mapping indicated that Cu was co-distributed with sulfur (mainly in S cells), and Fe was co-distributed with phosphate (mainly in B cells); (iii) XRF mapping revealed an intimate morphological relationship between the basal regions of adjacent S and B cells; (iv) molecular modelling and Fourier transform analyses indicated that Cu in the reduced Cu + state is mainly coordinated to thiol-rich ligands (Cu–S bond length 2.3 Å) in both cell types, while Fe in the oxidized Fe 3+ state is predominantly oxygen coordinated (estimated Fe–O bond length of approx. 2 Å), with an outer shell of Fe scatterers at approximately 3.05 Å; and (v) no significant differences occur in Cu or Fe speciation at key nodes in the apocrine cycle. Findings imply that S and B cells form integrated unit-pairs; a functional role for secretions from these cellular units in the digestion of recalcitrant dietary components is hypothesized.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

Chemical modification of the bacterial wall to determine sites of metal deposition

1978 ◽  
Vol 36 (2) ◽  
pp. 350-351
Author(s):  
T. J. Beveridge
Keyword(s):  
Electron Scattering ◽  
Metal Salt ◽  
Metal Deposition ◽  
Suitable Model ◽  
X Ray Diffraction ◽  
Subtilis Cell ◽  
Thin Sections ◽  
X Ray ◽  
Section Data ◽  
Metal Impregnation

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.

Biodegradation of chlorophenols by immobilized pure-culture microorganisms

1996 ◽  
Vol 34 (10) ◽  
pp. 67-72 ◽  
Author(s):  
Lu Chih-Jen ◽  
Lee Chi-Mei ◽  
Huang Chiou-Zong
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pseudomonas Putida ◽  
Pure Culture ◽  
The Other ◽  
Batch Reactors ◽  
Agrobacterium Radiobacter ◽  
Culture Cells ◽  
Lag Period

The biodegradation of phenol and chlorophenols by immobilized pure-culture cells was conducted by a series of batch reactors. The microorganisms used in this study were Pseudomonas putida, Psuedomonas testosteroni, Pseudomonas aeruginosa, and Agrobacterium radiobacter. All four species showed the ortho-cleavage pathway to metabolize chlorophenols. Among the four species, P. testosteroni, P. putida, and P. aeruginosa could effectively remove phenol at 200 mg/l. P. testosteroni could effectively remove 2-chlorophenol at 10mg/l. However, the other three species, P. putida, P. aeruginosa, and A. radiobacter, could not effectively remove 2-chlorophenol. Although 3-chlorophenol is a recalcitrant compound, P. testosteroni also could rapidly metabolize 3-chlorophenol at 10 mg/l. The removal of 4-chlorophenol at 10 mg/l by P. testosteroni reached 98% within one day. P. aeruginosa and A. radiobacter also could metabolize 4-chlorophenol after 2 and 7 days of lag period, respectively.

scholarly journals In situ differentiation of iridophore crystallotypes underlies zebrafish stripe patterning

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dvir Gur ◽  
Emily J. Bain ◽  
Kory R. Johnson ◽  
Andy J. Aman ◽  
H. Amalia Pasoili ◽  
...  
Keyword(s):  
Skin Color ◽  
Cell Types ◽  
Color Pattern ◽  
Single Type ◽  
Sequencing Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cryogenic Scanning Electron Microscopy ◽  
Different Cell Types

AbstractSkin color patterns are ubiquitous in nature, impact social behavior, predator avoidance, and protection from ultraviolet irradiation. A leading model system for vertebrate skin patterning is the zebrafish; its alternating blue stripes and yellow interstripes depend on light-reflecting cells called iridophores. It was suggested that the zebrafish’s color pattern arises from a single type of iridophore migrating differentially to stripes and interstripes. However, here we find that iridophores do not migrate between stripes and interstripes but instead differentiate and proliferate in-place, based on their micro-environment. RNA-sequencing analysis further reveals that stripe and interstripe iridophores have different transcriptomic states, while cryogenic-scanning-electron-microscopy and micro-X-ray diffraction identify different crystal-arrays architectures, indicating that stripe and interstripe iridophores are different cell types. Based on these results, we present an alternative model of skin patterning in zebrafish in which distinct iridophore crystallotypes containing specialized, physiologically responsive, organelles arise in stripe and interstripe by in-situ differentiation.

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