Participation des systèmes de captation des carbohydrates et de l'H+-ATPase de la membrane cytoplasmique lors de l'utilisation du glucose et du lactose par le Fusarium oxysporum var. lini

1988 ◽  
Vol 34 (8) ◽  
pp. 979-986 ◽  
Author(s):  
Rogelio Lopes Brandão ◽  
Jacques Robert Nicoli
Keyword(s):  
Carbon Source ◽  
Fusarium Oxysporum ◽  
Cytoplasmic Membrane ◽  
Growth Parameters ◽  
Fungal Growth ◽  
Transport Systems ◽  
Transport Mechanisms ◽  
Carbohydrate Transport ◽  
The Difference ◽  
Biphasic Profile

Growth parameters of Fusarium oxysporum var. lini in media containing glucose or lactose as carbon source were studied in relation to biochemical phenomenons such as transport mechanisms of each carbohydrate and the cytoplasmic membrane H+-ATPase activity. The following conclusions were reached. (i) The biphasic profile of the fungal growth on the medium containing glucose could be explained by the presence of two mechanisms of glucose uptake when an inoculum with derepressed carbohydrate transport systems was used. On the other hand, the existence of only one transport system for lactose in both repressed and derepressed cells could explain the monophasic growth curve on the medium containing this disaccharide. (ii) The difference in pH profiles observed during the growth of F. oxysporum var. lini on media containing glucose or lactose as carbon source could be explained by a differential activation of the cytoplasmic membrane H+-ATPase by the two carbohydrates.

scholarly journals The Effect of pH on Spore Germination, Growth, and Infection of Strawberry Roots by Fusarium oxysporum f. sp. fragariae, Cause of Fusarium wilt of Strawberry

Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 697-704 ◽  
Author(s):  
T. R. Gordon ◽  
M. Stueven ◽  
A. M. Pastrana ◽  
P. M. Henry ◽  
C. M. Dennehy ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Spore Germination ◽  
Fungal Growth ◽  
Root Infection ◽  
Effect Of Ph ◽  
Effects Of Ph ◽  
Strawberry Cultivar ◽  
The Difference ◽  
Hydrolysis Of

Previous work has shown that raising the pH of acidic soil to near neutrality can reduce the incidence of Fusarium wilt. The basis for this effect has not been established. The present study assessed effects of pH on spore germination, growth, and infection of strawberry roots by Fusarium oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry. There was not a significant effect of pH (5 versus 7) on the rate of spore germination at either 20 or 25°C for any of the three tested isolates (one representative of each clonal lineage of F. oxysporum f. sp. fragariae found in California). Likewise, pH did not have a significant effect on fungal growth at 20°C. At 25°C, two isolates grew faster at pH 7 than at pH 5. Growth of the third isolate was unaffected by the difference in pH. For the strawberry cultivar Albion, the frequency of root infection was significantly higher for plants grown in acidified soil (near pH 5) than for plants grown in soil near neutrality. The higher frequency of root infection in acidified soil was associated with a lower level of microbial activity, as measured by hydrolysis of fluorescein diacetate.

Transport Phenomena and Properties in Treelike Networks

2016 ◽  
Vol 68 (4) ◽  
Author(s):  
Peng Xu ◽  
Agus Pulung Sasmito ◽  
Boming Yu ◽  
Arun Sadashiv Mujumdar
Keyword(s):  
Transport Properties ◽  
Scaling Laws ◽  
Transport Phenomena ◽  
Transport Processes ◽  
Research Progress ◽  
Transport Systems ◽  
Transport Mechanisms ◽  
Branching Structures ◽  
Flow And Heat Transfer ◽  
Flow Heat

Treelike structures abound in natural as well as man-made transport systems, which have fascinated multidisciplinary researchers to study the transport phenomena and properties and understand the transport mechanisms of treelike structures for decades. The fluid flow and heat transfer in treelike networks have received an increasing attention over the past decade as the highly efficient transport processes observed in natural treelike structures can provide useful hints for optimal solutions to many engineering and industrial problems. This review paper attempts to present the background and research progress made in recent years on the transport phenomenon in treelike networks as well as technological applications of treelike structures. The subtopics included are optimization of branching structures, scaling laws of treelike networks, and transport properties for laminar flow, turbulent flow, heat conduction, and heat convection in treelike networks. Analytical expressions for the effective transport properties have been derived based on deterministic treelike networks, and the effect of branching parameters on the transport properties of treelike networks has also been discussed. Furthermore, numerical simulation results for treelike microchannel networks are presented as well. The proposed transport properties may be beneficial to understand the transport mechanisms of branching structures and promote the applications of treelike networks in engineering and industry.

scholarly journals Analysis of Predicted Carbohydrate Transport Systems Encoded by Bifidobacterium bifidum PRL2010

2012 ◽  
Vol 78 (14) ◽  
pp. 5002-5012 ◽  
Author(s):  
Francesca Turroni ◽  
Francesco Strati ◽  
Elena Foroni ◽  
Fausta Serafini ◽  
Sabrina Duranti ◽  
...  
Keyword(s):  
Bifidobacterium Bifidum ◽  
Transport Systems ◽  
Carbohydrate Utilization ◽  
Content Type ◽  
Carbohydrate Transport ◽  
Small Set ◽  
Transcriptome Analyses ◽  
Growth Experiments

ABSTRACTTheBifidobacterium bifidumPRL2010 genome encodes a relatively small set of predicted carbohydrate transporters. Growth experiments and transcriptome analyses ofB. bifidumPRL2010 revealed that carbohydrate utilization in this microorganism appears to be restricted to a relatively low number of carbohydrates.

scholarly journals Mycobacterium tuberculosis Is Able To Accumulate and Utilize Cholesterol

2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Cytoplasmic Membrane ◽  
Degradation Pathway ◽  
Cholesterol Accumulation ◽  
Targeted Disruption ◽  
Future Studies

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.

Ouabain, acetazolamide, and Cl-flux in isolated frog skin: evidence for two distinct active Cl-transport mechanisms

1977 ◽  
Vol 232 (6) ◽  
pp. F550-F558
Author(s):  
C. O. Watlington ◽  
S. D. Jessee ◽  
G. Baldwin
Keyword(s):  
Frog Skin ◽  
Rana Pipiens ◽  
The Other ◽  
Transport Systems ◽  
Transport Mechanisms ◽  
General Applicability ◽  
The Third ◽  
Cl Transport ◽  
Ouabain Sensitivity ◽  
Chloride Influx

Two distinctly different mechanisms for active Cl- transport in epithelia may exist: one, ouabain-sensitive and cation-dependent, and the other, acetazolamide-sensitive and cation-independent. As a test of this hypothesis the three active Cl- transport systems in isolated short-circuited skin of Rana pipiens were examined. Sensitivity to ouabain (10(-4) M) and acetazolamide (5 X 10(-3) M) and dependence on Na+ and K+ in the medium were ascertained. The first system, net chloride influx in ordinary Ringer, exhibited specific ouabain sensitivity and acetazolamide insensitivity. As we have previously shown this system to be clearly dependent on Na+ on the cis and K+ on the trans side, cation dependence was not re-studied. The second system, isoproterenol-stimulated net Cl- outflux, was also ouabain-sensitive and acetazolamide-insensitive. It was dependent on the presence of Na+ on the cis side, but the K+ dependence was less clear. In contrast to the first two, the third system (net influx in low Cl- medium sulfate Ringer containing 2.4 mM Cl-) was largely ouabain-insensitive, completely acetazolamide-sensitive and independent of both Na+ and K+. Thus, the hypothesis of two distinct mechanisms seems to hold for the three active Cl- transport systems in frog skin. Data from various other Cl- transporting epithelia are examined, and the general applicability of such a scheme of categorization for active Cl- transport mechanisms is discussed.

scholarly journals Relationship between newborn leptin levels and selected growth parameters

2019 ◽  
Vol 47 (6) ◽  
pp. 2591-2597 ◽  
Author(s):  
Amer Mahmoud Sindiani ◽  
Rawan Obeidat ◽  
Omar Jbarah ◽  
Ethar Hazaimeh
Keyword(s):  
Gestational Age ◽  
Head Circumference ◽  
Growth Parameters ◽  
Cross Sectional ◽  
Intrauterine Growth ◽  
The North ◽  
Term Newborns ◽  
The Mean ◽  
The Difference ◽  
Umbilical Cord Vein

Objectives This study aimed to determine leptin levels in term newborns who were born in the north of Jordan. We also aimed to investigate the relationships of leptin levels with fetal growth parameters, and to assess the difference in leptin levels according to sex and gestational age. Methods A cross-sectional descriptive study that involved 170 term newborns was conducted. A working sheet for data collection was created for each newborn and included sex, weight, length, head circumference, gestational age, and Apgar score. Blood samples were obtained from the umbilical cord vein of newborns after delivery to measure serum leptin levels. Data are shown as frequency, percentages, means, and standard deviations. Results We found that the mean leptin level was 1.17 ± 0.48 ng/mL. The independent t-test showed that the mean leptin level in boys (0.93 ± 0. 34 ng/mL) was significantly lower than that in girls (1.38 ± 0.47 ng/mL). Pearson’s correlations showed that leptin levels of newborns were positively and significantly correlated with weight, length, and head circumference. Conclusion In Jordanian healthy term newborns, leptin levels correlate with sex and intrauterine growth parameters.

scholarly journals Effects of Temperature and pH on Fusarium oxysporum and Soybean Seedling Disease

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3234-3243
Author(s):  
David R. Cruz ◽  
Leonor F. S. Leandro ◽  
Gary P. Munkvold
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Radial Growth ◽  
Culture Media ◽  
Fungal Growth ◽  
Artificial Culture ◽  
Vitro Assay ◽  
Seedling Disease ◽  
Soybean Seedlings

Fusarium oxysporum (Fo) is an important pathogen that reduces soybean yield by causing seedling disease and root rot. This study assessed the effects of pH and temperature on Fo fungal growth and seedling disease. In an in vitro assay, 14 Fo isolates collected from symptomatic soybean roots across Iowa in 2007 were grown on artificial culture media at five pH levels (4, 5, 6, 7, and 8) and incubated at four temperatures (15, 20, 25, or 30°C). In a rolled-towel assay, soybean seeds from Fo-susceptible cultivar Jack were inoculated with a suspension of a pathogenic or a nonpathogenic Fo isolate; both isolates were previously designated for their relative aggressiveness in causing root rot at 25°C. The seeds were placed in rolled germination paper, and the rolls were incubated in all combinations of buffer solutions at four pH levels (4, 5, 6, and 7), and four temperatures (15, 20, 25, or 30°C). There was a significant interaction between temperature and pH (P < 0.05) for in vitro radial growth and root rot severity. Isolates showed the most in vitro radial growth after incubation at pH 6 and 25°C. For the rolled-towel assay, the pathogenic isolate caused the most severe root rot at pH 6 and 30°C. Gaussian regression analysis estimates for optimal conditions were pH 6.3 at 27.1°C for maximal fungal growth and pH 5.9 at 30°C for maximal root rot severity. These results indicate that optimal pH and temperature conditions are similar for Fo growth and disease in soybean seedlings and suggest that Fo may be a more important seedling pathogen when soybeans are planted under warm conditions in moderately acidic soils.

Rat lung type II cell and lamellar body: elemental composition in situ

1988 ◽  
Vol 254 (5) ◽  
pp. C614-C620 ◽  
Author(s):  
R. G. Eckenhoff ◽  
A. P. Somlyo
Keyword(s):  
Elemental Composition ◽  
Lamellar Body ◽  
Cell Types ◽  
Transport Systems ◽  
Alveolar Type ◽  
Type Ii ◽  
Freeze Dried ◽  
Type Ii Cell ◽  
The Difference

We determined the in situ elemental composition of alveolar type II cells (ATII) and lamellar bodies (LB) with electronprobe microanalysis (EPMA) of freeze-dried unstained cryosections (100-200 nm) obtained from lungs frozen in anesthetized rats. Twenty-nine ATII from seven rats were subjected to EPMA. Cytoplasmic (Cyto) composition was the following (in mmol/kg dry wt, mean +/- SE, n = 30): 136 +/- 14.1 Na, 60 +/- 2.8 Mg, 549 +/- 34.8 P, 278 +/- 10.5 S, 158 +/- 7.3 Cl, 525 +/- 26.4 K, and 6.6 +/- 0.9 Ca. LB composition was the following (n = 66): 44 +/- 4.0 Na, 7.9 +/- 0.8 Mg, 1,060 +/- 25.0 P, 79 +/- 4.8 S, 64 +/- 3.6 Cl, 114 +/- 4.1 K, and 30 +/- 0.9 Ca. P and S concentrations were consistent with previous biochemical determinations of phospholipid and protein content of isolated LBs. LBs contain significantly more Ca and less Mg than Cyto. Ca correlated significantly with LB P but not S concentration, and the reported low Ca binding affinity of similar phospholipid mixtures implies a high LB free Ca concentration. Ca was significantly higher in apical and exocytotic LBs compared with those in the perinuclear region. Differences between LB and Cyto monovalent ion concentrations are not entirely due to the difference in hydration revealed by significantly lower K-Cl ratios in LBs. The relative excess of Cl and Ca in LB suggests that these ions may be distributed by active transport systems known to be present in the Golgi apparatus and in Golgi-derived organelles of other cell types.

Potential biological control of lesion nematodes on banana using Kenyan strains of endophytic Fusarium oxysporum

Nematology ◽  
2013 ◽  
Vol 15 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Bancy W. Waweru ◽  
Turoop Losenge ◽  
Esther M. Kahangi ◽  
Thomas Dubois ◽  
Daniel Coyne
Keyword(s):  
Fusarium Oxysporum ◽  
Growth Parameters ◽  
Positive Control ◽  
Lesion Nematodes ◽  
Root Necrosis ◽  
Significant Yield ◽  
Abiotic Constraints ◽  
Lesion Nematode ◽  
Growing Conditions ◽  
Pratylenchus Goodeyi

The root-lesion nematode Pratylenchus goodeyi is a common pest of banana in Kenya, which results in significant yield losses. An emerging option for the management of banana nematodes includes the use of endophytic fungi, which cause no damage to their hosts but often extend benefits, such as enhanced protection against various biotic and abiotic constraints. In the current study, non-pathogenic Fusarium oxysporum strains originating from banana (Musa spp.) in Kenya (4MOC321 and 11SR23) and Uganda (V5w2) were evaluated for their efficacy against P. goodeyi in tissue culture-derived plantlets (cv. Giant Cavendish and cv. Grand Nain) in pots. Pratylenchus goodeyi densities were 47-60% lower in endophyte-inoculated relative to non-inoculated plants and root necrosis damage was reduced by >30%. Endophyte treatment had no effect on plant growth parameters compared with untreated control plants. The performance of the two Kenyan strains was equally effective as the positive control (V5w2), thus demonstrating their potential as nematode bio-control agents under Kenyan growing conditions.

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