The separation of alginate biosynthesis and acetylation in Pseudomonas syringae

1998 ◽  
Vol 44 (4) ◽  
pp. 394-398 ◽  
Author(s):  
Jin W Lee ◽  
F Day
Keyword(s):  
Pseudomonas Syringae ◽  
Culture Medium ◽  
Enzyme System ◽  
Indirect Evidence ◽  
Resting Cells ◽  
Resting Cell ◽  
Degree Of Acetylation ◽  
Induced Mutants ◽  
Alginate Acetylation ◽  
Alginate Biosynthesis

Seaweed alginate was acetylated by resting cells of Pseudomonas syringae subsp. phaseolicola ATCC 19304. Physiological studies on this strain and its UV-induced mutants showed no correlation between bacterial alginate biosynthesis and acetylation. Specific yields of alginate and degree of acetylation in these polymers varied with strain and culture medium. This was indirect evidence that alginate biosynthesis is separate from polysaccharide acetylation. It indicated that the enzyme system involved in alginate biosynthesis was not directly linked to alginate acetylation and explained why microbial acetylation of seaweed alginates was possible.Key words: resting cell, Pseudomonas syringae, acetylation, bacterial alginate, seaweed alginate.

Ultrastructure of Melosira resting cell rejuvenation

1984 ◽  
Vol 42 ◽  
pp. 734-735
Author(s):  
C. E. M. Bourne ◽  
L. Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Lake Michigan ◽  
Light And Electron Microscopy ◽  
Resting Cells ◽  
Planktonic Diatoms ◽  
Resting Cell ◽  
Vegetative Survival ◽  
Cytological Changes ◽  
Recent Attention ◽  
Freshwater Diatom

Much recent attention has been focused on vegetative survival forms of planktonic diatoms and other algae. There are several reports of extended vegetative survival of the freshwater diatom Melosira in lake sediments. In contrast to those diatoms which form a morphologically distinct resistant spore, Melosira is known to produce physiological resting cells that are indistinguishable in outward morphology from actively growing cells.We used both light and electron microscopy to document and elucidate the sequence of cytological changes during the transition from resting cells to actively growing cells in a population of Melosira granulata from Douglas Lake, Michigan sediments collected in mid-July of 1983.

scholarly journals The algT Gene of Pseudomonas syringae pv. glycinea andNew Insights into the Transcriptional Organization of thealgT-muc Gene Cluster

2006 ◽  
Vol 188 (23) ◽  
pp. 8013-8021 ◽  
Author(s):  
Alexander Schenk ◽  
Michael Berger ◽  
Lisa M. Keith ◽  
Carol L. Bender ◽  
Georgi Muskhelishvili ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Azotobacter Vinelandii ◽  
Regulatory Gene ◽  
In Planta ◽  
Phytopathogenic Bacterium ◽  
Reverse Transcription Pcr ◽  
Alginate Production ◽  
Alginate Biosynthesis

ABSTRACT The phytopathogenic bacterium Pseudomonas syringae pv. glycinea infects soybean plants and causes bacterial blight. In addition to P. syringae, the human pathogen Pseudomonas aeruginosa and the soil bacterium Azotobacter vinelandii produce the exopolysaccharide alginate, a copolymer of d-mannuronic and l-guluronic acids. Alginate production in P. syringae has been associated with increased fitness and virulence in planta. Alginate biosynthesis is tightly controlled by proteins encoded by the algT-muc regulatory gene cluster in P. aeruginosa and A. vinelandii. These genes encode the alternative sigma factor AlgT (σ22), its anti-sigma factors MucA and MucB, MucC, a protein with a controversial function that is absent in P. syringae, and MucD, a periplasmic serine protease and homolog of HtrA in Escherichia coli. We compared an alginate-deficient algT mutant of P. syringae pv. glycinea with an alginate-producing derivative in which algT is intact. The alginate-producing derivative grew significantly slower in vitro growth but showed increased epiphytic fitness and better symptom development in planta. Evaluation of expression levels for algT, mucA, mucB, mucD, and algD, which encodes an alginate biosynthesis gene, showed that mucD transcription is not dependent on AlgT in P. syringae in vitro. Promoter mapping using primer extension experiments confirmed this finding. Results of reverse transcription-PCR demonstrated that algT, mucA, and mucB are cotranscribed as an operon in P. syringae. Northern blot analysis revealed that mucD was expressed as a 1.75-kb monocistronic mRNA in P. syringae.

Effect of culture medium ions on chromate reduction by resting cells of Agrobacterium radiobacter

1993 ◽  
Vol 39 (3) ◽  
Author(s):  
Santiago LLovera ◽  
Ramon Bonet ◽  
MariaDolores Simon-Pujol ◽  
Francisco Congregado
Keyword(s):  
Culture Medium ◽  
Chromate Reduction ◽  
Resting Cells ◽  
Agrobacterium Radiobacter

The metabolism of p-fluorophenylacetic acid by a Pseudomonas sp. I. Isolation and identification of intermediates in degradation

1971 ◽  
Vol 17 (5) ◽  
pp. 635-644 ◽  
Author(s):  
D. B. Harper ◽  
E. R. Blakley
Keyword(s):  
Sole Carbon Source ◽  
Culture Medium ◽  
Enrichment Culture ◽  
Culture Technique ◽  
Spectroscopic Techniques ◽  
Resting Cells ◽  
Pseudomonas Sp ◽  
Isolation And Identification ◽  
Hydroxyphenylacetic Acid ◽  
Organic Fluorine

A Pseudomonas sp. capable of growing on p-fluorophenylacetic acid as sole carbon source has been isolated using the enrichment culture technique. All the organic fluorine is released into the culture medium as fluoride ion during growth. A number of fluorinated intermediates have been isolated from the culture medium when resting cells were incubated with the substrate. Using infrared, nuclear magnetic resonance, and mass spectroscopic techniques together with chemical degradative procedures, these have been identified as D(+)-monofluorosuccinic acid, trans-3-fluoro-3-hexenedioic acid, (−)-4-carboxymethyl-4-fluorobutanolide, 4-fluoro-2-hydroxyphenylacetic acid, and 4-fluoro-3-hydroxyphenylacetic acid.

Detection Method for Histamine-Producing, Dairy-Related Bacteria using Diamine Oxidase and Leucocrystal Violet

1989 ◽  
Vol 52 (2) ◽  
pp. 105-108 ◽  
Author(s):  
SUSAN S. SUMNER ◽  
STEVE L. TAYLOR
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Culture ◽  
Diamine Oxidase ◽  
Culture Medium ◽  
Detection Method ◽  
Enzyme System ◽  
Color Formation ◽  
Liquid Culture Medium ◽  
Leucocrystal Violet ◽  
Purple Color

A detection method for histamine-producing, dairy-related bacteria was developed that involves a two-step sequential enzyme system. First, isolated bacteria are incubated in MRS broth or trypticase soy broth fortified with histidine. The histamine formed during this incubation period is reacted with diamine oxidase, which catalyzes the oxidation of histamine to form imidazole acetaldehyde, ammonia, and hydrogen peroxide. The hydrogen peroxide is then detected by the formation of crystal violet from the leuco base in the presence of horseradish peroxidase. Liquid culture medium containing bacteria that produce greater than 1200 nmole histamine per ml will develop a positive purple color. Cultures containing bacteria that produce little or no histamine will not develop a purple color. Other amines often found in cheese, such as tyramine, cadaverine, or putrescine, will not interfere with the color formation.

The degradation of p-toluenesulfonate by a Pseudomonas

1970 ◽  
Vol 16 (5) ◽  
pp. 309-316 ◽  
Author(s):  
D. D. Focht ◽  
F. D. Williams
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Aromatic Compounds ◽  
Carbon Sources ◽  
Sole Source ◽  
Carbon Chain ◽  
Ring Cleavage ◽  
Resting Cells ◽  
Resting Cell ◽  
Complete Mineralization

A Pseudomonas isolated from sewage was adapted to use p-toluenesulfonate as the sole source of both carbon and sulfur. Very few of over 30 aromatic compounds tested were used for growth as sole carbon sources. Significantly, sulfobenzoate, phenolsulfonates, and isomers of cresolsulfonates did not support growth. Respirometry studies with washed, resting cells showed similar results. In both studies, benzenesulfonate was always used more rapidly than p-toluenesulfonate. The degradation of p-toluenesulfonate was shown to be over 90% of the theoretical value required for complete mineralization to carbon dioxide, water, and sulfate. When resting cells were incubated with 35S-p-toluenesulfonate, the ratio of oxygen uptake to 35S-sulfate liberation remained constant during the complete degradation period. Radiochromatographic analysis showed no 35S-aromatic intermediates in resting-cell supernatants at any time. Resting cells previously incubated with 35S-p-toluenesulfonate liberated two 35S-labeled aromatic intermediates upon disruption. Resting cells incubated with 1-14C-p-toluenesulfonate produced labeled 3-methylcatechol, labeled acetate, and unlabeled pyruvate. The labeled intermediate, 3-methylcatechol, was degraded by cell-free extracts to labeled acetate. Hydroxylation, desulfonation, ring cleavage, and subsequent fissions of the carbon chain occurred in that order; all steps but the first were catalyzed by cell-free extracts.

Phosphoenolpyruvate-Dependent Glucose Transport in Oral Streptococci

1973 ◽  
Vol 52 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
Charles F. Schachtele ◽  
John A. Mayo
Keyword(s):  
Glucose Uptake ◽  
Streptococcus Mutans ◽  
Glucose Transport ◽  
Enzyme System ◽  
Cell Suspensions ◽  
Oral Streptococci ◽  
Phosphotransferase System ◽  
Resting Cell

Streptococcus mutans, S sanguis, and S salivarius use a phosphoenolpyruvate (PEP)-dependent phosphotransferase system that results in phosphorylation of glucose at carbon 6. This enzyme system is not sensitive to fluoride. Glucose uptake into resting cell suspensions is sensitive to fluoride because of inhibition of intracellular PEP production. The glucose phosphotransferase system is constitutive in oral streptococci.

SUBSTRATE-DEPENDENT PHOSPHORYLATION IN RESTING CELLS OF PSEUDOMONAS AERUGINOSA

1961 ◽  
Vol 7 (1) ◽  
pp. 91-97
Author(s):  
G. A. Strasdine ◽  
J. J. R. Campbell ◽  
H. P. C. Hogenkamp ◽  
J. N. Campbell
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Electron Transport Chain ◽  
Phosphate Uptake ◽  
Growth Yield ◽  
Resting Cells ◽  
Resting Cell ◽  
Transport Chain ◽  
Oxidation Of Glucose ◽  
Phosphate Incorporation ◽  
Stimulation Of

Resting cell suspensions of Pseudomonas aeruginosa exhibited substrate-dependent phosphorylation and most of the phosphate appeared in the nucleic acid fraction. The amount of P32 incorporated was a function of substrate concentration. When equivalent amounts of glucose, gluconate, or 2-ketogluconate were used as substrate, it was found that the more oxidized substrates supported appreciably less P32 incorporation, thus indicating that phosphorylation is coincident with the passage of electrons to oxygen by way of the electron transport chain. These data serve to illustrate that the practice of determining the amount of energy available from the dissimilation of a substrate by measuring growth yield can be in error since equivalent quantities of glucose, gluconate, and 2-ketogluconate supported equal amounts of growth. The P:O ratios obtained with glucose as substrate were of the order of 0.01. Phosphorylation was not sensitive to dinitrophenol or sodium fluoride but was completely inhibited by cyanide. Chloramphenicol, at a concentration which inhibited protein synthesis, caused a twofold stimulation of phosphate incorporation. Pyocyanine, which stops the oxidation of glucose at the 2-ketogluconate stage, completely inhibited phosphate uptake. The action of pyocyanine on both oxidation and phosphorylation could be reversed by magnesium. When extracts of this organism were studied, it was found that under all conditions the addition of oxidizable substrates decreased P32 incorporation.

scholarly journals The glycosulphatase of Trichoderma viride

1968 ◽  
Vol 108 (3) ◽  
pp. 393-399 ◽  
Author(s):  
A G Lloyd ◽  
P J Large ◽  
M Davies ◽  
A H Olavesen ◽  
K S Dodgson
Keyword(s):  
Culture Medium ◽  
Enzyme System ◽  
Trichoderma Viride ◽  
Defined Medium ◽  
Potassium Sulphate ◽  
Experimental Conditions ◽  
Lag Period

The growth of the mould Trichoderma viride on a defined medium containing either potassium d-glucose 6-O-sulphate or potassium d-galactose 6-O-sulphate as sole sources of both carbon and sulphur is marked by the production of an enzyme system capable of liberating inorganic SO42− ions from either of the sulphate esters. The enzyme is not produced when the organism is grown with glucose (or galactose) and potassium sulphate or with glucose and methionine as sole sources of carbon and sulphur. Experimental conditions are described whereby inorganic SO42− ions liberated from potassium glucose 6-O-sulphate by the growing mould appear in the culture medium after a constant lag period of 21–24hr. The enzyme has been shown to be a simple glycosulphatase that is active towards the 6-O-sulphate esters of d-glucose and d-galactose but not towards potassium glucose 3-O-sulphate. The properties of the crude glycosulphatase show the enzyme to be appreciably different from analogous molluscan enzymes that can degrade monosaccharide sulphate esters.

scholarly journals The Avr (Effector) Proteins HrmA (HopPsyA) and AvrPto Are Secreted in Culture from Pseudomonas syringaePathovars via the Hrp (Type III) Protein Secretion System in a Temperature- and pH-Sensitive Manner

1999 ◽  
Vol 181 (16) ◽  
pp. 4790-4797 ◽  
Author(s):  
Karin van Dijk ◽  
Derrick E. Fouts ◽  
Amos H. Rehm ◽  
Angela R. Hill ◽  
Alan Collmer ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Culture Medium ◽  
Secretion System ◽  
Effector Proteins ◽  
Accessory Proteins ◽  
Protein Traffic ◽  
Protein Secretion System ◽  
Type Iii Protein Secretion ◽  
Optimized Conditions ◽  
Culture Supernatants

ABSTRACT We present here data showing that the Avr proteins HrmA and AvrPto are secreted in culture via the native Hrp pathways fromPseudomonas syringae pathovars that produce these proteins. Moreover, their secretion is strongly affected by the temperature and pH of the culture medium. Both HrmA and AvrPto were secreted at their highest amounts when the temperature was between 18 and 22°C and when the culture medium was pH 6.0. In contrast, temperature did not affect the secretion of HrpZ. pH did affect HrpZ secretion, but not as strongly as it affected the secretion of HrmA. This finding suggests that there are at least two classes of proteins that travel theP. syringae pathway: putative secretion system accessory proteins, such as HrpZ, which are readily secreted in culture; and effector proteins, such as HrmA and AvrPto, which apparently are delivered inside plant cells and are detected in lower amounts in culture supernatants under the appropriate conditions. Because HrmA was shown to be a Hrp-secreted protein, we have changed the name ofhrmA to hopPsyA to reflect that it encodes a Hrp outer protein from P. syringae pv. syringae. The functional P. syringae Hrp cluster encoded by cosmid pHIR11 conferred upon P. fluorescens but not Escherichia coli the ability to secrete HopPsyA in culture. The use of these optimized conditions should facilitate the identification of additional proteins traveling the Hrp pathway and the signals that regulate this protein traffic.

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