Rhizobitoxine production by and nodulation characteristics of colony-type derivatives of Bradyrhizobium japonicum USDA 76

1988 ◽  
Vol 34 (8) ◽  
pp. 1017-1022 ◽  
Author(s):  
Jeffrey S. La Favre ◽  
Adrienne K. La Favre ◽  
Allan R. J. Eaglesham
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Functional Relationship ◽  
Ruthenium Red ◽  
Broth Culture ◽  
Colony Type ◽  
Major Function ◽  
Large Colony ◽  
Small Colony ◽  
Derivatives Of

Bradyrhizobium japonicum strain USDA 76, a rhizobitoxine producer, was found to contain two colony types, designated "small" and "large" based on colony size on agar medium. Only the small type produced detectable chlorosis-inducing toxin in culture, whereas both colony types induced chlorosis as a result of synthesis of toxin in nodules. Electron microscopy revealed that a large colony derivative, grown in broth culture, was encapsulated, whereas a small colony derivative was not, suggesting a negative functional relationship between toxin synthesis and presence of capsule. The large type also had a ruthenium red reactive extracellular layer when cultured in the soybean rhizosphere. This differential production of toxin by the colony derivatives in culture, and presumably in the rhizosphere, prompted the investigation of a proposed role of rhizobitoxine in the infection of roots of nodulation-refractory (rj1rj1) soybean; the small colony type formed fewer nodules on the (rj1rj1) isoline, indicating no major function for rhizobitoxine in the infection of (rj1rj1) soybean.

Comparison of colony morphology, salt tolerance, and effectiveness in Rhizobium japonicum

1977 ◽  
Vol 23 (9) ◽  
pp. 1118-1122 ◽  
Author(s):  
Robert G. Upchurch ◽  
Gerald H. Elkan
Keyword(s):  
Nitrogen Fixation ◽  
Growth Rates ◽  
Host Plants ◽  
Symbiotic Nitrogen Fixation ◽  
Rhizobium Japonicum ◽  
Free Living ◽  
Relative Level ◽  
Colony Type ◽  
Large Colony ◽  
Small Colony

Four strains of Rhizobium japonicum, two of which produce slimy and non-slimy colony types and two others which produce large and small colony types, were isolated and cloned. All were infective and nodulated Lee soybean host plants. Each colony type was characterized as to its salt sensitivity to Na+ and K+ ions, relative level of symbiotic nitrogen fixation, and relative level of free-living nitrogen fixation. Growth studies performed in the presence of salts demonstrated that the non-slimy or small colony types were sensitive to salt with significantly depressed growth rates and cell yields. Growth rates and cell yields of slimy, large, colony types were relatively unaffected by salt. Both symbiotic and free-living (non-associative) nitrogen fixation analyses (by acetylene reduction) revealed that the non-slimy, small colonies were significantly more effective than slimy, large colonies.

Colonial variation in Xanthomonas campestris NRRL B-1459 and characterization of the polysaccharide from a variant strain

1976 ◽  
Vol 22 (7) ◽  
pp. 942-948 ◽  
Author(s):  
M. C. Cadmus ◽  
S. P. Rogovin ◽  
K. A. Burton ◽  
J. E. Pittsley ◽  
C. A. Knutson ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Extracellular Polysaccharide ◽  
Variant Form ◽  
Glucose Content ◽  
Colony Type ◽  
Molar Ratios ◽  
Large Colony ◽  
Predominant Variant ◽  
Small Colony

Stock cultures of Xanthomonas campestris NRRL B-1459 require special attention to maintenance and propagation to assure consistent production in good yields of the extracellular polysaccharide xanthan. Under customary conditions of propagative maintenance on agar slants, variant colony types develop that are smaller in size than the normal type. The rate of regression of the normal to the variant forms was diminished when the D-glucose content of the stock medium was sufficient to avoid depletion during storage and when transfer to fresh medium was reduced to 14-day intervals. Under conditions for polysaccharide production, the normal large-colony type gives crude culture liquors after 48 h of 7000 centipoise (cp) viscosity; the predominant variant form gives only 4000 cp. On the basis of 2.1% initial D-glucose, biopolymer yields for the normal and variant strains were 62 and 43%, respectively. Polysaccharide produced by the variant (small-colony type) differs adversely in solution properties from that of the parent strain (large-colony type); it differs also in its lower content of pyruvic acid and O-acetyl substituents. The molar ratios of constituent sugars (D-glucose, D-mannose, and D-glucuronic acid), however, were identical in polysaccharides with the normal and variant strains. Exclusion of colonial variants from fermentations is prerequisite to production of xanthan optimum in properties and yield.

scholarly journals A study of F38-type and related mycoplasmas by mycoplasmaemia and cross-immunization tests in mice

1984 ◽  
Vol 93 (3) ◽  
pp. 465-473 ◽  
Author(s):  
M. Kanyi Kibe ◽  
G. R. Smith
Keyword(s):  
Cross Protection ◽  
Partial Protection ◽  
Colony Type ◽  
Mycoplasma Capricolum ◽  
Large Colony ◽  
Strain Nctc ◽  
History Of ◽  
Small Colony ◽  
Type Strains

SummaryIn vivo methods were used to study the F38-type mycoplasma in parallel with related mycoplasmas.Three of five strains of ‘bovine serogroup 7’ with an unknown history of subculture produced mycoplasmaemia in mice inoculated intraperitoneally. A strain of ‘bovine serogroup L’ also produced mycoplasmaemia, but no evidence of similar ability could be found for single strains of Mycoplasma capricolum, M. equigenitalium and M. primatum, or for two strains of the F38-type mycoplasma.In cross-immunization tests a bovine serogroup 7 strain (NCTC 10133) and a strain (‘Blenheim’) of the SC (small colony) type of M. mycoides subsp. mycoides were used for the purpose of challenge. Cross-protection was described as ‘complete’ or ‘partial’, depending on whether it was as great as, or less than, that produced by homologous vaccine. Although strain NCTC 10133 protected strongly, possibly completely, against Blenheim, and Blenheim gave partial protection against NCTC 10133, challenge with NCTC 10133 and Blenheim gave strikingly different results. Thus (1) F38-type strains, M equigenitalium and M. primatum all gave partial cross-protection against NCTC 10133 but not against Blenheim, (2) NCTC 10133, unlike Blenheim, was seldom susceptible to partial cross-protection by LC (large colony) strains of M. mycoides subsp. mycoides, and (3) three SC strains – which would have protected completely against Blenheim – protected only partially against NCTC 10133. NCTC 10133 and Blenheim were similar, however, in that M. capricolum and M. mycoides subsp. capri failed to cross-protect against them both.

Differentiation of Rhizobium japonicum strain derivatives by antibiotic sensitivity patterns, lectin binding, and utilization of biochemicals

1980 ◽  
Vol 26 (5) ◽  
pp. 606-612 ◽  
Author(s):  
Michael C. Meyer ◽  
Steven G. Pueppke
Keyword(s):  
Parental Strain ◽  
Lectin Binding ◽  
Antibiotic Sensitivity ◽  
Colony Morphology ◽  
Rhizobium Japonicum ◽  
Large Colony ◽  
Utilization Patterns ◽  
Small Colony ◽  
Derivatives Of ◽  
Soybean Lectin

Several strains of Rhizobium japonicum have been reported to consist of mixtures of stable derivatives having distinct colony morphologies and physiological characteristics. We isolated derivatives from strains of R. japonicum and systematically compared them with previously isolated derivatives with respect to the utilization of biochemicals, antibiotic sensitivity, and soybean lectin binding. With the exception of a pair of derivatives from 3I1b 110, one of which utilized pyruvate and one of which did not, sibling derivatives had essentially identical biochemical utilization patterns. The sibling derivatives of parental strains 3I1b 110 and 3I1b 140 exhibited marked variation in their sensitivities to several antibiotics, including gentamicin, sulfamethoxazole, and tetracycline. Compared with the derivatives with small colony morphology, derivatives with large colony morphology were in general more sensitive to these antibiotics. With one exception, the binding of soybean lectin to the derivatives was quantitatively the same as that to the parental strain. The anomaly was 110-Y which, in contrast to its parental strain and sibling derivatives, failed to bind detectable amounts of the lectin. 110-Y, as well as all the other derivatives and parental strains, nodulated Disoy soybean.

The role of secondary alcoholic groups of D-galacturonan in its degradation with exo-D-galacturonanase

1980 ◽  
Vol 45 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Kveta Heinrichová ◽  
Rudolf Kohn
Keyword(s):  
Acetyl Derivative ◽  
Competitive Inhibitor ◽  
Hydroxyl Groups ◽  
Pectic Acid ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
The Individual ◽  
Degradation Degree ◽  
Derivatives Of

The effect of exo-D-galacturonanase from carrot on O-acetyl derivatives of pectic acid of variousacetylation degree was studied. Substitution of hydroxyl groups at C(2) and C(3) of D-galactopyranuronic acid units influences the initial rate of degradation, degree of degradation and its maximum rate, the differences being found also in the time of limit degradations of the individual O-acetyl derivatives. Value of the apparent Michaelis constant increases with increase of substitution and value of Vmax changes. O-Acetyl derivatives act as a competitive inhibitor of degradation of D-galacturonan. The extent of the inhibition effect depends on the degree of substitution. The only product of enzymic reaction is D-galactopyranuronic acid, what indicates that no degradation of the terminal substituted unit of O-acetyl derivative of pectic acid takes place. Substitution of hydroxyl groups influences the affinity of the enzyme towards the modified substrate. The results let us presume that hydroxyl groups at C(2) and C(3) of galacturonic unit of pectic acid are essential for formation of the enzyme-substrate complex.

Ein pseudoallel-spezifischer Suppressor bei Salmonella typhimurium

1956 ◽  
Vol 11 (6) ◽  
pp. 317-329 ◽  
Author(s):  
P. Starlinger ◽  
F. Kaudewitz
Keyword(s):  
Salmonella Typhimurium ◽  
Uv Irradiation ◽  
Genetic Material ◽  
Suppressor Gene ◽  
Growth Characteristics ◽  
Suppressor Mutation ◽  
Deficient Mutant ◽  
Colony Type ◽  
Gene Concept ◽  
Small Colony

In Salmonella typhimurium, UV-irradiation of the histidine-deficient mutant hi-31 induced a slowly growing reversion to histidine-independence. This formed colonies much smaller than wildtype. By means of transduction the newly created character “small colony” was proved to be heritable. As demonstrated by the following experiments this was due to an independant suppressor-mutation (S-31). After UV-irradiation of hi-31/S-31 a small fraction of cells forming large colonies, revealed growth-characteristics of wildtype. After transduction of small colony type cells by phages raised on wildtype the same large colonies were obtained. Expected to be of genotype hi-31+/S-31, they were used as donor for transduction of hi-31. Both, large colonies (hi-31+/S-31) and small colonies (hi-31/S-31) were isolated, which proved to be stable in further transfers.26 histidin-requiring mutants, belonging to 4 groups, each of them characterised by the same block in histidine synthesis, were transduced with phage raised on hi-31/S-31. None of them exhibited changes of growth characteristics, resulting from the incorporation of the suppressor-gene. Thus the suppressor S-31 turned out to be pseudoallel-specific.This result is considered as evidence that pseudoalleles of the histidine series in Salmonella typhimurium not only are units of recombination but also of function of genetic material. The differences between levels of functions exhibited by units which have been called pseudoalleles by various investigators are discussed in connection with the gene concept.

scholarly journals Ca2+ Microdomains, Calcineurin and the Regulation of Gene Transcription

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 875
Author(s):  
Gerald Thiel ◽  
Tobias Schmidt ◽  
Oliver G. Rössler
Keyword(s):  
Transcription Factors ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Gene Transcription ◽  
Intracellular Signaling ◽  
Second Messengers ◽  
Major Function ◽  
Surface Receptors ◽  
Dependent Protein

Ca2+ ions function as second messengers regulating many intracellular events, including neurotransmitter release, exocytosis, muscle contraction, metabolism and gene transcription. Cells of a multicellular organism express a variety of cell-surface receptors and channels that trigger an increase of the intracellular Ca2+ concentration upon stimulation. The elevated Ca2+ concentration is not uniformly distributed within the cytoplasm but is organized in subcellular microdomains with high and low concentrations of Ca2+ at different locations in the cell. Ca2+ ions are stored and released by intracellular organelles that change the concentration and distribution of Ca2+ ions. A major function of the rise in intracellular Ca2+ is the change of the genetic expression pattern of the cell via the activation of Ca2+-responsive transcription factors. It has been proposed that Ca2+-responsive transcription factors are differently affected by a rise in cytoplasmic versus nuclear Ca2+. Moreover, it has been suggested that the mode of entry determines whether an influx of Ca2+ leads to the stimulation of gene transcription. A rise in cytoplasmic Ca2+ induces an intracellular signaling cascade, involving the activation of the Ca2+/calmodulin-dependent protein phosphatase calcineurin and various protein kinases (protein kinase C, extracellular signal-regulated protein kinase, Ca2+/calmodulin-dependent protein kinases). In this review article, we discuss the concept of gene regulation via elevated Ca2+ concentration in the cytoplasm and the nucleus, the role of Ca2+ entry and the role of enzymes as signal transducers. We give particular emphasis to the regulation of gene transcription by calcineurin, linking protein dephosphorylation with Ca2+ signaling and gene expression.

Anomalous narrowing of the shape of the structural process in derivatives of trehalose at high pressure. The role of the internal structure

2021 ◽  
pp. 116321
Author(s):  
Dawid Heczko ◽  
Joanna Grelska ◽  
Karolina Jurkiewicz ◽  
Patrycja Spychalska ◽  
Anna Kasprzycka ◽  
...  
Keyword(s):  
High Pressure ◽  
Internal Structure ◽  
Structural Process ◽  
Derivatives Of
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