Ectomycorrhizal fungi of Salix rotundifolia III. Resynthesized mycorrhizal complexes and their surface phosphatase activities

1981 ◽  
Vol 59 (12) ◽  
pp. 2458-2465 ◽  
Author(s):  
R. K. Antibus ◽  
J. G. Croxdale ◽  
O. K. Miller ◽  
A. E. Linkins

Pure culture isolates were obtained from fungi fruiting in the vicinity of dwarf willows at Barrow and Cape Simpson, Alaska. Four of these isolates and one isolate from Maryland were tested for their ability to form ectomycorrhizae with cuttings of Salix rotundifolia under controlled environmental conditions. Isolates of Entoloma sericeum, Hebelomapusillum, and Cenococcum geophilum from Barrow and Cape Simpson, Alaska all formed typical ectomycorrhizae with S. rotundifolia, while an isolate of C. geophilum from a temperate ecosystem (Maryland) did not.All of the ectomycorrhizae synthesized with S. rotundifolia, plus uncolonized roots, demonstrated an ability to hydrolyze p-nitrophenyl phosphate at a pH of 4.7. The acid phosphatase activity of E. sericeum ectomycorrhizae was from 10 to 40 times as great as that demonstrated by other mycorrhizal and nonmycorrhizal roots on a surface area basis.

1965 ◽  
Vol 22 (3) ◽  
pp. 793-799 ◽  
Author(s):  
N. J. Antia ◽  
A. Watt

Evidence has been obtained for acid phosphatase activity (on p-nitrophenyl phosphate as substrate) at pH 4.8 in cell-free extracts of Phaeodactylum tricornutum, Skeletonema costatum, Cyclotella nana, Monochrysis lutheri, Isochrysis galbana, and Dunaliella tertiolecta grown photo-autotrophically in pure culture. No alkaline phosphatase activity at pH 10.5 was observed.


1979 ◽  
Vol 57 (11) ◽  
pp. 1203-1205 ◽  
Author(s):  
Iwan Ho ◽  
Bratislav Zak

Six ectomycorrhizal fungi commonly associated with Douglas-fir were tested in vitro for acid phosphatase activity by measuring the amount of p-nitrophenyl phosphate converted to p-nitrophenol and by examining their production of isoenzymes detectable by starch gel electrophoresis. Both test methods showed acid phosphatase activity to be highest in Hebeloma crustuliniforme, followed by progressively lower activity in Laccaria laccata, Amanita muscaria, and Thelephora terrestris. Rhizopogon vinicolor and Piloderma bicolor showed low activity. We discuss the significance of these fungi in the utilization of complex phosphates by tree roots.


1986 ◽  
Vol 64 (11) ◽  
pp. 2383-2387 ◽  
Author(s):  
Robert K. Antibus ◽  
Carolyn J. Kroehler ◽  
Arthur E. Linkins

Isolates of the ectomycorrhizal fungi Cenococcum geophilum, Hebeloma pusillum, and Entoloma sericeum were grown in axenic culture to study the effects of assay pH, temperature, and substrate concentration on the activity of surface acid phosphatases. In addition, isolates were grown at 12 and 20 °C to determine whether the Arrhenius activation energies of surface phosphatases were affected by temperature acclimation. Four of the six isolates examined demonstrated distinct pH optima at pH 5.0; one isolate showed optimal activity at pH 4.5. None of the fungi examined produced significant surface alkaline phosphatase activity. Arrhenius activation energy values were not affected by lowering the growth temperature, suggesting that a phenotypic change in surface acid phosphatases did not occur with acclimation. Vmax and Km values for the hydrolysis of p-nitrophenyl phosphate were found to differ significantly among the isolates examined. Our findings support previous research by confirming the existence of interspecific and intraspecific differences in acid phosphatase activity, but they demonstrate the importance of considering assay pH and substrate concentration when making such comparisons.


1989 ◽  
Vol 67 (3) ◽  
pp. 750-753 ◽  
Author(s):  
Iwan Ho

Seventeen isolates, encompassing five genera and eight species of ectomycorrhizal fungi, were compared for acid phosphatase, alkaline phosphatase, and nitrate reductase activity. Isolates within species differed in enzyme activity and isozyme patterns by host specificity and site (as exemplified by the genus Suillus). Host and site may have affected phosphatase enzyme activity. Generally, the Douglas-fir associates, which dominate in mesic sites, have higher acid phosphatase activity than pine associates, which mostly occupy xeric sites; however, pine associates from mesic sites also have higher acid phosphatase activity (e.g., S. tomentosus). In four isolates of Amanita muscaria, the effect of site was also apparent. Two of them, which have significantly higher acid phosphatase activity than the others, were isolated from mesic sites. The isozyme pattern of the genus Suillus appeared to be separated by host groups. Other isolates with only one species also differed more or less by host groups. They shared at least one band within host groups, except for the two isolates of Paxillus involutus from different hosts. The P. involutus S-403 isolated from an orchard showed much higher nitrate reductase activity than all other isolates. No apparent differences in nitrate reductase activity were found between the other isolates.


1984 ◽  
Vol 30 (1) ◽  
pp. 8-15 ◽  
Author(s):  
John D. DuBois ◽  
Keith R. Roberts ◽  
Lawrence A. Kapustka

Polyphosphate bodies and acid phosphatase activity were characterized in Nostoc sp. to determine if the hydrolysis of polyphosphate bodies occurs during dark (energy stress) periods. Electron and light microscopy were used to locate polyphosphate bodies. Acid phosphatase activity was measured using p-nitrophenyl phosphate as the substrate to determine net changes in the level of the enzyme activity. To induce energy stress, Nostoc sp. cells were kept in the dark for 72 h to deplete stored carbon compounds. Cells incubated in the light for 72 h (controls) showed acid phosphatase activity localized around the perimeter of polyphosphate bodies. When cells were incubated in the dark, acid phosphatase activity occurred throughout the polyphosphate body matrix. However, complete hydrolysis of the polyphosphate body did not occur and the rate of acid phosphatase activity was not affected.


1974 ◽  
Vol 22 (12) ◽  
pp. 1092-1104 ◽  
Author(s):  
ATSUSHI KOMIYAMA ◽  
SAMUEL S. SPICER

Bone marrow basophils incubated in Gomori medium at pH 6.0-6.8 exhibited strong acid phosphatase activity suggestive of a potential role in endocytosis in one-third of the cytoplasmic granules and also in Golgi elements. Buffy coat basophils contained about one-third as many reactive granules. Reaction product was confined to the threadlike component of the larger granules predominant in early basophils and was absent from the denser-type granules predominant in late basophils. In centrioles of basophils acid phosphatase appeared localized between triplet fibers. Reactivity with the Gomori medium was diminished at pH 5.0, absent at pH 8.0 and only slightly decreased with p-nitrophenyl phosphate as substrate. Basophils incubated in Barka-Anderson medium at pH 5.0-6.8 revealed light acid phosphatase activity in the Golgi lamellae but essentially none in cytoplasmic granules. Tris-maleate buffer of the Barka-Anderson medium replacing the sodium acetate of the Gomori medium inhibited the reactivity in the granules. Incubation in media containing NaF, or lacking substrate, eliminated the heavy precipitates in granules and Golgi elements but yielded light, nonenzymatic lead staining in Golgi and tubulovesicular structures and atypical granules present only in buffy coat basophils.


1975 ◽  
Vol 42 (2) ◽  
pp. 327-339 ◽  
Author(s):  
A. T. Andrews ◽  
E. Alichanidis

SummaryThe acid phosphatase activity levels in a number of Greek cheeses and in Cheddar cheeses were found to be unaffected by storage for up to 18 months and 12 months respectively. In Cheddar cheese, starter organisms made an insignificant contribution to this activity. Studies of acid phosphatase prepared from Streptococcus cremoris-lactis NCDO 762 starter cultures showed that the enzyme was of high molecular weight and largely particle-bound. The pH of optimum activity was 5·2 and the enzyme was inhibited by F−, Al3+, a number of heavy metals, oxidizing agents and sulphydryl-modifying reagents. Kinetic measurements at pH 5·2 gave a Km value for p-nitrophenyl phosphate of 1·2 mM. Orthophosphate, pyrophosphate and isoelectrically precipitated casein behaved as competitive inhibitors to the hydrolysis of p-nitrophenyl phosphate with K1 values of 1·2 mM, 1·0 mM and 1·1 mM respectively. In spite of this binding to the enzyme, casein provided a very poor substrate for the starter acid phosphatase. The properties of acid phosphatase present in Cheddar cheese made with Str. cremoris NCDO 924 starter were consistent with the enzyme being exclusively of milk origin and small differences between this and the acid phosphatase previously isolated from bovine milk were attributable to the binding of peptides produced during the cheese maturation to the enzyme molecules. It was concluded that in cheese, phosphatase action was due largely to the enzyme of milk origin, with that provided by the starter being of minor importance.


1991 ◽  
Vol 69 (2) ◽  
pp. 380-383 ◽  
Author(s):  
Janet MacFall ◽  
Steven A. Slack ◽  
Jaya Iyer

The ectomycorrhizal fungus Hebeloma arenosa Burdsall, MacFall & Albers was assayed for surface-accessible acid phosphatase activity in vitro on roots of red pine (Pinus resinosa Ait.) seedlings. Hebeloma arenosa was grown in defined liquid media containing 0, 17, 34, 68, or 136 mg/L phosphorus for 4 weeks. When assayed for acid phosphatase activity with p-nitrophenyl phosphate, 7.3 μmol of orthophosphate were released per gram dry weight of fungal tissue. There was no effect of added P on enzyme activity, excluding the treatment with no added P in which there was negligible fungal growth. Red pine seedlings were grown in Sparta loamy fine sand amended with 0, 17, 34, 68, or 136 mg/kg P as superphosphate, with and without H. arenosa inoculum. Mycorrhizal roots had greater enzyme activity than nonmycorrhizal roots of seedlings grown in similarly P-amended soil. This was determined by the following three assays: orthophosphate release from two salts of myoinosital hexaphosphate (Na and KMg) and from p-nitrophenyl phosphate. It is suggested that greater acid phosphatase activity by roots mycorrhizal with H. arenosa is one mechanism for improved P nutrition through the formation of a pool of P released from sources unavailable for direct intake.


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