The effects of external pH, temperature, and substrate concentration on acid phosphatase activity of ectomycorrhizal fungi

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.

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.


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.


1952 ◽  
Vol 30 (1) ◽  
pp. 1-9
Author(s):  
G. E. Delory ◽  
Merle Hetherington

The effect of dilution on the apparent acid phosphatase activity of undialyzed and dialyzed urine has been studied. In the former case, the apparent activity increases with dilution but this anomaly is removed by a preliminary dialysis. A convenient method for the determination of acid phosphatase based on this observation is described.


1971 ◽  
Vol 13 (2) ◽  
pp. 298-305 ◽  
Author(s):  
M. Mohan Reddy ◽  
S. F. H. Threlkeld

Mycelial extracts of 34 strains representing eight species of the genus Neurospora were subjected to acrylamide and starch gel electrophoresis to detect sites of esterase, lactate dehydrogenase, amylase, peroxidase, and acid phosphatase activity. Nine isozymes of esterases, four isozymes of lactate dehyrogenases, three isozymes of peroxidases, and two isozymes of acid phosphatases were detected on the gels for the species. The application of zymograms as a biochemical means to characterize species is discussed.


1965 ◽  
Vol 24 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Jacob J. Blum

When a bleached strain of Euglena is maintained in a medium containing very low con centrations of phosphate, the acid phosphatase activity increases. The increase in acid phosphatase activity is prevented by Actinomycin D and by p-fluorophenylalanine (PFA), indicating that the increased activity is due to de novo synthesis of acid phosphatase. When phosphate is replenished, the acid phosphatase activity decreases to the level characteristic of uninduced cells before there is any appreciable cell division. When cell division resumes in the presence of PFA, the level of acid phosphatase activity remains approximately constant. This indicates that there are two different phosphatases: a constitutive enzyme, whose synthesis is insensitive to the presence of PFA, and an induced enzyme, whose synthesis is sensitive to PFA. These enzymes are not equally sensitive to changes in pH and in fluoride concentration, thus permitting them to be assayed individually in whole toluene-treated cells. Induced cells also acquire the ability to remove phosphate from the medium very rapidly.


1964 ◽  
Vol 45 (3) ◽  
pp. 476-486 ◽  
Author(s):  
Claes Hellerström ◽  
Inge-Bert Täljedal ◽  
Bo Hellman

ABSTRACT Quantitative studies of non-specific acid phosphatases were performed on isolated pancreatic islets from obese-hyperglycaemic mice. The islets of these animals are composed of a rather pure population of B cells. The following observations were made: Acid phosphatases originating in the islet tissue, showed maximal enzyme activities at about pH 3.5 and 5.3 using p-nitrophenyl phosphate as substrate. The acid phosphatase activity of the exocrine tissue showed a single distinct maximum at about pH 5.3. The islet acid phosphatases were inhibited by sodium fluoride, sodium tartrate and formaldehyde. They were stable against storage in crude tissue homogenates at + 4° C and + 20° C for 48 hours. The pancreatic islets exhibited a significantly higher acid phosphatase activity than the exocrine parenchyma. Starvation for 7 days did not alter the enzyme levels in the islets or acini when measured at pH 5.3, while a probably increased enzyme activity was obtained in both these regions at pH 3.5. There was no evidence for a relationship between the insulin secretion and the acid phosphatase activity of the B cells.


1961 ◽  
Vol 39 (4) ◽  
pp. 737-738 ◽  
Author(s):  
G. E. Delory ◽  
Merle Hetherington

The inhibitory effect of 0.5% formalin and of 0.02 ML-tartaric acid has been studied on the acid phosphatase activity of a number of human tissue extracts. It was found that the sum of the formalin resistant and of the tartaric acid resistant enzyme activity closely approximated the activity of the uninhibited enzyme.


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.


2007 ◽  
Vol 190 (4) ◽  
pp. 1459-1472 ◽  
Author(s):  
Todd C. Hoopman ◽  
Wei Wang ◽  
Chad A. Brautigam ◽  
Jennifer L. Sedillo ◽  
Thomas J. Reilly ◽  
...  

ABSTRACT Moraxella catarrhalis O35E was shown to synthesize a 105-kDa protein that has similarity to both acid phosphatases and autotransporters. The N-terminal portion of the M. catarrhalis acid phosphatase A (MapA) was most similar (the BLAST probability score was 10−10) to bacterial class A nonspecific acid phosphatases. The central region of the MapA protein had similarity to passenger domains of other autotransporter proteins, whereas the C-terminal portion of MapA resembled the translocation domain of conventional autotransporters. Cloning and expression of the M. catarrhalis mapA gene in Escherichia coli confirmed the presence of acid phosphatase activity in the MapA protein. The MapA protein was shown to be localized to the outer membrane of M. catarrhalis and was not detected either in the soluble cytoplasmic fraction from disrupted M. catarrhalis cells or in the spent culture supernatant fluid from M. catarrhalis. Use of the predicted MapA translocation domain in a fusion construct with the passenger domain from another predicted M. catarrhalis autotransporter confirmed the translocation ability of this MapA domain. Inactivation of the mapA gene in M. catarrhalis strain O35E reduced the acid phosphatase activity expressed by this organism, and this mutation could be complemented in trans with the wild-type mapA gene. Nucleotide sequence analysis of the mapA gene from six M. catarrhalis strains showed that this protein was highly conserved among strains of this pathogen. Site-directed mutagenesis of a critical histidine residue (H233A) in the predicted active site of the acid phosphatase domain in MapA eliminated acid phosphatase activity in the recombinant MapA protein. This is the first description of an autotransporter protein that expresses acid phosphatase activity.


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