ISSN:
1573-5117
Keywords:
lake
;
bacteria
;
microalgae
;
alkalinephosphatase activity
;
seasonal and diel changes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Seasonal changes in alkalinephosphatase activity of bacteria and microalgae werestudied in the dimictic Lake Pavin (Massif Central,France), to test whetherthis activity is primarily algal or bacterial andwhether the APA presents seasonal variations coupledwith abiotic and biotic variables. Samples werecollected at different depths from May 1992 to May1993. The specific phosphatase activities wereanalysed spectrophotometrically with p-NitrophenylPhosphate (p-NPP) as substrate and were related to theprotein concentrations. No correlation was foundbetween alkaline phosphatase activity and solublereactive phosphorus (SRP) concentrations across anannual cycle. The specific activities of the smallclass (0.2–1.2 μm) were the highest and thecontribution of this picoplanktonic size class(0.2–1.2 μm) increased with depth. In addition, thelinear correlations between alkaline phosphataseactivity and protein concentration seemed to indicatethat most of these enzymes are constitutive. However,it cannot be excluded that the high phosphorusconcentrations repress APA.Finally, the measure of APA does not seem to be avalid quantitative test of the deficiency ofphosphorus for aquatic microorganisms.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1003044008455
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