title: EXTRACTIVE AND ENZYMATIC ANALYSES FOR LIMITING OR SURPLUS PHOSPHORUS IN ALGAE.
abstract: An extractive procedure for detection of surplus-stored phosphorus (luxury consumption) in algae and an enzymatic analysis for conditions of P-limited growth in algae have been evaluated. A simple 60-min boiling water extraction of algae known to contain surplus P separates essential P compounds and surplus-stored P compounds. Surplus P compounds can be measured in the extract as orthophosphate. Extracts of algae limited in their growth by the amount of available P contain little or no orthophosphate. Limitation of algal growth by P supply induces the enzyme alkaline phosphatase. The activity of this enzyme can be measured at pH 9 using p-nitro-phenylphosphate as substrate. Algae which were P-limited and contained no extractable orthophosphate have as much as 25 times more alkaline phosphatase activity than algae with surplus available P.
authors.affiliation: Water Chemistry Laboratory, University of Wisconsin, Madison, WisconsinMcArdle Memorial Laboratory, University of Wisconsin, Madison, Wisconsin.
authors.forename: G P
authors.initials: GP
authors.lastname: Fitzgerald
authors.affiliation: Water Chemistry Laboratory, University of Wisconsin, Madison, WisconsinMcArdle Memorial Laboratory, University of Wisconsin, Madison, Wisconsin.
authors.forename: T C
authors.initials: TC
authors.lastname: Nelson