EXTRACTIVE AND ENZYMATIC ANALYSES FOR LIMITING OR SURPLUS PHOSPHORUS IN ALGAE.

Area of Science:

• Environmental Science
• Biochemistry
• Algal Biology

Background:

• Phosphorus (P) is a critical nutrient for algal growth, and its availability influences algal physiology and enzyme production.
• Understanding phosphorus storage and limitation is essential for managing algal blooms and aquatic ecosystems.

Purpose of the Study:

• To evaluate an extractive procedure for detecting surplus-stored phosphorus (luxury consumption) in algae.
• To assess an enzymatic analysis for identifying phosphorus-limited growth conditions in algae.

Main Methods:

• A 60-minute boiling water extraction was used to separate essential and surplus-stored phosphorus compounds in algae.
• Surplus phosphorus was quantified as orthophosphate in the algal extract.
• Alkaline phosphatase enzyme activity was measured at pH 9 using p-nitro-phenylphosphate as a substrate to indicate P-limited growth.

Main Results:

• The boiling water extraction effectively separated and allowed measurement of surplus-stored phosphorus as orthophosphate.
• Algae experiencing phosphorus limitation contained little to no extractable orthophosphate.
• Phosphorus-limited algae exhibited up to 25 times higher alkaline phosphatase activity compared to algae with surplus phosphorus.

Conclusions:

• Boiling water extraction is a viable method for detecting surplus phosphorus in algae.
• Alkaline phosphatase activity serves as a reliable indicator of phosphorus-limited growth conditions in algae.
• These methods provide valuable tools for assessing phosphorus dynamics in algal populations.