UPTAKE KINETICS AND STORAGE CAPACITY OF DISSOLVED INORGANIC PHOSPHORUS AND CORRESPONDING N: P DYNAMICS IN&IT ULVA LACTUCA &IT(CHLOROPHYTA)

Alexander Lubsch*, Klaas Timmermans

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

14 Citaten (Scopus)
43 Downloads (Pure)

Samenvatting

Dissolved inorganic phosphorus (DIP) is an essential macronutrient for maintaining metabolism and growth in autotrophs. Little is known about DIP uptake kinetics and internal P-storage capacity in seaweeds, such as Ulva laduca (Chlorophyta). Ulva laduca is a promising candidate for biofiltration purposes and mass commercial cultivation. We exposed U. laduca to a wide range of DIP concentrations (1-50 mu mol center dot L-1 and a nonlimiting concentration of dissolved inorganic nitrogen (DIN; 5,000 mu mol center dot L-1 ) under fully controlled laboratory conditions in a "pulse-and-chase" assay over 10 d. Uptake kinetics were standardized per surface area of U. lactual fronds. Two phases of responses to DIP-pulses were measured: (i) a surge uptake (V-s) of 0.67 +/- 0.10 mu mo] center dot cm(-2) center dot d(-1) and (ii) a steady state uptake (V-M ) of 0.07 +/- 0.03 mu mol center dot cm(-2)center dot d(-1) . Mean internal storage capacity (ISCp) of 0.73 +/- 0.13 mu mol center dot cm(-2) was calculated for DIP. DIP uptake did not affect DIN uptake. Parameters of DIN uptake were also calculated: V-s = 12.54 +/- 1.90 mu mol center dot cm(-2) center dot d(-1), V-M = 2.26 +/- 0.86 mu mol center dot cm(-2) center dot d(-1) , and ISCN = 22.90 +/- 6.99 mu mol center dot cm(-2) . Combining ISC and V-M values of P and N, nutrient storage capacity of U. lactuca was estimated to be sufficient for similar to 10 d. Both P and N storage capacities were filled within 2 d when exposed to saturating nutrient concentrations, and uptake rates declined thereafter at 90% for DIP and at 80% for DIN. Our results contribute to understanding the ecological aspects of nutrient uptake kinetics in U. lactuca and quantitatively evaluating its potential for bioremediation and/or biomass production for food, feed, and energy.

Originele taal-2English
Pagina's (van-tot)215-223
Aantal pagina's9
TijdschriftJournal of Phycology
Volume54
Nummer van het tijdschrift2
DOI's
StatusPublished - apr.-2018

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