title: Role of DOP on the alkaline phosphatase activity of size fractionated plankton in coastal waters in the NW Mediterranean Sea (Toulon Bay, France).
abstract: The particulate material was fractionated into 5 size classes (>90μ, 50-90μ, 6-50μ, 1-6μ, and <1μ). DOP was analysed as easily (DOPh, DOPpa) and less easily hydrolysable compounds (DOPox). Based on Vmax, 94% of the high affinity AP activity was due to <50μ cells and 77% to <1μ cells. 83% of the low affinity activity was due to >90μ cells. The high affinity activities were negatively correlated with DOP for the <50μ classes. These correlations came mostly from DOPox. They were more significant when NO3+NO2concentrations were high, when DIP concentrations were low and when N/P ratio was >10. At lower N/P ratios, AP was more significantly correlated with DIP. The low affinity activities showed significant negative correlation with DIP and with DOP and DOPox for the >90μ class. The inhibition of AP activities by DOPox may originate from stable compounds interfering with DIP for the control of AP synthesis.
authors.affiliation: Laboratoire PROTEE-EBMA (EA 3819), Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France. Electronic address: boge@univ-tln.fr.
authors.forename: Gérard
authors.initials: G
authors.lastname: Bogé
authors.affiliation: Laboratoire PROTEE-EBMA (EA 3819), Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France. Electronic address: m_lespilette@yahoo.fr.
authors.forename: Magali
authors.initials: M
authors.lastname: Lespilette
authors.affiliation: Laboratoire PROTEE-EBMA (EA 3819), Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France. Electronic address: d.jamet@univ-tln.fr.
authors.forename: Dominique
authors.initials: D
authors.lastname: Jamet
authors.affiliation: Laboratoire PROTEE-EBMA (EA 3819), Université de Toulon, CS 60584, 83041 Toulon Cedex 9, France. Electronic address: jamet@univ-tln.fr.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Jamet
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D061006:Bays; D005602:France; D008522:Mediterranean Sea; D010758:Phosphorus / Q000737:chemistry*; D010933:Plankton / Q000201:enzymology*; D012623:Seawater / Q000737:chemistry*
chemical_list: D010758:Phosphorus; D000469:Alkaline Phosphatase
keywords: Alkaline phosphatase; DIP; DOP; Mediterranean Sea; Phosphorus; Plankton