The bacteria in the sediment of the Sahela reservoir (Morocco): potential impacts on phosphorus budget.
Temporal variations of phosphorus concentrations, bacterial abundance and activity of fractionated (i.e: size fractions: 0.22 to 0.65 microm; 0.65 to 100 microm and 0.22 to 100 microm) alkaline phosphatase (APA) were studied in situ in a benthic chamber placed in a station near urban inputs in the Sahela reservoir (Morocco) on September and October 98. Results show that low oxygen concentrations induced enhanced concentrations of orthophosphates, and bacterial numbers and APA activity reached their highest values. Anoxic conditions and the decrease of pH favour the dissolution of particulate phosphorus and the release of soluble reactive phosphorus. This release is accompanied simultaneously by an increase in the abundance of anaerobic bacteria and a progressive reduction in APA. Lastly, the release of phosphorus together with urban inputs from the city of Taounate should be considered as potential inducers of the eutrophication of the reservoir.
Mhamdi
B Alaoui
BA
Université Sidi Mohamed Ben Abdallah, Faculté des Sciences, Département de Biologie, B. P. 1796, Fès-Atlas, Morocco.
Azzouzi
A
A
Khattabi
H
H
Mhamdi
M Alaoui
MA
Aleya
L
L
D000469:Alkaline Phosphatase / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology / Q000254:growth & development* / Q000302:isolation & purification; D015169:Colony Count, Microbial; D005618:Fresh Water / Q000382:microbiology*; D019015:Geologic Sediments / Q000382:microbiology*; D009018:Morocco; D010758:Phosphorus / Q000378:metabolism*; D014881:Water Supply
D010758:Phosphorus; D000469:Alkaline Phosphatase