HR: 11:05h
AN: B11E-04    [PDF]
TI: Fluorapatite as Inorganic Phosphate Source for the Cyanobacterium Anabaena PCC 7120
AU: Schaperdoth, I
EM: ius2@psu.edu
AF: Department of Geosciences, 503 Deike Bldg. The Pennsylvania State University, University Park, PA 16802 United States
AU: * Brantley, S
EM: brantley@essc.psu.edu
AF: Department of Geosciences, 503 Deike Bldg. The Pennsylvania State University, University Park, PA 16802 United States
AB: We investigated the hypothesis that the cyanobacterium Anabaena PCC 7120 is able to use fluorapatite (FAP) as sole phosphate source for growth. In the experimental setup the dissolution of FAP was tested in a phosphate free growth medium in the presence and absence of the Anabaena, as well as the cell free supernatant of an Anabaena culture. The results were compared with that of an Anabaena culture grown without fluorapatite. Parameters measured were pH, dissolved P and Ca, as well as cell density. The FAP grains were analyzed using SEM and XPS. Additionally, the differential expression of secreted proteins in cultures with and without dissolved phosphate was examined. P-limited Anabaena cultures tend to aggregate and in the presence of FAP the cells attached themselves to the mineral grains. The cultures benefit from the presence of FAP. The cells have a very effective P-uptake system that is able to take up dissolved phosphate very efficiently and draw the concentrations down to very low levels. Furthermore, the SEM analysis of FAP showed an etching of the mineral grains in the samples from the Anabaena cultures. The mechanism of apatite dissolution with and without Anabaena will be discussed in terms of these experimental observations.
DE: 0330 Geochemical cycles
DE: 0399 General or miscellaneous
DE: 0400 Biogeosciences
DE: 1099 General or miscellaneous
SC: Biogeosciences [B]
MN: 2003 Fall Meeting