title: Monitoring intracellular polyphosphate accumulation in enhanced biological phosphorus removal systems by quantitative image analysis.
abstract: A rapid methodology for intracellular storage polyphosphate (poly-P) identification and monitoring in enhanced biological phosphorus removal (EBPR) systems is proposed based on quantitative image analysis (QIA). In EBPR systems, 4',6-diamidino-2-phenylindole (DAPI) is usually combined with fluorescence in situ hybridization to evaluate the microbial community. The proposed monitoring technique is based on a QIA procedure specifically developed for determining poly-P inclusions within a biomass suspension using solely DAPI by epifluorescence microscopy. Due to contradictory literature regarding DAPI concentrations used for poly-P detection, the present work assessed the optimal DAPI concentration for samples acquired at the end of the EBPR aerobic stage when the accumulation occurred. Digital images were then acquired and processed by means of image processing and analysis. A correlation was found between average poly-P intensity values and the analytical determination. The proposed methodology can be seen as a promising alternative procedure for quantifying intracellular poly-P accumulation in a faster and less labour-intensive way.
authors.affiliation: CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal E-mail: ecferreira@deb.uminho.pt.
authors.forename: Daniela P
authors.initials: DP
authors.lastname: Mesquita
authors.affiliation: CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal E-mail: ecferreira@deb.uminho.pt; Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra, Portugal.
authors.forename: A Luís
authors.initials: AL
authors.lastname: Amaral
authors.affiliation: CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal E-mail: ecferreira@deb.uminho.pt; Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra, Portugal.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Leal
authors.affiliation: CQFB/REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Mónica
authors.initials: M
authors.lastname: Carvalheira
authors.affiliation: CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal E-mail: ecferreira@deb.uminho.pt.
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Cunha
authors.affiliation: CQFB/REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Adrian
authors.initials: A
authors.lastname: Oehmen
authors.affiliation: CQFB/REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Maria A M
authors.initials: MA
authors.lastname: Reis
authors.affiliation: CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal E-mail: ecferreira@deb.uminho.pt.
authors.forename: Eugénio C
authors.initials: EC
authors.lastname: Ferreira
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D010758:Phosphorus / Q000737:chemistry*; D011122:Polyphosphates / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011122:Polyphosphates; D010758:Phosphorus