Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/44156
Title: Enhanced polyhydroxyalkanoates accumulation by Halomonas spp. in artificial biofilms of alginate beads.
Author: Berlanga Herranz, Mercedes
Miñana i Galbis, David
Domènech Cabrera, Òscar
Guerrero, Ricardo, 1943-
Keywords: Polisacàrids
Bacteris
Cèl·lules
Biopolímers
Biofilms
Polysaccharides
Bacteria
Cells
Biopolymers
Biofilms
Issue Date: Dec-2012
Publisher: Spanish Society for Microbiology (SEM) and Viguera Editores SL
Abstract: Microbial mats are complex but stable, multi-layered and multi-functional biofilms, which are the most frequent bacterial formations in nature. The functional strategies and physiological versatility of the bacterial populations growing in microbial mats allow bacteria to resist changing conditions within their environment. One of these strategies is the accumulation of carbon- and energy-rich polymers that permit the recovery of metabolic activities when favorable conditions are restored. In the present study, we systematically screened microbial mats for bacteria able to accumulate large amounts of the ester carbon polymers polyhydroxyalkanoates (PHA). Several of these strains were isolated from Ebro Delta microbial mats and their ability to accumulate PHA up to 40-60 % of their dry weight was confirmed. According to two identification approaches (16S rRNA and ropD genes), these strains were identified as Halomonas alkaliphila (MAT-7, -13, -16), H. neptunia (MAT-17), and H. venusta (MAT-28). To determine the mode of growth yielding maximum PHA accumulation, these three different species were cultured in an artificial biofilm in which the cells were immobilized on alginate beads. PHA accumulation by cells that had detached from the biofilm was compared with that of their planktonic counterparts. Experiments in different culture media showed that PHA accumulation, measured as the relative fluorescence intensity after 48 h of incubation at 30 °C, was higher in immobilized than in planktonic cells, with the exception of cells growing in 5 % NaCl, in which PHA accumulation was drastically lower in both. Therefore, for obtaining high PHA concentrations, the use of immobilized cells may be a good alternative to the PHA accumulation by bacteria growing in the classical, planktonic mode. From the ecological point of view, increased PHA accumulation in detached cells from biofilms would be a natural strategy to improve bacterial dispersion capacity and, consequently, to increase survival in stressed environments.
Note: Reproducció del document publicat a: http://dx.doi.org/10.2436/20.1501.01.172
It is part of: International Microbiology, 2012, vol. 15, num. 4, p. 191-199
Related resource: http://dx.doi.org/10.2436/20.1501.01.172
URI: http://hdl.handle.net/2445/44156
ISSN: 1139-6709
Appears in Collections:Articles publicats en revistes (Farmàcia, Tecnologia Farmacèutica i Fisicoquímica)
Articles publicats en revistes (Genètica, Microbiologia i Estadística)
Articles publicats en revistes (Biologia, Sanitat i Medi Ambient)

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