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Gamal,Rawia F.; Abdelhady,Hemmat M.; Khodair,Taha A.; El-Tayeb,Tarek S.; Hassan,Enas A.; Aboutaleb,Khadiga A.. |
The present study aimed at developing a strategy to improve the volumetric production of PHAs by Pseudomonas fluorescens S48 using waste frying oil (WFO) as the sole carbon source. For this purpose, several cultivations were set up to steadily improve nutrients supply to attain high cell density and high biopolymer productivity. The production of PHAs was examined in a 14 L bioreactor as one-stage batch, two-stage batch, and high-cell-density fed-batch cultures. The highest value of polymer content in one-stage bioreactor was obtained after 60 h (33.7%). Whereas, the two-stage batch culture increased the polymer content to 50.1% after 54 h. High-cell-density (0.64 g/L) at continuous feeding rate 0.55 mL/l/h of WFO recorded the highest polymer content after... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pseudomonas fluorescens S48; Biopolymer; PHAs; Batch; Two-stage batch; High-celldensity fed batch; Bioreactor; Recovery. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000200034 |
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Simon-colin, Christelle; Raguenes, Gerard; Crassous, Philippe; Moppert, X; Guezennec, Jean. |
Pseudomonasguezennei biovar. tikehau was isolated from a microbial mat on the atoll of Tikehau in French Polynesia, and is able to synthesize medium chain length poly-beta-hydroxyalkanaote copolymers when grown on coprah oil. A two-step cultivation process was used and the biosynthesis of PHAs was followed along 52 h by regular culture sampling. The polyester was purified from freeze-dried cells and analysed by nuclear magnetic resonance (NMR), Fourier transform infra red (FTIR), and gas chromatography mass spectrometries. The copolyester produced by P. guezennei biovar. tikehau from coprah oil mainly consisted of saturated monomers, i.e. 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD), and the monomeric composition of the polyester did not change... |
Tipo: Text |
Palavras-chave: Polyhydroxyalkanaote; PHAs; Pseudomonas; "kopara"; Microbial mat. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6119.pdf |
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Morais,Gisele dos Santos; Pesenti,Emanuele Cristina; Cestari,Marta Margarete; Navarro-Silva,Mário Antônio. |
Phenanthrene, a Polycyclic Aromatic Hydrocarbon, remains adsorbed to sedimentary particles in aquatic environments. It affects mainly benthic organisms, and is considered potentially genotoxic. In ecotoxicology, species of Chironomus Meigen, 1803 are widely known as bioindicators of the effects of chemicals on aquatic organisms. This study investigates the effects of phenanthrene on the size of the head capsule of Chironomus sancticaroli Strixino & Strixino, 1981 larvae after chronic (eight days) exposure, and DNA damage after acute (96 hours) and chronic exposure (eight days), under laboratory conditions. DNA damage, evaluated using the alkaline comet assay, detected effects for both exposure periods, indicating that phenanthrene is toxic for C.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bioassay; Bioindicador; Development; DNA damage; PHAs. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702014000400003 |
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