Fluorene and phenanthrene uptake by Pseudomonas putida ATCC 17514: Kinetics and physiological aspects

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Rodrigues, AC (Author) Other; Wuertz, S (Author) Other; Brito, AG (Author) Other; L. F. Melo (Author) FEUP

Journal

Title: Biotechnology and Bioengineering

Vol. 90 No. 3

Pages: 281-289

ISSN: 0006-3592

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 43 Citations

ISI Web of Science

Scopus - 45 Citations

COMPENDEX

Scientific classification

CORDIS: Technological sciences

Other information

Authenticus ID: P-000-3D0

DOI: 10.1002/bit.20377

Abstract (EN): Pseudomonas putida ATCC 17514 was used as a model strain to investigate the characteristics of bacterial growth in the presence of solid fluorene and phenanthrene. Despite the lower water-solubility of phenanthrene, P. putida degraded this polycyclic aromatic hydrocarbon (PAH) at a maximum observed rate of 1.4 +/- 0.1 mg L-1 h(-1), higher than the apparent degradation rate of fluorene, 0.8 +/- 0.07 mg L-1 h(-1). The role of physiological processes on the biodegradation of these PAHs was analyzed and two different uptake strategies were identified. Zeta potential measurements revealed that phenanthrene-grown cells were slightly more negatively charged (-57.5 +/- 4.7 mV) than fluorene-grown cells (-51.6 +/- 4.9 mV), but much more negatively charged than glucose-grown cells (-26.8 +/- 3.3 mV), suggesting that the PAH substrate induced modifications on the physical properties of bacterial surfaces. Furthermore, protein-to-exopolysaccharide ratios detected during bacterial growth on phenanthrene were typical of biofilms developed under physicochernical stress conditions, caused by the presence of sparingly water-soluble chemicals as the sole carbon and energy source for growth, the maximum value for TP/EPS during growth on phenanthrene (1.9) being lower than the one obtained with fluorene (5.5). Finally, confocal laser microscopy observations using a gfp-labeled derivative strain revealed that, in the presence of phenanthrene, P. putida::gfp cells formed a biofilm on accessible crystal surfaces, whereas in the presence of fluorene the strain grew randomly between the crystal clusters. The results showed that P. putida was able to overcome the lower aqueous solubility of phenanthrene by adhering to the solid PAH throughout the production of extracellular polymeric substances, thus promoting the availability and uptake of such a hydrophobic compound. (c) 2005 Wiley Periodicals, Inc.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9