ISSN:
0138-4988
Keywords:
Life Sciences
;
Life Sciences (general)
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Process Engineering, Biotechnology, Nutrition Technology
Notes:
A 4-nitrophenol degrading strain PNP1 isolated from the El-Harrach River near Algiers (Algeria) was studied with respect to its growth behaviour. According to the morphological and biochemical characteristics this strain was assigned to Pseudomonas putida. Besides 4-nitrophenol, the strain also used 1,2- and 1,4-dihydroxybenzene, benzoate, 4-hydroxybenzoate and 3,4-dihydroxybenzoate as sources of carbon and energy, degrading them exclusively via the ortho pathway. Pseudomonas putida PNP1 degrades 4-nitrophenol through a purely oxidative pathway with release of the nitro group as nitrite. During cultivation with 4-nitrophenol in ammonium-containing mineral medium, the strain PNP1 grew optimally at pH 7 and at a temperature between 30 and 35°C and showed stoichiometric nitrite release (at pH 7 and 30°C MONOD model parameters μmax = 0.615 h-1 and KS = 0.145 mg/l). A phenomenological model for the description of growth inhibition at high 4-nitrophenol concentrations was derived (below 400 mg/l only weak inhibition and at 600 mg/l acute toxicity). In ammonium-free medium, the maximum specific growth rate was reduced to 0.318 h-1 and part of the 4-nitrophenol-N was used as the nitrogen source (32% N in biomass and 68% N in nitrite). The yield coefficients of strain PNP1 were smaller in ammonium-free than in ammonium-containing medium (e.g. with 4-nitrophenol YX/S = 0.305 g/g compared to 0.350 g/g), which can be explained by the energy expense for the assimilatory nitrite reduction in the biosynthesis of N-containing cellular compounds. But the oxygen consumption was only slightly influenced by the ammonium content of the cultivation medium (e.g. with 4-nitrophenol YO/S = 1.005 g/g compared to 0.954 g/g).
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/abio.370180105
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