Untersuchungen zum Abbau von Benzoesäure durch ein Gram-negatives Bakterium unter Denitrifikationsbedingungen
Untersuchungen zum Abbau von Benzoesäure durch ein Gram-negatives Bakterium unter Denitrifikationsbedingungen
Microbial degradation of aromatic compounds, especially benzoic acid, was investigated in batch and continuous cultures under denitrifying conditions. A bacterium which was able to use benzoic acid as sole source of carbon and energy under denitrifying conditions was isolated during a one year perio...
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Personal Name(s): | Raphael, T. (Corresponding author) |
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Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Kernforschungsanlage Jülich, Verlag
1989
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Physical Description: |
XI, 131 p. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Berichte der Kernforschungsanlage Jülich
2322 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Microbial degradation of aromatic compounds, especially benzoic acid, was investigated in batch and continuous cultures under denitrifying conditions. A bacterium which was able to use benzoic acid as sole source of carbon and energy under denitrifying conditions was isolated during a one year period from sewage sludge. Thestrain was a gram-negative aerobic very short with similarity to the genus M oraxella. It was found that the growth rate of this strain in a denitrifying batch-culture is dependant on the method of preculturing. Inoculation of batch-cultures with bacteria from continuous cultures did not give reproducible growth rates. At present there are no explanations for this phenomenon. In batch-cultures 4 rnmoles of benzoic acid were degraded under reduction of 20 mmoles of nitrate. Nitrite as an intermediate product was detected in concentrations up to 17 mmoles/l. Degradation of $^{14}$C ring-labeled benzoic acid under strict anoxic conditions in batch culture resulted in the following distribution of radioactivity: - 33,5 % as CO$_{2}$, - 34,5 %, in bacterial dry mass and - 31,1 % in the remaining mineral medium.Maximum growth rate in batch culture was estimated at 0,1/h with variable concentrations of nitrite as intermediate. In continuous cultures no nitrite was detectableunder nitrate-limitation but nitrite accumulated inhibition of groth could be observed under limitation of benzoic acid as carbon and energy source. Maximum growth rate in nitrate-limited continuous culture was 0,17/h and 0,08/h in benzoic acid limited culture. The saturation constant for nitrate was determined as 5 $\mu$mol and for benzoic acid 0,15 mmol. Under different conditions of culture instability a likely intermediate of benzoic acid degradation could be detected. The structure based on GC/MS studies was proposed as 2,4 heptadienedicarboxylicacid. This compound was also found in aerobic cultures. A biotechnical utilization of anoxic degradation of aromatic substances could be useful with this or other strains because of the relatively fast growth rates achieved. |