| Full text | |
| Author(s): |
Pereira, Erica Mendes
[1, 2]
;
Silva-Queiroz, Sonia Regina
[1, 2]
;
Cabrera Gomez, Jose Gregorio
[1, 2]
;
Ferreira Silva, Luiziana
[1, 2]
Total Authors: 4
|
| Affiliation: | [1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, BR-05508000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Programa Posgrad Interunidades Biotecnol, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Canadian Journal of Microbiology; v. 55, n. 6, p. 688-697, JUN 2009. |
| Web of Science Citations: | 2 |
| Abstract | |
The objective of the present work was to evaluate the relevance of the 2-methylcitric acid cycle (2MCC) to the catabolism of propionate in Burkholderia sacchari. Two B. sacchari mutants unable to grow on propionate were obtained: one disrupted in acnM, and the other in acnM and prpC deleted. An operative 2MCC significantly reduces the bacterial ability to incorporate 3-hydroxyvalerate (3HV) into a biodegradable copolyester accumulated from carbohydrates plus propionate. The efficiency of the mutants in converting propionate to 3HV units (Y(3HV/prp)) increased from 0.09 g.g(-1) to 0.81-0.96 g.g(-1), indicating that acnM and prpC are both essential for growth on propionate. None of the mutations resulted in achievement of the maximum theoretical Y(3HV/prp) (1.35 g.g(-1)). When increasing concentrations of propionate were supplied, decreasing values of Y(3HV/prp) were observed. The results obtained corroborate the hypothesis of the presence of other propionate catabolic pathways in B. sacchari. The 2MCC would be the more operative pathway, but a second pathway, which remains to be elucidated, would assume more importance under propionate concentrations of 1 g.L(-1) or higher. The efficiency in converting propionate to 3HV units can be improved by decreasing the propionate concentrations, owing to the role of the 2MCC. (AU) | |