Tetradecyltrimethylammonium degradation by Pseudomonas putida is more efficient in presence of Al3+

LIFFOURRENA, AS; SALVANO, MA; DOMENECH, CE; LUCCHESI, GI

Rosario, Santa Fé

Congreso; XLII Reunión Anual SAIB; 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Tetradecyltrimethylammonium degradation by Pseudomonas putida is more efficient in presence of Al3+. Liffourrena, Andrés S., Salvano, Mario A., Domenech, Carlos E. and Gloria I. Lucchesi, Dpto. Biología Molecular, FCEFQyN, UNRC, 5800-Río Cuarto, Argentina. E-mail: aliffourrena@yahoo.com Pseudomonas putida can use tetradecyltrimethylammonium (TDTMA) as sole C and N source. The trimethylamine (TMA) produced in the first degradation step by action of monooxygenase activity, was used as N source and also accumulated inside the cell, affecting the bacterial growth. Here, we report that Al3+ acted as a Lewis’ acid playing a role in the control of TMA intracellular through the reaction Al3+ + 2 :N(CH3)3 ® Al3+:[N(CH3)3]2, allowing the bacterial growth until total consumption of TDTMA. The intracellular TMA-Al3+ complex was determined quantitatively by the relationship between TMA intracellular (detected by GC-MS), total Al3+ incorporated (calculated by disappearance of culture media) and free-Al3+ intracellular (detected by fluorescence of Al3+-morin complex). Cells were growth in basal media with 50 mg l–1 TDTMA up stationary phase and Al3+ was added. In the presence of 0.1 mM Al3+, the free-TMA intracellular concentration decreased to zero with total consumption of TDTMA. With 0.005 mM Al3+ the low level of intracellular Al3+ was not sufficient to sequester the TMA and neither bacterial growth and TDTMA consumption was observed. In this case, the level of intracellular free-TMA was 1.30 10-9 nmol cell-1, sufficient for inhibit the monooxygenase activity. Thus, it is evident that the presence of Al3+ is a strategy for a more efficient utilization of TDTMA by P. putida.