MESORHIZOBIUM LOTI IMMOBILIZATION USING SOL – GEL PROCESS.

ALVAREZ GS, BERTINATTO JA, COPELLO GJ, DESIMONE MF, RUIZ OA AND DIAZ LE.

Pinamar. Buenos Aires . Argentina

Congreso; 10th Congress PABMB and XLI Reunión Anual SAIB; 2005

SAIB

Rhizobia are soil and rhizosphere bacteria of agronomic importance because they perform nitrogen-fixing symbioses with leguminous plants. The aim of this work was to generate an alternative way of inoculating Rhizobia in the fields and to obtain a higher number of living cells for a longer period of time in comparison with commercial formulas.  Two different matrices, silicon dioxide/hydrochloric acid and sodium silicate/citric acid, were used in the immobilization of these bacteria. Immobilized Rhizobium was preserved at 4º C for a period of a month. We observed the best results for the second matrix (sodium silicate/citric acid) suggesting that the presence of the organic acid plays a role in the protection of the bacteria. The number of bacteria falls from 108 to 107 CFU/ml due to the immobilization process itself, but then remains constant for a month. In the first matrix (silicon dioxide/hydrochloric acid) the number of initial cells falls from 108 to 106 CFU/ml but then also remains constant in the time. Other studies were performed to confirm that the immobilized Rhizobium were still able to nodulate plants, showing positive results. Rhizobia are soil and rhizosphere bacteria of agronomic importance because they perform nitrogen-fixing symbioses with leguminous plants. The aim of this work was to generate an alternative way of inoculating Rhizobia in the fields and to obtain a higher number of living cells for a longer period of time in comparison with commercial formulas.  Two different matrices, silicon dioxide/hydrochloric acid and sodium silicate/citric acid, were used in the immobilization of these bacteria. Immobilized Rhizobium was preserved at 4º C for a period of a month. We observed the best results for the second matrix (sodium silicate/citric acid) suggesting that the presence of the organic acid plays a role in the protection of the bacteria. The number of bacteria falls from 108 to 107 CFU/ml due to the immobilization process itself, but then remains constant for a month. In the first matrix (silicon dioxide/hydrochloric acid) the number of initial cells falls from 108 to 106 CFU/ml but then also remains constant in the time. Other studies were performed to confirm that the immobilized Rhizobium were still able to nodulate plants, showing positive results.