Optimisation de la production de l’AIA par des rhizobactéries.

Abstract

Production of indole acetic acid (IAA) is an important trait of rhizospheric bacteria which stimulate and facilitate the growth of plants. The objective of this study is to improve the ability of the isolates of Stenotrophomonas maltophilia S1 and S2 to produce IAA by optimization of culture medium and conditions. The results reported an important production of IAA. The optimization of culture medium composition determinate that the most appropriate source of carbon and nitrogen for IAA production of the two isolates is malic acid and NH4Cl respectively. The effect of physical factors selected the acidity of pH = 6, the temperature at 30 ° C and the 6th days of incubation are the best culture conditions of IAA the production for the used bacteria. A maximum of bacterial growth was recorded after the 10th day of incubation for the bacterial isolate. In presence and absence of L-tryptophan in culture medium the isolates recorded an appreciable rate of IAA ranged from 2, 16 to 68, 95 μg / ml.