Caracterização de cepas de bacillus thuringiensis e seus efeitos na promoção do crescimento de tomateiro (Solanum Lycopersicum Micro-Tom)

Abstract

With population growth and increasing environmental concerns, sustainable agricultural practices have become increasingly relevant. This study evaluated the potential of 13 strains of Bacillus thuringiensis (Bt), obtained from the Central Laboratory of Molecular Biology (LCBM) at the Federal University of Lavras (UFLA), in promoting plant growth through the production of indole-3-acetic acid (IAA), seed priming, and enzymatic activities. The analysis focused on the strains’ ability to synthesize IAA, their effect on the germination of Solanum lycopersicum cv. Micro-Tom seeds, and their enzymatic activities (proteolytic, amylolytic, cellulolytic, lipolytic, and phosphate solubilization). IAA production was determined by colorimetry; seed priming was conducted in a completely randomized design with three replicates; and enzymatic activities were assessed by halo formation on selective media. Statistical analysis included ANOVA and mean comparisons using Scott-Knott and Tukey tests (p ≤ 0.05). The results showed that some Bt strains produced high levels of IAA, promoted seed germination, and expressed distinct enzymatic activities, with emphasis on proteolytic activity. These findings suggest that certain Bt strains have potential as sustainable agricultural biostimulants.