Dados do Trabalho

Título

POTASSIUM SOLUBILIZATION OF ROCK POWDERS BY BACILLUS SPP.

Resumo

Rock powder is a mining residue that can be used as a chemical, physical and biological soil conditioner. The slow release of nutrients is a limitation for the use of rock powders. The interactions of microorganisms with these materials promote the biosolubilization of important nutrients for cultures. Based on this, we aimed to evaluate the potassium (K) solubilization of rock powders from the activity of Bacillus subtilis and Bacillus pumilus. For this, falcons received 45 mL of modified Aleksandrov medium and supplemented with 3g L-1 of rock powder as the only source of K. The pH was adjusted to 7.0 and each treatment received a colony of the respective isolate. Thus, 9 treatments (3 rock powders and 3 isolates; 2 Bacillus spp. and 1 Bacillus spp. free control) and 5 replications were established. After 12 days under agitation at 120 rpm and a temperature of 28°C, the tubes were centrifuged at 7,000 g for 11 minutes to separate the supernatant. Afterwards, the supernatant was filtered through no 42 paper and the K concentration was determined by flame spectrophotometry. The means were compared by Tukey's test at 5% probability in the Sisvar 5.6 program. B. subtilis showed greater potential for biosolubilization in the three types of rock. In granite, B. subtilis showed an average (5.08 mg L-1) statistically higher than B. pumillus (4.82 mg L-1) and the control (4.44 mg L-1). In diabase B. subtilis (1.02 mg L-1) and B. pumillus (0.96 mg L-1) did not differ among themselves, but did differ from the control (0.78 mg L-1). In phonolite, B. pumilus (1.98 mg L-1) and the control (1.30 mg L-1) did not differ from each other, but showed statistically lower means than B. subtilis (5.58 mg L-1). These results suggest that B. subtilis has the potential as a K biosolubilizer for granite, diabase and phonolite.

Palavras-chave

Microbial activity; Bioprospecting; Biotechnology

Instituição financiadora

CAPES