Title |
Analysis of the Abilities of Endophytic Bacteria Associated with Banana Tree Roots to Promote Plant Growth |
Author |
Leandro Fernandes Andrade, Gleika Larisse Oliveira Dorasio de Souza, Silvia Nietsche, Adelica Aparecida Xavier, Marcia Regina Costa, Acleide Maria Santos Cardoso, Marlon Cristian Toledo Pereira, and Débora Francine Gomes Silva Pereira |
Address |
Laboratório de Biotecnologia, Departamento de Ciências Agrárias, Universidade Estadual de Montes Claros, Avenida Reinaldo Viana 2630, Caixa Postal 91, CEP 39440-000, Janaúba, Minas Gerais, Brazil |
Bibliography |
Journal of Microbiology, 52(1),27–34, 2014,
|
DOI |
10.1007/s12275-014-3019-2
|
Key Words |
Musa spp. nitrogen fixation, indole-3-acetic acid, phosphate solubilization, Bacillus sp. |
Abstract |
A total of 40 endophytic bacterial isolates obtained from banana
tree roots were characterized for their biotechnological
potential for promoting banana tree growth. All isolates
had at least one positive feature. Twenty isolates were likely
diazotrophs and formed pellicles in nitrogen-free culture
medium, and 67% of these isolates belonged to the genus
Bacillus sp. The isolates EB-04, EB-169, EB-64, and EB-144
had N fixation abilities as measured by the Kjeldahl method
and by an acetylene reduction activity assay. Among the 40
isolates, 37.5% were capable of solubilizing inorganic phosphate
and the isolates EB-47 and EB-64 showed the highest
solubilization capacity. The isolate EB-53 (Lysinibacillus sp.)
had a high solubilization index, whereas 73% of the isolates
had low solubilization indices. The synthesis of indole-3-
acetic acid (IAA) in the presence of L-tryptophan was detected
in 40% of the isolates. The isolate EB-40 (Bacillus sp.)
produced the highest amount of IAA (47.88 μg/ml) in medium
supplemented with L-tryptophan and was able to synthesize
IAA in the absence of L-tryptophan. The isolates
EB-126 (Bacillus subtilis) and EB-47 (Bacillus sp.) were able
to simultaneously fix nitrogen, solubilize phosphate and produce
IAA in vitro. The results of this study demonstrated
that the isolates analyzed here had diverse abilities and all
have the potential to be used as growth-promoting microbial
inoculants for banana trees. |