Twelve endophytic bacteria were isolated from
the meristem of in vitro Cymbidium eburneum orchid,
and screened according to indole yield quantified by
colorimetric assay, in vitro phosphate solubilization, and
potential for plant growth promotion under greenhouse
conditions. Eight strains with positive results were classified
into the genus Paenibacillus by FAME profile,
and evaluated for their ability to increase survival and
promote the growth of in vitro germinated Cattleya loddigesii
seedlings during the acclimatization process. The
obtained results showed that all strains produced detectable
indole levels and did not exhibit potential for solubilizing
inorganic phosphate. Particularly, an increase of the total
biomass and number of leaves was observed. Two strains of
Paenibacillus macerans promoted plant growth under greenhouse
conditions. None of the treatments had a deleterious
effect on growth of inoculated plants. These results suggest
that these bacterial effects could be potentially useful to
promote plant growth during seedling acclimatization in
orchid species other than the species of origin.