Identification of bacteria obtained from dactylorhiza urvilleana rhizoid region, metal tolerances, bioremidant characteristics and effects on maize germination in copper presence

Abstract

Rapidly increasing industrialization and technological developments cause hazardous wastes to spread to the environment at a high rate. In our study, three bacterial (5O1, 5O8, 112O1) strains isolated from the rhizoid region of the orchid plant (Dactylorhiza urvilleana) were characterized by conventional and molecular methods (nuclear 16S rDNA). In order to characterize the isolates, primarily macroscopic, microscopic, some biochemical and physical properties of the strains were investigated. The usability of the strains screened for their general properties as bioremediation strains, in the prevention of high copper accumulation in agricultural soils was investigated. With traditional and molecular studies, two of the strains were defined as species level (Bacillus mycoides, B. popilliae) and one at genus level. They were determined that strains were tolerant to the tested all metal salts (Fe, Zn, Cu, Pb and Ag salts in the 1- 10 mM range) except for the 5O1 strain to Ag salt, and 112O1 strain to Zn salt. The highest copper tolerance was observed in 5O1, 112O1 and 5O8 strains, respectively. The strains were determined that the copper minimum inhibition concentration values were 12.5-25 mM and the minimum bactericidal concentration value was 50 mM. The examined in terms of properties such as Indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) Deaminase activities, and phosphate solubility, it was determined that they promoted plant germination and growth. When the germination success of maize seeds in the presence of copper was examined, it was concluded that positive results were obtained, there was no significant difference between strains and therefore strains could be used in copper bioremediation.