Yüzüncü Yıl Üniversitesi Ziraat Fakültesi Tarım Bilimleri Dergisi, vol.34, no.3, pp.409-419, 2024 (Peer-Reviewed Journal)
Endophyte bacteria are
microorganisms that pass all or part of their life cycle in the tissues of
healthy plants without causing any obvious signs of disease. Most
siderophore-producing endophytic bacteria could improve the plant growth. Here,
the effect of metals, iron (Fe), nickel (Ni), and cobalt (Co), on the growth
and siderophore production profiles of 30
endophyte bacterial isolates were investigated. The results of the Minimum Inhibition Concentration
(MIC) tests showed that endophytes exhibit varying degrees of tolerance to
heavy metals and the metal tolerance decreased in the order Fe3+>Ni2+>Co2+.
It was revealed that while 10 isolates could not produce siderophores under any
circumstances, 20 isolates produced siderophores at different degrees, and
siderophore molecules synthesized and secreted by these 20 isolates had
affinities for all three metals (Fe3+, Co2+, and Ni2+).
In addition, siderophore production profiles of isolates under each heavy metal
stress were investigated by adding these metals to the Chromium Azurol
Sulfonate (CAS) medium at optimum concentration. The results suggested that
siderophore synthesis could be one of the coping mechanisms of only two
isolates with Co2+ and Ni2+ heavy metals. In the final stage of the study, molecular
identification of a certain number of isolates selected according to their
siderophore production values was carried out by 16S rRNA sequencing. As a
result of the sequence analysis, 2 Pseudomonas sp., 4 Bacillus
sp., 1 Chryseobacterium sp., 1 Staphylococcus sp., and 1 Peribacillus
sp. were revealed.