KKU Research Journal
ISSN 0859-3957

շ 19 Ѻ 6+ January - February 2015

Optimization of indole-3-acetic acid (IAA) production by rhizobacteria isolated from epiphytic orchids

Kajohnpong Dasri*, Jureeporn Kaewharn, Sungwan Kanso and Suphavee Sangchanjiradet


Microbiology Program, Faculty of Science, Ubon Ratchathani Rajabhat University

Department of Biological Science, Faculty of Science, Ubonrajathanee University

Biology Program, Faculty of Science, Ubon Ratchathani Rajabhat University

*Correspondent author: john_ubu@hotmail.com



The optimal conditions for indole-3-acetic acid (IAA) production by bacterial isolate DPY-05 (Gram-positive, rods), living in association with aerial orchid roots (Dendrobium pulchellum) were studied. The factors that affect the IAA production were investigated including culture media, pH, temperature, agitation and culture period. The results showed that the isolated DPY-05 gave the highest amount of IAA of 67.18 ?g/ml when cultured in King-B medium supplemented with tryptophan 2.5 mM (KB+Trp) pH 7.0 at 37oC in static condition for 6 days.


Keywords : Optimization, Indole-3-acetic acid, Orchid rhizosphere, Plant-growth promoting rhizobacteria


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