The effects of incubation time, temperature, pH, and agitation on indole-3- acetic acid and gibberellic acid production in Aspergillus niger were studied. For indole-3-acetic acid production, 6 days of incubation at 25 °C and pH was found to be optimum. | Turk J Biol 34 (2010) 313-318 © TÜBİTAK doi: Indole-3-acetic acid and gibberellic acid production in Aspergillus niger Işıl SEYİS BİLKAY1,*, Şafak KARAKOÇ2, Nilüfer AKSÖZ1 1 Hacettepe University, Faculty of Science, Department of Biology (Biotechnology), 06532 Beytepe, Ankara - TURKEY 2 MARA, National Food Reference Laboratory, Department of Biotechnology and GMO, Yenimahalle, 06171, Ankara - TURKEY Received: Abstract: The effects of incubation time, temperature, pH, and agitation on indole-3- acetic acid and gibberellic acid production in Aspergillus niger were studied. For indole-3-acetic acid production, 6 days of incubation at 25 °C and pH was found to be optimum. Optimum conditions for gibberellic acid production were 12 days of incubation at 30 °C and pH . Agitation increased both indole-3-acetic acid and gibberellic acid production. Key words: Aspergillus niger, gibberellic acid, indole-3-acetic acid, phytohormone, plant growth regulator Aspergillus niger’den indol asetik asit ve gibberellik asit üretimi Özet: İnkübasyon süresi, sıcaklık, pH ve çalkalamanın, Aspergillus niger’den indol-3-asetik asit ve gibberellik asit üretimine etkisi araştırıldı. İndol asetik asit üretimi için 6 gün inkübasyon süresi, 25 °C sıcaklık ve pH 6,0 uygunken, gibberellik asit üretimi için 30 °C, pH 5,0 ve 12 gün inkübasyon süresinin uygun olduğu saptandı. Çalkalamanın ise hem indol-3-asetik asit hem de gibberellik asit üretimini arttırdığı gözlendi. Anahtar sözcükler: Aspergillus niger, gibberellik asit, indol-3-asetik asit, bitki hormonu, bitki büyüme düzenleyicisi Introduction Gibberellic acid is a plant growth regulator of economic and industrial importance (1). Phytohormones, mainly including auxins, cytokinins, abscisic acid, gibberellins, and ethylene, induce some important physiological responses at different stages of plant development at low concentrations (2). Various gibberellins are available and are associated with several
