ISOLATION AND CHARACTERIZATION OF PLANT GROWTH-PROMOTING RHIZOBACTERIA PRODUCING INDOLE-3-ACETIC ACID FROM PLANTS GROWING IN EGYPT

El Khawas,, H. M.; Ibrahim, I. A.; Anwar, Hala M.; Hegazi, N. A.

doi:10.21608/jacb.2000.259828

ISOLATION AND CHARACTERIZATION OF PLANT GROWTH-PROMOTING RHIZOBACTERIA PRODUCING INDOLE-3-ACETIC ACID FROM PLANTS GROWING IN EGYPT

Document Type : Original Article

Authors

¹ Department of Microbiology, Faculty of Agriculture, Cairo University, Giza, Egypt.

² Tissue Culture Laboratory, Agriculture Development Systems Project, Ministry of Agriculture, Cairo, Egypt

³ Department of Microbiology, Faculty of Agriculture, Cairo University, Giza, Egypt

10.21608/jacb.2000.259828

Abstract

The present work aims to surveying plant growth-promoting rhizobacteria (PGPR) for their ability to produce the plant growth regulator indole-3-acetic acid (IAA). One hundred and forty eight isolates from such bacteria were obtained representing the rhizosphere and rhizoplane of maize, wheat, barley, sorghum and sugar cane form different locations in Egypt (Giza, Faioum, Kafer El-Sheikh and Ismailia). Twenty isolates were selected according to their ability to produce high amount of microbial IAA. The determination of IAA was carried out by calorimetric method and chromatographic analysis (GLC). These isolates were grown on minimal medium with different carbon sources. Glucose was the best carbon source for growing the most isolates and the presence of tryptophan was necessary for production of IAA. Seven isolates which produce IAA more than others were purified and identified applying both conventional morphological, cultural, biochemical methods and API microtube systems. Accordingly, they were placed under the species of Klebsieilla pneumomiae, Azospirillum spp. Enterobacter cloacae, and Pseudomonas fluorescens.