ISOLATION OF THE BACTERIA STRAINS HAVING THE CAPABLE OF PRODUCING INDOLE-3-ACETIC ACID (IAA) FROM PLANT SOIL NGOC LINH GINSENG IN KIM NOI, MU CANG CHAI, YEN BAI

Abstract

Indole-3-acetic acids are phytohormones belonging to the auxins. IAA has produced groups of microorganisms living in the rhizosphere bacteria root, such as Pseudomonas, Azospirillum, Azotobacter, Klebsiella, Enterobacter, Alcaligenes, Athobacter, Bacillus, and Serratia. From 4 samples of plant soil Ngoc Linh ginseng with an age of 1-2 years and isolated 14 bacteria strains capable of producing IAA, three strains with symbols YB26, YB38, and YBD2B7 are capable of producing IAA >20ug/ml. Study on biological characteristics of 03 strains with the results: good growth on carbon sources such as D-glucose and D mannitol; temperature 20-300C, pH 5 to 9, and 3 strains are able to produce extracellular enzymes such as amylase, cellulase, and protease. Classifying 02 strains based on 16S rRNA gene sequences, two strains, YB26 and YB38 have high similarity (>99%) with genes of strains of Bacillus. The fermentation fluid test of 02 strains increased the germination of seed vegetables by 4-9%.