Isolasi dan Karakterisasi Bakteri Penghasil Indole-3-Acetic Acid (IAA) yang Berasal dari Area Penambangan Batu Kapur.

Abstract

Soil degradation due to limestone activity can be overcome by planty plant reclamation. The growth of seedling plants reclamation can be induced to grow well on nutrient-poor and alkaline soil condition by using the indigenous bacteria, such as IAA producing bacteria. The research was aimed to isolate and characterize Indole-3-acetic acid (IAA) producing bacteria from limestone quarry. Isolation was performed on 13 soil samples of limestone quarry, and then 25 isolates were obtained. The selection by hypersensitive test showed 2 isolates used to test further, namely isolate QC 5C32 and QC 7B41. Both isolates were identified by KIT API 50 CH, a series of biochemistry reaction had 99.9% similarity with Bacillus megaterium, had rod-shapes, Gram positive, and produced endospore. The highest IAA production occured by adding 1.5 mM of Ltryptophan. The result showed that amount of IAA was 10.345 ppm (QC 5C32) and 18.723 ppm (QC 7B41). Application of both isolates toward siratro (Macroptilium atropurpureum) showed impact to the growth of primary root, number of lateral root, and fresh weight of siratro root sprout.