ISOLATION AND IDENTIFICATION OF RHIZOBACTERIA IN MARSILEA CRENATA PRESL. EXPOSED TO LINEAR ALKYLBENZENE SULFONATE DETERGENTFida Rachmadiarti, Mahanani tri Asri, Ahmad Bashri, Yuliani and Farah Aisyah NafidiastriAbstract Water clover (Marsilea crenata Presl.) is a plant able to grow well in wetlands contaminated with Linear Alkylbenzene Sulfonate (LAS) detergent. The ability M. crenata to absorb this detergent was found to be often assisted by bacteria at the root through phytoremediation process. The aim of the study was to isolate and identify bacteria in the roots of M. crenata exposed to LAS detergent. Samples of M. crenata roots exposed to 20 ppm LAS detergent were taken, lysed, and homogenized. After that, dilution was performed on the homogenate, before it was grown on NA medium. The different isolates that were grown were purified in a test tube containing NA medium to obtain pure isolates. Each isolate was identified based on macroscopic and microscopic characteristics in addition to physiological characteristics through biochemical tests using the Microbact Identification System Kit. Content of LAS in plant media were analyzed using spectrophotometry. Morphology results were identified using Bergeyâs Manual of Determinative Bacteriology. The data obtained were analyzed descriptively qualitatively. Decreasing in LAS content after 10 days of treatment was found in the plant, while results of bacteria identification obtained four species of rhizosphere microbes found in the roots that previously known to have a role in LAS phytoremediation; Bacillus myocides (similarity coefficient of 80%), Actinomyces odontolyticus (90%), Bacillus pantothenticus (70%), and Actinomyces viscosus (90%). |