Isolasi dan Uji Kemampuan Bakteri Endofit Diazotrof yang Memfiksasi Nitrogen Bebas pada Akar Kelapa Sawit (Elaeis guineensis Jaqc.)

Abstract

A study on isolation and assay of diazotrophic endophytic bacterial isolates from palm oil root has been done in Laboratory of Microbiology and green house of Department of Biology, Faculty of Mathematics and Natural Sciences, University of Sumatera Utara. The aim of the study was to know diazotrophic bacteria isolated from palm oil root and their role in palm oil growth. Twenty bacterial isolates were successfully isolated, and were morphologically and biochemically characterized. Some isolates shared the same characteristics i.e. NFB 2, NFB 14 and NFB 16, NFB 11, NFB 12 and NFB 19, and NFB 15 and NFB 20. Assay on nitrogen fixation of all isolates showed that NFB 2, NFB 3 and NFB 4 fixed nitrogen more than others which were shown by ARA activities of 2.10, 2.78 and 3.13 ppm/h, respectively. There was a correlation between the ability to fix nitrogen with plant height, number of leaves, and number of roots.