Isolation of Diazotrophic Endophyte Bacteria from Sugarcane and Bacterial Characterization using Phenotypic Approach

Wiwik E. Widayati

Pusat Penelitian Perkebunan Gula Indonesia, Jl. Pahlawan 25 Pasuruan

Abstract

Isolation and characterization bacteria are the unity steps in microbiology methods. Those steps are usefull to simplify the bacteria diversity which were isolated in this research for further observations. The aim of this study was to isolate diazotrophic endophyte bacteria from sugarcane and to characterize bacteria obtained by using phenotypic properties. The diazotrophic endophyte bacteria were isolated by using selective isolation, while their diazotrophic properties were determined with nitrogenase activity (ARA). Similarities among bacteria were then figured out as a dendogram by using phenotypic and chemosystematic characters. The results showed that 12 isolates of bacteria endophyte were successfully isolated and 7 isolates of them were identified as diazotrophic bacteria. Congruence of the results was obtained from phenotypic characterization including morphology, biochemical characters and cellular protein profile. The data showed that 4 isolates (10.2.2; 10.2.3; 10.3.2.1 and 10.3.2.2) were strongly indicated from the same genus, because those isolates located at ≥ 96% of index similarity. These isolates were also indicated different from other isolates (10 K1, 10 K2 and NB12). Numerical systematic used in this research was useful for selecting the bacteria isolates that will be used for further steps of the research.

Key words : diazotrophic bacteria, endophyte, sugarcane, phenotyphic dan numerical systematic