%0 Conference Paper %B Internatiomal Symposium on Indonesian Biodiversity %D 2013 %T Screening of Nitrogen Fixer from Rhizospheric Bacteria Isolates with High Ammonium Excretion Ability %A Oslan Jumadi %A Hartono Hartono %A Liawati Liawati %K ammonium excretion %K nitrogen fixer %K rhizospher bacteria %X The aims of study is to determine the characteristics of nitrogen fixer from rhizospheric bacteria which was isolated from rhizosphers of maize (Zea mays L.) and rice (Oryza sativa) in Takalar district of South Sulawesi. The studies were consisted isolation of nitrogen fixing bacteria by using nitrogen free media of Ashby and Burk. Characterization of bacteria isolates which potentially have high ammonium excretion have done by catalase, gelatin, nitrate reduction, starch hydrolysis, casein hydrolysis, methyl red, and gram staining methods. We have isolated twenty of nitrogen fixing bacteria growth on nitrogen free medium, however among the isolates only six isolates have high capability to release ammonium which detected by nessler reagent, namely ATP1.4; ATJ2.4.6; BTJ1.1.1; BTJ2.2.1; BTJ2.2, and BTP1.2.2 with an average of ammonium release were 95 g/L, 5.0 g/L, 315 g/L, 256 g/L, 192 g/L, and 261 g/L, respectively. The six isolates have different physiological characteristics in the ability to reduce nitrate, cell wall appearance (gram staining), methyl red, catalase reaction, and the ability of the hydrolysis of starch and gelatin %B Internatiomal Symposium on Indonesian Biodiversity %I Faculty of Biology, Jenderal Soedirman University %C Purwokerto, Central Java, Indonesia %G eng