ISOLATION AND ACTIVITY OF NITRIFYING BACTERIA IN INCREASING THE VIABILITY OF SOIL NITROGEN

Abstract

Nitrogen is essential nutrient for the growth of organisms and become a limiting factor in soils. Nitrifying bacteria consist of ammonifying and nitrifying bacteria. The former oxidize ammonia into nitrite and the later oxidize nitrite into nitrate. A number of nitrifying bacteria has been isolated from a pond sediment using media of Nitrosomonas medium and Nitrobacter medium by pour plate method. A total of 7 isolates nitrifying bacteria were found from pond sediment. Two isolates were Gram negative and 5 isolates were Gram positive. The population number of the Gram-negative bacteria was 3 x 103 cfu.mL-1, while the Gram-positive bacteria were ranging from 2.0 x 103 to 5.0 104 cfu.mL-1. The nitrifying bacterial isolates were capable of reducing ammonia concentration in the amount of 0.878-10,261 ppm, increasing nitrite concentration ranging from 0.313-1.358 ppm, and increasing nitrate concentration in the amount of 0.215-0.262 ppm.