Isolasi dan seleksi bakteri penitrifikasi dari sampel tanah di sekitar kandang ternak di kabupaten Bogor

Abstract

Wastewater such as domestic waste and industrial waste, in generally are dump into the waterbody such as river and lake. These wastewater may contain ammonium (NH4 +). Ammonium is nitrogenous compounds that can be toxic at high concentration. One of many methods that can solve the accumulation of ammonium, is the method of nitrification process. Nitrification of ammonium may lower than concetration of ammonium in waste water. This process using of nitrifying bacterial activity. The nitrifying bacteria that commonly reported are Nitrosomonas sp. and Nitrobacter sp. Nitrosomonas sp. are type of bacteria that can oxidize ammonium to nitrite, and Nitrobacter sp. are type of bacteria that can oxidize nitrite to nitrate. The objectives of this research were to isolate ammonium oxidizing bacteria (Nitrosomonas sp.) and nitrite oxidizing bacteria (Nitrobacter sp.), also to evaluate the ability of these bacterial in reducing the ammonium and increased the nitrate concentration. Soil samples around the animals hut (cows, buffaloes, goats, poultry) in 14 locations in Bogor Regency. These bacterial isolated by using enrichment culture method in specific medium which is developed by Verstraete (1981, in Iswandi, 1989) by using three concentration rates of (NH4)2SO4, such as 250 ppm, 500 ppm, and 1000 ppm (NH4)2SO4. Then, ammonium and nitrate concentration measured by using Spectrophotometer. The optimum activity of nitrifying bacterial was found in spesific medium with concentration rate 500 ppm (NH4)2SO4 and 4th day after incubation. The fastest “Nitrosomonas” isolates that can reducing ammonium concentration were NSsp1, NSkm1, NSkm2, NSkm3, and NSsp3, and the fastest “Nitrobacter” isolates that can increasing nitrate were NBsp1, NBkb1, NBam, NBsp5, and NBkm4. These isolates paired, the results got 25 paired of isolates, then also measured the ability in reduced the ammonium and increased the nitrate concentration. The result showed that 5 paired of isolates that had fastest ability in reduced the ammonium and increased the nitrate concentration were NSsp1- NBsp5, NSsp1-NBkm4, NSkm2-NBkb1, NSkm3-NBkb1, dan NSsp3-NBsp5.