Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

ABILITY OF NITRATE REMOVAL AND GROWTH BEHAVIORS OF ISOLATED BACTERIA FROM DAIRY FARM AT TROPICAL AREA

NANUNG AGUS FITRIYANTO, FEBRI INDRI YANI, YUNY ERWANTO SUHARJONO TRIATMOJO AND AMBAR PERTIWININGRUM

Abstract

Dairy farm and other livestock industry usually generate odour by animals. It possibly cause environmental problems such as ammonia emission in high concentration which can reduce productivity of dairy cows and other animals as well as endanger the health of person who are living inside the farm or community and those who are living nearby livestock industry. The transformation of volatile ammonia to non-volatile form are a primary biological treatment process comprising of nitrification and denitrification processes. The aim of this research was to isolate bacteria which have the ability in reducing nitrate through denitrification process from the dairy farm in the tropical area. Bacteria strains were screened from the soil and observation of the potential of these strains in reducing nitrate was performed. This research was first conducted in isolation of bacteria which has the ability in reducing nitrate. Four bacteria which able to reduce nitrate were successfully isolated from the soil sample. Strain SP1 which was isolated from the soil at the dairy farm of Faculty of Animal Science UGM has the ability for better growth in liquid and solid medium with the addition of nitrate in high concentration. The colony diameter of Strain SP1 growing at different concentration of nitrate 0; 2.5; 5; 7.5 and 10% were observed 0.876; 0.793; 0.952; 0492 and 0.015 cm respectively. All strains have optimal ability to reduce nitrate in the liquid medium. Based on the observation of nitrate reduction in the liquid medium, Strain SP1 reduced 63.48%, Strain SP3 reduced 63.38%, Strain SP4 reduced 62.47% and Strain SP2 has reduced 62.03%. Some physiological characteristics of four denitrification strains are investigated as follow: Strain SP2 and SP4 could produce catalase enzyme while SP1 and SP3 could not produce the same enzyme. Strain SP1, SP2, and SP3 were observed as Gram-negative bacteria while SP4 was Gram-positive. Strain SP1 and SP3 have coccus shape while SP2 and SP4 are observed as Bacillus shape. The conclusion of this research was that isolated bacteria from the soil around the dairy farm have ability to reduce nitrate and have a better growth at 7.5% nitrate containing medium.