Introduction

1. Diversity of Denitrifying Bacteria in Four Soda Lakes of Ethiopia Lulit Tilahun1,Baye Sitotaw1,Amare Gesesse1and Lise Øvreås2 1Biotechnology Program, Addis Ababa University, P O Box 1176, Addis Ababa, Ethiopia 2Department of Biology, University of Bergen, Bergen, Norway , Introduction Denitrifiers are important for nitrate removal in biological waste water treatment plants. However, effluents from industries such as Tanneries have high pH. Hence denitrifiers taken from naturally alkaline environments like Soda lakes are important to treat the waste water. Since Ethiopia has many soda lakes, the possibility of finding high pH tolerating denitrifiers that can easily adapt the conditions of the treatment plants is great. Table: ARDRA GROUPS . . Objective To study the diversity and distribution of denitrifying bacteria among four soda lakes of Ethiopia, namely, Lakes Abijata, Shalla, Chitu and Arenguade Methods The DNA of the tested denitrifiers was extracted and 16SrRNA gene was amplified. The ARDRA table was made by digesting the 16SrRNA gene using RsaI and Alu I endonuclease restriction enzymes. Selected representatives from each ARDRA groups were sequenced and Phylogeny tree was constructed Cluster I Results Alu I 1KB C23 C39 C 3 C18 C38 C4 C36 A10 A7 A18 C32 A14 A15 1KB Cluster II Figure: locations of the studied lakes Cluster III Rsa I 1KB C23 C39 C 3 C18 C38 C4 C36 A10 A7 A18 C32 A14 A15 1KB • Conclusion • Denitrifiers were present in the four studied soda lakes • H. campisalis, H. salina, H. nitritophilus, B. cohnii, B. pseudofirmus were highly similar with the studied isolates • Nitricolalacisaponesis showed less than or equal to 98% similarities with the representatives of all four lakes Figure: Images of Restriction fragment patterns obtained using Alu I and RsaI enzymes • Acknowledgment • NUFU project • Addis Ababa University