Molecular Analysis of Dichloropropionate Degrading Bacterium Isolated From Sediment Using 16S Elham Khosrowabadi and Fahrul Huyop Department of Industrial Biotechnology Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia 81310 UTM Skudai, Johor Bahru, Malaysia Elham.khosrowabadi@gmail.com Abstract—Halogenated compounds are widely used in agriculture and industries and have been associated with environmental pollution and their toxicity potential. Dredging along the coastal regions of Singapore considering as challenge for marine dehalogenase bacteria. The aim of the current study was to isolate and identification of 2, 2-dichloropropionic acid (2, 2-DCP) degrading bacteria from marine sediment. A soil bacterium was isolated from marine sediment of East coast of Singapore using streak plate method. Pure culture was obtained by streaking onto 20 mM of 2, 2-dichloropropionic (2, 2-DCP) repeatedly. The culture was incubated for 4 days at 30 °C, incubator shaker aerobically. Based on partial 16S rRNA gene sequence, the isolated strain EK1 showed 96% sequence identity to Lysinibacillus sphaericus strain HNS006. Biochemical tests and microscopic observation support the results and suggested that the genus belongs to Lysinibacillus. sp. This bacterium has the ability to degrade 2, 2-dichloropropionic acid (2, 2-DCP) at 20 mM with cells doubling time of 30.71±0.1 h in 2, 2-DCP minimal medium. I. INTRODUCTION Most of the Marine habitat and coastal areas of the world have been reported to be damaged from pollution, significantly affecting commercial coastal and marine fisheries [1]. Pervious study showed that sediments present in the harbors are often contaminated with pollutants from a wide range of agricultural, urban and industrial sources, and typical contaminants including toxic metals, organo-halogen and petrochemical products [2]. Halogenated compounds constitute one of the largest groups of environmental pollutants, and mainly higher halogenated compounds are known to accumulate especially in anoxic environments like sediments and harbor sludge due to their enhanced hydrophobicity [3]. It is also important to note that the marine environment are an incredibly rich source of halogenated compounds produced naturally by marine plants and animals or industrial activities [4]. Thus, marine sediments are considering significant sinks for halogenated compounds. Contamination of these habitats constitutes a serious environmental and human health problem mainly due to the high toxicity exhibited by some polycyclic aromatic hydrocarbons and halogenated compounds which are prevalent in many fuel mixtures and have mutagenic and carcinogenic properties [5, 6]. Therefore, there is a significant demand for environmentally safe and economically feasible technologies for treatment of contaminated sediments. These substances can be decontaminated using non-biological or microbiological degradation [7]. Microbial processes base on the metabolic activities of bacteria are especially attractive to reduce the toxicity of the contaminated sediments [8]. Bioremediation processes include treating pollutants with hydrocarbon- degrading microorganisms that are generally ubiquitous in nature and are able to use different types of hydro-carbons as a carbon and energy source [9]. Dehalogenation is the only known biodegradation mechanism for certain significant pollutants. It generally makes xenobiotic compounds less toxic and more readily degradable Dehalogenation is the critical step in the degradation of chlorinated aliphatics, because the reaction occurs as the first step in the degradative pathway without any regard to the mechanisms of hydrolytic, oxygenolytic, or reductive dehalogenation [10, 11]. Dehalogenase enzymes that catalyze the cleavage of carbon-halogen bonds receive greater attention because of their potential use in biotechnological applications in the bioremediation of halogenated environmental pollutants [12]. To isolate bacteria from marine sediment growth on 2, 2- dichloropropionate (2,2-DCP) minimal medium as sole source of carbon and energy is considered. 2,2-dichloropropionic acid 2, 2-DCP (Dalapon) is a xenobiotic compoundused as herbicide and would be able to pollute a water source easily [13]. Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia Civil Engineering Proceedings of 4th International Graduate Conference on Engineering, Science and Humanities IGCESH, 2013 ISSN: 1823-3287 700