Identification and characterization of Raoutella ornithilolytica and determination of its herbicide 2,2-dichloropropionate (2,2-DCP) degradation potential

Abstract

Aims:The goal of the study is to isolate new bacteria species which are capable to utilizing 2,2-dichlropropionic acid (2-2-DCP) as a sole carbon source from the wastewater sample that was taken from Tioman Island off the coast of Malaysia. Methodology and results: Genomic DNA from unknown bacterial strain (MR1) was extracted and PCR amplification was carried out using universal primers, Fd1 (5'-AGA GTT TGA TCC TGGCTC AG-3') and rP1 (5'-ACG GTC ATA CCT TGT TAC GAC TT-3') prior to sequencing. The BLASTn and phylogenetic analysis of the 16S rRNA of the MR1 gene found it shares a 95% homology to an aerobic bacillus Raoutella ornithilolytica. The bacteria which is usually found in an aquatic and hospital environment was found to possess a distinctive feature of being able to utilize 2,2-DCP as sole carbon source. The bacteria has cell doubling time of 23.11 h and maximum release of chloride ion at 0.257 mmol/L in 20 mM 2,2-DCP. Based on morphological and partial biochemical characteristics, the strain was found to be non-motile, Gram negative bacteria with red colonies that gave a positive catalase reaction. Conclusion, significance and impact of study: A better understanding of newly isolated microorganisms from the environment which can potentially be used as bioremediation tools in environmental management. This is the first reported case of Raoutella sp. that has the unique ability to degrade halogenated compound. Hence, the dehalogenation properties and capabilities of the bacteria deserve to be assessed further.