RESUMO
Aims: To confirm the ability of Anoxybacillus rupiensis strain Ir3 (JQ912241) to utilize the aromatic compounds using FTIR and HPLC analyses. Study Design: Experimental study. Place and Duration of Study: Department of Biotechnology, College of Science, Al-Nahrain University. Baghdad, Iraq, between December 2012 and April 2013. Methodology: Anoxybacillus rupiensis strain Ir3 (JQ912241), a newly thermophilic bacterium, isolated from hydrocarbon contaminated soil in Iraq, was used. Analytical experiments include HPLC (High performance liquid chromatography) and FTIR (Fourier transform infrared) were used to determine the ability of this strain to utilize the aromatic compounds. Results: The quantitative analysis (HPLC) indicated that this bacterium showed as much as 99.62% consumption of carbazole, 99.4% of ρ-nitrophenole, 97.73% of nitrobenzene and 98.89% of naphthalene. Qualitative analysis of FTIR spectra showed that A. rupiensis strain Ir3 (JQ912241) has the ability to convert carbazole to anthranilic acid, indicating the presence of the meta cleavage enzyme, this also confirmed by using 2, 3-dihydroxybiphenyl through converting the colony color on Luria-Bertani (LB) and minimal agar plates to brown. Conclusion: The good ability of A. rupiensis strain Ir3 to utilize the studied aromatic hydrocarbons make it a good candidate as biocatalist. Its ability to convert carbazole to anthranilic acid and to oxidize catechol to 2-hydroxymuconic semialdehyde is through the meta cleavage enzyme.
RESUMO
Aims: To study the effect of curing agents on A. rupiensis Ir3 (JQ912241) plasmid(s) and the plasmid(s) role in utilization of carbazole in this bacterium. Study Design: Experimental study. Place and Duration of Study: Department of Biotechnology, College of Science, Al-Nahrain University. Baghdad, Iraq, between October 2012 and February 2013. Methodology: Anoxybacillus rupiensis strain Ir3 (JQ912241) a newly thermophilic bacterium capable to utilize aromatic hydrocarbons, was used. Plasmid profile of this bacterium was determined. This bacterium was treated with two curing agent’s in order to cure their plasmids. Results: Plasmid profile of A. rupiensis strain Ir3 (JQ912241) showed that this bacterium contains large and small plasmid DNA bands. In order to determine the role of plasmid in utilization carbazole, many attempts were made to cure plasmid (s) of this bacterium using Sodium Dodecyl Sulfate (SDS) and Ethidium Bromide (Et.Br). Results indicated that no cured colonies (lost their ability to utilize carbazole at 70°C) were obtained. P lasmid isolated from some of these colonies being treated with Et.Br, indicated that these colonies are still harboring the large plasmid. Conclusion: It was difficult to cure the large plasmid, and the utilization trait might be located on it or on the chromosome.