Biodegradation potentials of polyaromatic hydrocarbon (pyrene and phenanthrene) by Proteus mirabilis isolated from an animal charcoal polluted site

Indiscriminate disposal of animal charcoal from skin and hides cottage industries often impact the environments with toxic hydrocarbon components and thus require eco-friendly remedial strategies. A bacterial strain isolated from a site polluted with animal charcoal was characterized, identified as Proteus mirabilis 10c, and studied for ability to degrade pyrene and phenanthrene. The bacterium resisted 30 µg chloramphenicol, 10 µg ampicillin, 30 µg amoxicillin and 10 µg perfloxacin; while it utilized a number of polycyclic aromatic hydrocarbons and cinnamic acid. Specific growth rate on pyrene and phenanthrene were 0.281 d−1 and 0.276 d−1, respectively. Kinetics of degradation of pyrene was 87.92 mg l−1 in 30 days at the rate of 2.93 mg l−1 d−1, biodegradation constant at 0.073 d−1 and half-life of 9.50 d. The corresponding values for phenanthrene degradation kinetics by the bacterium were 90.12 mg l−1, 3.02 mg l−1 d−1, 0.079 d−1 and 8.77 d, respectively. Efficient degradation of crude oil (92.3%) in chemically defined medium was evident with near-disappearance of most aromatic spectra in 30 days. Considering its unique physiologies and broad specificities for aromatic and aliphatic hydrocarbons, the bacterium has potentials for decommissioning environments contaminated with toxic components of animal charcoal

4-Carboxyl-2, 6-dinitrobenzene diazonium ion (CDNBD): a new diazonium for the detection of phenol ether homologues

Pharmaceutical phenol ethers are a heterogeneous group of compounds possessing ether linkage to an aromatic nucleus. Diazo coupling is rare with these compounds and no physicochemical method of analysis has been reported based on the reaction of these ethers with a diazonium ion. The high reactivity of 4-carboxyl-2,6-dinitrobenzene diazonium ion (CDNBD) is therefore investigated in this work. Comparative coupling reaction was done with two other diazonium ions (derived from p-nitroaniline and sulphanilic acid). Twenty-two phenol ethers were selected for evaluation of their reactivity with the three diazonium ions. Such ethers consist of those with naphthalenes, indole and bridged rings. Spot tests were used to establish coupling at room and elevated temperatures. Visual inspection and thin layer chromatographic (TLC) analysis of the reaction mixture provided evidence of coupling or otherwise. UV-VIS absorption spectra were used to characterize brightly coloured adducts, as a preliminary test for the estimation of these ethers by spectrophotometry. Of all the ethers screened, fourteen gave instant and distinct colour from CDNBD while seven of these gave colours of deeper intensity at elevated temperature. Only three of the ethers gave instant colour with diazotized p-nitroaniline while one compound gave instant colour with diazotized sulphanilic acid. UV absorption spectral analysis reveals the superiority of CDNBD for the detection and possible estimation of these ethers. CDNBD is shown to be a highly reactive arenediazonium ion with the possibility of finding usefulness for the determination of phenol ethers by ultraviolet/visible spectrophotometry and precolumn derivatization in high performance liquid chromatographic (HPLC) analysis. Journal of Pharmacy & Bioresources Vol. 2(2) 2005: 146-16