Articles

Isolation and Identification of Indigenous Bacteria for the Degradation of Polycyclic Aromatic Hydrocarbons Found in Refinery Wastewater

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Polycyclic aromatic hydrocarbon (PAH) degrading bacteria were screened and isolated from contaminated soil taken from Tema Oil Refinery wastewater effluent channels. Refinery wastewater was found to contain a low amount of inhibitory heavy metals but the presence PAHs were detected and identified. The PAH-degrading bacteria isolated and identified were Pseudomonas stutzeri. Acinetobacter junii, Pseudomonas putida and Stetonotrophomonas nititireducens. All four bacteria showed high tolerance to a PAH combination of Naphthalene and Anthracene (1:1) of concentration as high as 5mg/ml. The identification of S. nititreducens as an indigenous bacterium is very significant since it is one of the very few bacteria known to be able to degrade high molecular weight PAHs.

Polycyclic Aromatic Hydrocarbons and Respiratory Toxicity: A Review

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Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants primarily associated with chronic respiratory illness. Increased epidemiological findings necessitate a concentrated effort to raise awareness regarding the influence of air quality on the prevalence of highlighted PAHs in airborne particles. PAHs have been associated with respiratory problems including asthma, asthma exacerbation, chronic bronchitis, and emphysema The review gives an insight into the recent PAHs exposure and its toxicity effects on the respiratory system. A literature search across four scientific databases yielded 120 relevant studies, including articles analyzing urinary concentrations of various persistent PAHs and their biomarkers. The study also highlighted the risk posed by PM2.5-PAHs conjugates in causing mutagenesis, carcinogenesis, teratogenesis, disrupting signalling pathways resulting in oxidative stress, acute and/or chronic respiratory morbidity, cognitive impairment, cardiovascular morbidity, and mortality. The study further emphasizes PAHs’ and their metabolites’ significant toxicity to the respiratory system, inducing AhR/nonAhR interlinked signalling mechanisms that lead to oxidative stress, immune system damage, asthma/COPD, and cancer. In conclusion, the study predominantly indicates positive correlations between PAHs and respiratory toxicity.

Biodegradation of Polycyclic Aromatic Hydrocarbon Compound by Bacterial Cultures

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In the present study biodegradation of Polycyclic Aromatic Hydrocarbon (PAH) compound Naphthalene by four bacterial cultures Bacillus subtilis PD6, Bacillussp. PD9, Enterobactersp. PD11 and Bacillussp. PD14 has been targeted. Biodegradation of Naphthalene by these four selected bacterial cultures was analysed by HPLC (High Performance Liquid Chromatography) technique. HPLC analysis revealed biodegradation of naphthalene by all the four bacterial cultures within a span of six days. Highest biodegradation 78.1% has been shown by Bacillus subtilis PD6 while other bacterial cultures Bacillus sp. PD9 has shown 77.90%, Enterobacter sp. PD11 showed 74.4% and Bacillus sp. PD14 exhibited 73.5% biodegradation of naphthalene.