Eze Chibuzor Nwadibe, Okobo Uchenna Jude and Odo Chuks Kenneth
Department of Microbiology, University of Nigeria Nsukka
Correspondence to: [email protected] ; +234 (0)8151510547
Article Number: SE-J-ARJB-2019.0201001; Volume 2(1), pp 1-9, August 2019
https://doi.org/10.47721/ARJB201901009
ABSTRACT
Heavy metal and hydrocarbon contaminations from the technosphere are critical issues assailing the biosphere today. Though microbes are known to play a major role in restoring petroleum polluted ecosystems, more often than not they are hampered by interferences from other contaminants in the environment. In this study, the effects of lead and mercury on crude oil degradation and utilization by a soil isolate identified as Pseudomonas aeruginosa were investigated. Four different concentrations (50mg, 100mg, 150mg, or 200mg w/v) of each metal salt were used and each administered per liter of medium containing 10% Bonny light crude oil and 2ml of a broth culture of cells of Pseudomonas aeruginosa suspended in normal saline to a level of 0.5% McFarland standard. Hydrocarbon degradation and utilization were assessed through time-course optical density (OD600) and infrared spectroscopy. At low concentrations (50mg and 100mg) the heavy metals significantly (p < 0.05) enhanced the growth of the organism and its utilization of crude oil but at higher concentrations (150mg, 200mg) both growth and utilization declined. The lowest OD was obtained with mercury, suggesting that mercury exhibited higher toxicity to the organism than lead. The appearance in the infra red chart of new bands within the wave number ranges of 1630-1780cm-1, 1710-1780cm-1 and 3590-3650cm-1 were interpreted from standard manuals to mean the emergence of the aldehyde, carboxyl and hydroxyl functional groups respectively which suggest an oxidative dissimilation of the oil. The effects of the heavy metals used in this study on the hydrocarbonoclastic efficacy of Pseudomonas aeruginosa were metal-dose and metal- species-dependent.
Key words: Technosphere, Pollution, Lead, Mercury, Restoration, ecosystem
Copyright © 2019 Author(s) and Skies Educational.
This article is published under the terms of the Creative Commons Attribution License 4.0
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Article Number: se-j-arjb-2018.0101001