Bacteria associated with petroleum hydrocarbon wastes in Kupferberg landfill site, Windhoek.
Loading...
Date
2022-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Namibia University of Science and Technology
Abstract
Petroleum compounds are organic contaminants of great interest due to their extensive dispersal,
stubbornness, versatile structure and harmful elements that have been generally known to belong to
the family of carcinogens and mutagens organic toxins. They contaminate many environments
worldwide and enter the global environment through crude oil spillage, fossil fuel combustion as well
as natural inputs like natural petroleum seepage. A range of indigenous microbes have the ability of
decontaminating, breaking down, transforming and removing these hydrocarbon contaminants from
the environment through biodegradation processes. Therefore, the aim of this study was to isolate
and identify the bacterial strains present in the soil contaminated waste samples collected from the
Kupferberg landfill site in Windhoek and to ascertain their ability to grow efficiently in hydrocarbon
based medium. Collected bacterial strains were grown on nutrient agar and were characterised based
on their colony features and biochemical reactions using the API 20NE identification database system.
Sterile nutrient broth media was inoculated with a loop full of the bacterial isolates supplemented
with 1 ml of sterile old diesel engine oil, and the optical density was measured spectrophotometrically
on a daily basis. The highest mean bacterial count was found out to be 3.6 x 10 CFU/ml in site G, and
the lowest mean bacterial count was found out to be 0.9 x 10 CFU/ml in site I. The bacterial strains
isolated were Aeromonas hydrophila, Stenotrophomonas maltophilia, Sphingomonas paucimobilis,
Pseudomonas luteola, Burkholderia gladioli, Photobacterium damselae, Pseudomonas aeruginosa,
Pasteurella spp., Brevundimonas vesicularis, Burkholderia cepacia, Chryseobacterium indologenes and
Aeromonas salmonicida, and it was observed that Sphingomonas paucimobilis was the predominant
isolate in all the samples. Ten selected bacterial strains were subjected to hydrocarbon utilisation/
degradation test, and it was observed that Pseudomonas aeruginosa strain with a mean average
optical density of 1.738, utilised the hydrocarbon in the medium more efficiently than the other
isolates. The study demonstrated that the isolated Pseudomonas aeruginosa could be considered as
good prospects for the bioremediation of hydrocarbons.
Description
Thesis presented in fulfilment of the requirements for the degree of Master of Health Sciences,
Faculty of Health and Applied Sciences, Namibia University of Science and Technology, Windhoek,
Namibia
Keywords
Bacteria, petroleum hydrocarbon wastes, Kupferberg landfill site, Windhoek - Namibia
Citation
Petelo, F.S.T. (2022). Bacteria associated with petroleum hydrocarbon wastes in Kupferberg landfill site, Windhoek. (Unpublished master's thesis). Namibia University of Science and Technology, Windhoek.