Effect of organic amendments on the decontamination potential of heavy metals by Staphylococcus aureus and Bacillus cereus in soil contaminated with spent engine oil

Abstract

This study was conducted to assess the decontamination of heavy metals of an environmental concern in spent engine oil (SEO) contaminated soil, through the adoption of Staphylococcus aureus and Bacillus cereus cocultures, isolated from Dutse mechanic village, Nigeria. About 1.5 kg of autoclaved soil was contaminated with SEO at three levels. The sterilized soil was then amended with compost, powdered cocoa pod husk (CPH), and powdered cow dung (CD). Subsequently, bio-augmentation with bacterial co-cultures (150 ml) was done. Heavy metal concentrations; Arsenic (As), Cadmium (Cd), Chromium (Cr), Nickel (Ni) and Lead (Pb) were estimated at the commencement, at the fifth and tenth week of the study. The factorial experiment was laid out in a completely randomized design (CRD). Results indicate that bio-stimulation adopted through the amendments did not have significant effects on the bacterial decontamination of soil especially at the 5 th week (P> 0.05). CD only influenced the decontamination of Cd at 5% contamination level (0.0008 mg\ kg), compared with compost that recorded the least effect (0.00360 mg\ kg) at the 5 th week. Meanwhile, CPH had the highest decontamination effect on Cr (0.004 and 0.000 mg\ kg) at 10% and 15% contamination levels; respectively, at the 5 th week. However at the 10 th week, complete removal of As was influenced by compost, CPH, and CD using 5%, 10% and 15% SEO contamination levels, respectively (P< 0.05). The decontamination efficacies of S. aureus and B. cereus recorded in this study is an indication of their potentialities for application in bioremediation of heavy metals.

Bio-enhanced removal of hydrocarbon contents from spent engine oil contaminated soil using Staphylococcus aureus and Bacillus cereus co-culture

“…The procedures used by Adeleye et al (2019) were employed for the isolation and identification of the bacteria (Staphylococcus aureus and Bacillus cereus) used as a co-culture for bioaugmentation in this study.…”

Effects of two bacterial inoculants and biostimulants on the growth performance of Amaranthus cruentus at different levels of spent-engine-oil-contaminated soil

“…The three (3) bio-enhancement formulations, compost (generated from the composting of CPH and CD), sole CPH, and sole CD, employed for biostimulation in this study were collected and subsequently processed according to the procedures described by [13] and [14].…”

“…The biodegradation assay conducted in this study was done according to the procedures described by [14]. This involved a bacterial co-culture, which was bioaugmented with the SEO-contaminated soil in each experimental bag apart from the controls, which did not receive such bioaugmentation and biostimulation.…”

Biostimulatory Influence of Biochar on Degradation of Petroleum Hydrocarbon Impacted Soil

“…Bioremediation, on the other hand, which is the use of living creatures, most notably microbes, to break down pollutants in the surroundings into less hazardous forms, has shown promising results and it is economically and ecologically friendly (Nkereuwem et al, 2020). It degrades or detoxifies pollutants that are harmful to human health and/or the surrounding using naturally occurring microbes or plants through biostimulation (addition of nutrients/amendments) of the indigenous populations or bioaugmentation with oxidizing microorganisms (Adeleye et al, 2019).…”

“…Many elements, such as nutrients, pH, temperature, moisture, oxygen, soil characteristics, and the presence of contaminants, might inhibit petroleum hydrocarbon decay in soil (Adeleye et al, 2019). Biochar, according to Xiao et al (2014), is carbon-rich charcoal produced by pyrolysis (thermal decomposition) of organic biomass or agricultural wastes and used as a soil amendment.…”