<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>This study was conducted to assess the growth performance of <italic>Amaranthus cruentus</italic> on spent-engine-oil- (SEO) contaminated soil bioremediated with bacterial inoculants and processed biostimulants: compost, sole cocoa pod husk (CPH), and sole cow dung (CD). SEO with 5%, 10%, and 15% densities was artificially contaminated with sterilized soil. Subsequently, biostimulants and bacterial inoculants, <italic>Staphylococcus aureus</italic> and <italic>Bacillus cereus</italic>, were applied. The treatments were replicated three times, adopting a completely randomized design<italic>.</italic> After the biodegradation assay that lasted for 70 days, <italic>Amaranthus cruentus</italic> seeds were sown, while its growth parameters, plant height, number of leaves, and stem girth were monitored for 6 weeks after sowing (WAS).<italic></italic> The results generated indicate that the applied biostimulants and bacterial inoculants accomplished significant (P &lt; 0.05) reclamation of the SEO-contaminated soil as the test plant recorded substantial growth compared with the controls that recorded no growth. At 2 WAS, compost influenced the highest plant heights (6.5, 7.4, and 7.5 cm) compared with other biostimulants at 5%, 10%, and 15% SEO contamination levels respectively. At 4 WAS, all biostimulants produced the same number of leaves (5.0) at 5% SEO contamination level, the compost recorded the highest number of leaves (6.0) at 10% SEO contamination level, while all biostimulants produced the same number of leaves (4.0) at 15% SEO contamination level. The study showed that the combination of biostimulants and bacterial inoculants significantly reclaimed SEO contaminated soil. Therefore, reclamation of petroleum-impacted environments with the combination of biostimulation and bioaugmentation is recommended.</p>
</abstract>

This study was conducted to assess the growth performance of Amaranthus cruentus on spent-engine-oil- (SEO) contaminated soil bioremediated with bacterial inoculants and processed biostimulants: compost, sole cocoa pod husk (CPH), and sole cow dung (CD). SEO with 5%, 10%, and 15% densities was artificially contaminated with sterilized soil. Subsequently, biostimulants and bacterial inoculants, Staphylococcus aureus and Bacillus cereus, were applied. The treatments were replicated three times, adopting a completely randomized design. After the biodegradation assay that lasted for 70 days, Amaranthus cruentus seeds were sown, while its growth parameters, plant height, number of leaves, and stem girth were monitored for 6 weeks after sowing (WAS). The results generated indicate that the applied biostimulants and bacterial inoculants accomplished significant (P < 0.05) reclamation of the SEO-contaminated soil as the test plant recorded substantial growth compared with the controls that recorded no growth. At 2 WAS, compost influenced the highest plant heights (6.5, 7.4, and 7.5 cm) compared with other biostimulants at 5%, 10%, and 15% SEO contamination levels respectively. At 4 WAS, all biostimulants produced the same number of leaves (5.0) at 5% SEO contamination level, the compost recorded the highest number of leaves (6.0) at 10% SEO contamination level, while all biostimulants produced the same number of leaves (4.0) at 15% SEO contamination level. The study showed that the combination of biostimulants and bacterial inoculants significantly reclaimed SEO contaminated soil. Therefore, reclamation of petroleum-impacted environments with the combination of biostimulation and bioaugmentation is recommended.

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

Department of Microbiology and Biotechnology

Acta Universitatis Sapientiae, Agriculture and Environment

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

This study was conducted to assess the growth performance of Amaranthus cruentus on spent-engine-oil- (SEO) contaminated soil bioremediated with bacterial...

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

Published Online: Jan 18, 2022

Page range: 1 - 12

Received: Dec 25, 2020

Accepted: Mar 30, 2021

DOI: https://doi.org/10.2478/ausae-2021-0001

Keywords
bacterial inoculants, biostimulants, spent engine oil, contaminated soil

© 2021 Adeniyi Olarewaju Adeleye et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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

Published Online: Jan 18, 2022

Page range: 1 - 12

Received: Dec 25, 2020

Accepted: Mar 30, 2021

DOI: https://doi.org/10.2478/ausae-2021-0001

Keywordsbacterial inoculants, biostimulants, spent engine oil, contaminated soil

© 2021 Adeniyi Olarewaju Adeleye et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
bacterial inoculants, biostimulants, spent engine oil, contaminated soil