1Magaji Yakubu, 1,2Muhammad Bashir Sanda*., 1Nkechi Eucharia Egbe.
¹Department of Biotechnology, Faculty of Science, Nigerian Defence Academy, Kaduna, Nigeria
2Department of Biological Sciences, Faculty of Science, Kashim Ibrahim University, Borno State, Nigeria
*Corresponding author’s Email: Muhammad.sanda2022@nda.edu.ng, doi.org/10.55639/607.02010082
ABSTRACT
Heavy metal contamination of soils around automobile workshops poses serious environmental and public health risks due to the persistence and toxicity of metals such as cadmium (Cd), lead (Pb) and copper (Cu). This study investigated the influence of Lysinibacillus fusiformis on the phytoremediation performance of Helianthus annuus grown in contaminated soils from New Panteka, Kaduna State, Nigeria. Baseline soil metal concentrations were determined from single composite samples at three contaminated points (A–C), while post-phytoremediation concentrations were analysed in triplicate after a 30-day growth period. Metal concentrations in soil and plant tissues were quantified using atomic absorption spectrophotometry. Following phytoremediation, substantial reductions were observed for Pb and Cu, particularly at Point C. Soil Pb decreased from 392.50 mg/kg to 49.42 ± 15.04 mg/kg, while Cu decreased from 55.50 mg/kg to 12.22 ± 8.57 mg/kg, both falling below World Health Organization guideline values. In contrast, Cd remediation was inconsistent, with soil Cd concentrations remaining above the permissible limit (0.8 mg/kg) at all points after treatment and exhibiting negative or marginal metal removal efficiencies at some sites. High standard deviations observed for several metals indicate considerable spatial and experimental variability. Plant tissue analysis showed higher accumulation of Pb and Cd in inoculated plants compared to non-inoculated controls, suggesting increased metal bioavailability associated with microbial activity. The results indicate that L. fusiformis influenced Pb and Cu phytoremediation trends in H. annuus, while Cd remained poorly remediated under the experimental conditions. The findings highlight the potential and limitations of microbial-assisted phytoremediation in heterogeneous, metal contaminated urban soils.
Phytoremediation,
Helianthus annuus,
Heavy metals,
New Panteka.

