Evaluation of heavy metal content in water and removal of metals using native isolated bacterial strains




Abstract. Saleh LIF, Rashed RO, Muhammed SM. 2021. Evaluation of heavy metal content in water and removal of metals using native isolated bacterial strains. Biodiversitas 22: 3163-3174. Natural surface water sources are susceptible to chemical contamination, including heavy metals. The goals of this study were to isolate naturally occurring heavy metal-tolerant bacteria by evaluating their ability to remove heavy metals from Tanjaro River and assessing the river’s water quality. The potency of bacteria to remove heavy metals (Cd, Pb, Cu, Cr, Ni, Zn, Co, and Fe) from the medium was conducted by inductively coupled plasma-optical emission spectrometry. Results of physicochemical parameters of the water samples were as follows: temperature 11.9–31°C, pH 6.1–8.64, total dissolved solids 268–464 mg.l-1, total hardness 232–485 mg.l-1, and alkalinity 122–324.3 mg.l-1. The overall mean concentrations of the heavy metals were in the order of Zn >Cu> Pb> Ni> Co> Fe> Cr> Cd), with values of 0.086, 0.073, 0.71, 0.068, 0.051, 0.056, 0.031, and 0.024ppm, respectively Moreover, the concentrations were generally exceeded the water quality criteria of WHO in some observations. The isolates included both gram-negative (56.5%) and gram-positive (43.5%) bacteria. The isolates displayed different degrees of resistance to heavy metals with maximum tolerable concentrations (MTCs) ranging from (10-250) ppm. Bacillus safensis and Leucobacter chromiiresistens were respectively able to tolerate (80, 90 ppm) Cd, (250, 160 ppm) Pb, (210,100 ppm) Cr, (110, 90 ppm) Ni and (160, 170 ppm) Co, while, Proteus mirabilis could tolerate 90 ppm Cd. The isolates were able to remove 55.4%Pb, 53.1%Cr, 53.7%Ni, 47.7Fe, 61.4%Co, and 55.8% Cu from a medium supplemented with the mixture of these heavy metals. The finding of this study indicated that Tanjaro River was undergoing frequent changes in water quality. Native bacterial isolates possessed considerable tolerance to selected heavy metals, which provides promising candidates for use in bioremediation.


- Afzal A, Rasool M, Waseem M, Aslam, B. 2017. Assessment of heavy metal tolerance and biosorptive potential of Klebsiella variicola isolated from industrial effluents. AMB Express, 7(1). https://doi.org/10.1186/s13568-017-0482-2.
- Aktan Y, Tan S, Icgen B. 2013. Characterization of lead-resistant river isolates Enterococcus faecalis and assessment of its multiple metal and antibiotic resistance. Environ Monit Assess, 185(6), 5285–5293. https://doi.org/10.1007/s10661-012-2945-x.
- Al- Ameri, M.A. 2011. Soil and Plant Pollution with Some Heavy Metals Caused by Al-Daura Refinery Emissions on the Surrounded Region. M.Sc. Thesis. Univ. of technology/Bagdad.
- Alegbeleye O, Opeolu B, Jackson V. 2017. Bioremediation of polycyclic aromatic hydrocarbon (PAH) compounds: (acenaphthene and fluorene) in water using indigenous bacterial species isolated from the Diep and Plankenburg rivers, Western Cape, South Africa. Braz J Microbiol, 48(2), 314–325. https://doi.org/10.1016/j.bjm.2016.07.027.
- Al-Taei, N. H., Al-mamoori, A. M. J., Al-hmoud, N. 2020. Estimation of physicochemical parameters and antibiotics resistance patterns in Almamierh treatment plant in Babylon Province, Iraq. Eurasia J Biosci 14, 2989-2996 (2020).