Page 259 - C:\Users\am_se\OneDrive - Higher Education Commission\Desktop\FlipBook\

International Conference on

Recent Trends in Environmental Sustainability

ESCON22/SAgri/36

Isolation and characterization of eco-friendly heavy metals resistant bacteria from
waste water contaminated soil
Muhammad Nasir1, Muhammad Tahir1, Muhammad Imran1, Muhammad Asif Naeem1,
Muhammad Shahid2, Abu Bakar Umer Farooq1, Muhammad Ijaz3, Tahir Naqqash4
1Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus
2Department of Bioinformatics and Biotechnology, Govt College University Faisalabad
3Department of Agronomy, College of Agriculture, BZU Bahadur Campus, Layyah
4Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, Multan
Correspondence: muhammad_tahir@cuivehari.edu.pk
Abstract

In arid areas the irrigation of agriculture land with wastewater is common practice. This
practice has serious threats for public health as well as environmental aspects. Prevailing
chemical-based strategies under use to remediate the heavy metals are too much costly and are
not eco-friendly. The use of microbe as heavy metal bioremediation strategy has become an
environment friendly approach in recent era. Keeping all these aspects under consideration, the
present study was conducted to isolate the bacteria equipped with heavy metal remediation and
plant growth promoting potential. A total of four bacterial isolates M50-3/1, WWCd-5/1,
WWCd-5/2 and WWCd-5/3 were obtained from the sewage water and sewage water irrigated
agricultural soil. Maximum inhibitory concentration (MIC) of the isolates was recorded by
growing the isolates on various concentrations ranging from 50-2000 mg/L of cadmium (Cd),
zinc (Zn), arsenic (As) and lead (Pb) using CdCl2, zinc sulphate, sodium arsenate and lead
nitrate as their salt, respectively. The isolate M50-3/1 showed tolerance to the all concentrations
ranging from 50-2000 mg/L of Cd, Zn and Pb but the MIC of the isolate M50-3/1 with respect
to As was 100 mg/L. The isolate WWCd-5/1 was able to grow on all concentrations (50-2000
mg/L) of Zn, Pb, As and Cd. The isolate WWCd-5/2 showed growth on all concentrations of
Zn, Pb, As and Cd with exception that the isolate was unable to grow on As at 2000 mg/L. The
bacterial isolate WWCd-5/3 was able to grow on various concentrations (50-2000 mg/L) of Zn,
Pb and Cd but MIC value of the isolate for As was 500 mg/L. In the presence of all metals (500
mg/L of each metal), the bacterial isolate M50-3/1 solubilized maximum amount of phosphate
(P) and produced maximum amount of indole-3-acetic acid (IAA). The bacterial isolate
WWCd-5/1 solubilized higher amount of P and produced maximum amount of IAA in the
presence of 500 mg/L lead. In the presence of 500 mg/L arsenic (As), the bacterial isolate
WWCd-5/3 produced maximum amount of IAA while the isolate WWCd-5/2 showed highest
P solubilization at this As dose. In the presence of 500 mg/L cadmium (Cd), the bacterial isolate
M50-3/1 produced highest amount of IAA while the same isolate solubilized maximum amount
of P in 500 mg/L zinc (Zn). The bacterial isolate WWCd-5/3 solubilized maximum amount of
P in 500 mg/L Cd. The values of total protein (TP), APX, catalase and POX were produced
maximum in the bacterial isolates WWCd-5/2, WWCd-5/1, M50-3/1 and WWCd-5/3,
respectively in the presence of 500 mg/L each of As, Cd, Pb and Zn as combine form. In mini
pilot plant assay, highest amounts of As, Pb and Zn was detected in treatment T1 while the
minimum values of these metals were detected in T4 treatment.
Keywords: Bacterial Isolates, Maximum inhibitory concentration, Public Health

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

226