Lead Tolerant
Chryseobacterium indologenes HMT 47 showing Plant Growth Promotion in Maize
Sen Monica and Joshi Harshada
Res. J. Biotech.; Vol. 20(8); 237-241;
doi: https://doi.org/10.25303/208rjbt2370241; (2025)
Abstract
The study of metal-tolerant bacteria is important for transformation of toxic metal
ions into less toxic compounds and bioremediation of contaminated environments.
The present investigation was implemented to search for high efficient bacterial
strain in bio-remediating the toxic influence of lead nitrate (PbN2O6) on maize
plantlets grown in soil supplemented with lead nitrate. Seventeen strains were isolated
on nutrient agar supplemented with 0.1mM lead nitrate from the rhizosphere of different
plants (Tridax, Calotropis and Acacia) growing in polluted soil of tailing dam in
Zawar, Udaipur, India. The minimal inhibitory concentration of lead tolerant bacterial
isolates ranged from 200 to 1000 μg/ml. Isolate HMT 47 showed highest MIC value
(1000 μg/ml) and was further characterized by morphological, cultural, biochemical
and molecular characterization.
It was identified as Chryseobacterium indologenes HMT 47. The bioaccumulation of
Pb by the strain was evidenced by transmission electron microscopy. A pot experiment
under Pb stress conditions was performed using Zea mays L. as a test crop. Pb toxicity
reduced various plant growth parameters; however, bioremediation of Pb contaminated
soil with Chryseobacterium indolegenes HMT 47 significantly increased maize plantlet
shoot, root length, fresh and dry weight of shoot and root compared to the uninoculated
treatments.
