Abstract
Rapid growth of industrial sector and lack of proper disposal of industrial wastes heavily loaded our soil reservoirs with toxic metals which is a serious threat to all form of life. Among other mechanisms, lipid per-oxidation is a major threat to biological matrix. The aim of this research work was to evaluate the lipid peroxidation induced by heavy metals in spinach that is mediated by microbes (Bacillus spp. and Coryne bacterium spp.) isolated from contaminated soils irrigated with industrial effluents of Gadoon Industrial Estate, Swabi (GIES) and Hyatabad Industrial Estate, Peshawar (HIEP). The severity of the lipid peroxidation induced by heavy metals was determined by malondialdehyde (MDA) contents, glycine betaine (GB), proline (Pro), hydrogen per oxide (H2O2) contents, photo synthetic pigments (Chlorophyll "a", Chlorophyll "b" and "Carotenoids), total soluble sugar (TSS), total soluble proteins (TP), and cell viability (EC) estimation. Heavy metals contaminated soil significantly affected the photo synthetic system of the plant by lowering the content of Chlorophyll "a", Chlorophyll "b", carotenoids, total soluble sugar and total soluble proteins, while electrolyte contents, glycine betaine, proline, hydrogen peroxide and malondialdehyde contents in terms of lipid peroxidation were increased. Whereas the seeds inoculated with microbes showed significant increase in photo synthetic pigments, total soluble sugar and proteins contents with low cell leakage, glycine betaine, proline, hydrogen peroxide and malondialdehyde contents showing decrease in oxidative stress produced by heavy metals. Present results revealed that microbes inoculated plants showed low degree of lipid peroxidation which also confirmed the key role of microbes in bioremediation. Interestingly, Coryne bacterium spp., shows improved resistance to heavy metals contamination than Bacillus spp.