atmosphere and the aqueous environment, harming human health via the food chain.
Human activity is regarded as the main cause of heavy metal pollution of soils.
Various industrial operations (e.g., metal forging, mining, manufacturing batteries,
combustion of fossil fuels, smelting), agrochemicals, and long-term release of
Fig. 4.2 Diagrammatic model shows the process for reducing ethylene levels in roots by using
bacterial 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase. ACC synthesized in plant
tissues is believed to be exuded from plant roots and is taken up by rhizobacteria where ACC is
hydrolyzed to ammonia and 2-oxobutanoate. (Source: Tak et al. 2013)
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