1. The document discusses bioremediation of heavy metals like lead, zinc, cadmium, copper, and selenite which threaten human health, as well as bioremediation of detergents. 2. Heavy metal contamination of soil poses risks to humans and ecosystems, but bioremediation using microbes can transform toxic heavy metals into less toxic forms. Microbes use mechanisms like metal ion efflux and precipitation to develop resistance to metals. 3. Detergents are classified based on properties like water solubility and chemical structure. Naturally occurring and synthetic detergents can be ionic, non-ionic, anionic, or cationic. Bacteria like Pseudomonas aeruginosa and

1. Bioremediation of Metals and Detergent
Dr. Naveen Gaurav
Associate Professor and Head
Department of Biotechnology
Shri Guru Ram Rai University
Dehradun

2. Bioremediation of Metals and Detergent
Exposure to lead (Pb), zinc (Zn), cadmium (Cd), copper (Cu), and
selenite (SeO3−2) consider the main heavy metals that threat
human health. These heavy metals can interfere with the function
of vital cellular components. Soil heavy metal contamination
represents risks to humans and the ecosystem through drinking of
contaminated groundwater, direct ingestion or the food chain, and
reduction in food quality. Bioremediation means cleanup of
polluted environment via transformation of toxic heavy metals into
less toxic form by microbes or its enzymes. Otherwise,
bioremediation by microbes has limitations like production of toxic
metabolites. The efflux of metal ions outside the cell, biosorption
to the cell walls and entrapment in extracellular capsules,
precipitation, and reduction of the heavy metal ions to a less toxic
state are mechanisms to metals’ resistance.

15. Bioremediation of Detergents: Detergent is organic compound that reduce surface tension in
water and other liquids (Kowalska et al., 2004). Detergents contain both strong hydrophobic
and hydrophilic moieties.There are many kinds of detergents, and they are classified by their
use, properties and chemical structure. The detergent classification depends on water
dissociation and the structure of hydrophilic group. According to the water-solubility,
detergents can be classified into ionic detergents and non-ionic detergents. Ionic detergents
can be divided into anionic detergents, cationic detergents and amphoteric detergent.
Detergents may be from natural or synthetic sources. The first category includes naturally
occurring amphiphiles such as the lipids, which are detergents rinsing and/or fabric softening
process due to their surface-active properties and are discharged into the environment by the
wastewater pathway, either after treatment in a wastewater treatment plant or directly
where no treatment system is available.Some examples of detergent degrading bacteria are
Pseudomonas aeruginosa, Escherichia coli ,Klebsiella liquiefaciens ,Enterobacter liquiefaciens,
Klebsiella aerogenes , Bacillus sp. Bacteria were isolated from detergent contaminated soil
near household area and identified by biochemical tests. Methylene Blue Active Substance
was used to determine the amount degradation by the bacteria. S7 strain showed better
degradation for detergent. Degradation was highest during 48 hours of incubation.
Biodegradation is common method for the removal (degradation and detoxification) of
detergent because of its low cost and low collateral destruction of indigenous animal plant
organisms. Bcaterial degradation is considered to be a major factor determining the fate of
detergent in the environment. Degradation of detergent is usually a combination of a number
of processes, including microbial degradation and is also influenced by some physicochemical
properties such as temperature, pH and carbon and nitrogen source.

16. The increasing releases of organic pollutants by industries cause many health–related
problems. However, increased awareness of the harmful effects of environ-mental pollution
has led to a dramatic increase in research on various strategies that may be employed to
clean up the environment. It is now realized that microbial metabolism provides a safer,
more efficient, and less expensive alternative to physico-chemical methods for pollution
abatement. Linear alkyl benzene sulphonates (LAS) is a commonly used anionic surfactant in
detergents and it is easily bio- degraded.
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