Bioremediation and it's types

1. Bioremediation of soil and water
contaminated from hydrocarbon
and surfactant. Biofilms
By
Pooja R

2. • Introduction
• Hydrocarbon contamination – source, bioremediation methods.
• Surfactants contamination - source, bioremediation methods.
• Advantages and disadvantages.
• Biofilms – Introduction, formation, disadvantage, dissolution.
Table of content

3. Bioremediation
Bioremediation is the process of reduction,
elimination, alteration, and transformation of
contaminants present in the natural
environment like soil, air, and water through
the application of microorganisms, fungi,
green plants, or their enzymes.
It is a waste management technique that uses
biological organisms to break down hazardous
substances into less toxic or non-toxic forms.

4. Hydrocarbon contamination
• Hydrocarbon definition: organic chemical compound that is composed
exclusively of hydrogen and carbon atoms.
• Hydrocarbons are naturally-occurring and form the basis of crude oil, natural gas,
coal, and other important energy sources.
• Products such as solvents of paints dry cleaning and household cleaning
chemicals also contain synthetic hydrocarbon.
• Contamination of hydrocarbon occurs due to the release of toxic organic
substances, petroleum, and pesticides which is a serious concern for the
environment.

5. Bioremediation methods
• Bio augmentation the introduction of cultured microorganisms into a contaminated environment in
order to enhance bioremediation of pollutants. It is the addition of selected microbial species,
harboring specific catabolic abilities, into a contaminated environment. However, this technique
involves the application of indigenous microorganisms to the sites to be decontaminated.
• Bio stimulation consists in the addition of different substance to polluted environments to stimulate
the natural biodegradation by indigenous degrading microorganisms. The bio stimulation increases the
growth of indigenous hydrocarbon degraders by the addition of growth-limiting nutrients.
• Land farming is a bioremediation approach, also known as land treatment or land application. This
bio treatment process involves the spreading of excavated contaminated soils or sediments in a thin
layer on a suitably prepared surface. In addition, the stimulation of the microbial activity in the soil is
performed through the aeration and/or the addition of minerals and nutrients.

6. Surfactants contamination
• Definition : surfactants are the compounds that lowers the surface tension. They
are the surface active agent such as detergents that when added to liquid reduces
it’s surface tension there by increasing its spreading and wetting properties.
• Eg : benzalkonium chloride, Sodium stearate
• The elevated concentration of surfactants and their degraded products disrupts
microbial dynamics and their important biogeochemical process, hinders plant
survival and ecological niche and retard the human organic and systemic
functionalities

7. Bioremediation of methods
• The biologically-mediated breakdown of chemicals specifically designed to resist
biologically-mediated breakdown is an obvious challenge.
• Quaternary ammonium compounds (QACs) have a number of common uses such
as wood preservatives, antistatic agents, corrosion inhibitors, and textile softeners.
Widespread use is leading to increasing contamination of water and soils.
• Gliocladium roseum is a fungus capable of secreting enzymes that cleave QACs
result enzymes by-products that are readily broken down by common enzymes.
QAC-treated wood blocks and decompose the toxic preservative.
• The enzymes present in the organism became a great importance as these enzymes
can degrade and metabolize these compounds.
• Example: oxido-reductase and Hydrolases

8. Advantages
Bioremediation being a natural process is accepted by the public as waste treatment method
for contaminated material such as soil and water.
Microbes capable of degrading the contaminant, increase in numbers and produce harmless
product such as carbon dioxide, water, and cell biomass.
Bioremediation is employed for the complete destruction of a wide variation of
contaminants. Many hazardous compounds can be transformed to non-toxic products.
Bioremediation can be performed on site treatment, without causing a major disturbance of
normal activities and thus decreases potential hazards to human health and the environment
that can arise during transportation.
Bioremediation is cost effective in comparison to other methods that are used for removal
of hazardous waste

9. Limitations
Bioremediation is limited to biodegradable compounds.
Products of biodegradation may be more lasting or toxic than the parent compound.
Biological processes are largely specific as presence of metabolically capable
microbial populations, suitable environmental growth conditions, and adequate
levels of nutrients and contaminants are the important sites factors required for
successful bioremediation
Development of complex mixtures of contaminants that are not evenly distributed in
the environment i.e. It may be present as solids, liquids, and gases.
Bioremediation consumes much time compared to other treatment options, such as
excavation and removal of soil from contamination.
Due to that performance evaluation of bioremediation is complex, and there is no
fixed endpoint for bioremediation treatments

10. Biofilms
• Biofilm is defined as a community of bacteria enclosed in a self-
produced exopolysaccharide matrix that adheres to a biotic or abiotic
surface.
• The microorganisms form an attachment to the surface of the object by
secreting a slimy, glue-like substance.
• Surface of attachment: metals, plastics, natural materials (such as
rocks), medical implants, kitchen counters, contact lenses, the walls of
a hot tub or swimming pool human and animal tissue etc..

11. Formation of biofilms
• Free cells moves closer
• Secretion of extracellular Polysaccharides
• Attachment to the surface
• Irreversible attachment to the surface
• Maturation of the colonies
• Formation of micro colonies
• Dispersion of cells

12. Formation of biofilms

13. Properties of biofilms
1. Cooperation : Horizontal Gene transfer carrying antibiotics
resistance and virulence is favoured inside biofilms.
2.Survival : Biocide are mostly tested against the free-floating bacteria,
so the matrix of biofilms enhances the survival even when exposed to
antimicrobials.
3.Complexity : cells in biofilms have ability to undergo differentiation,
continues remodeling that helps species to develop a specific matrix
composition.

14. • Biofilm formation poses a significant problem to the drinking water
industry
• They are potential source of bacterial contamination, including
pathogens. In many cases they also affecting the taste and odor of
drinking water and promoting the corrosion of pipes
• It can cause fouling of the equipment, contaminate products and
damage the water distribution system.
• It can cause contamination of the fuel and souring of the chemicals
due to the excretion of H2S by the biofilm bacteria.
Disadvantages of biofilms

15. Dissolution of biofilms
• Biofilms enables bacteria to survive in wide range of conditions i.e
1000 times more tolerant to biocides. They build up protective barrier
around infectious microbes.
• It is impossible to disinfect or even to sterilize
• Organic and inorganic materials interfere with sterilization process.
• To dissolve a biofilms we can use the enzymatic methods.
• This method can Bio mimic the microbes that naturally develop
enzyme to free themselves from biofilms matrix.

16. Reference:
• Microbial Degradation of Hydrocarbons—Basic Principles for Bioremediation
Andreas P. Loibner et al. Encyclopedia of Toxicology (Third Edition), 2014
• Biodegradation and bioremediation in extreme environments Jesús Bernardino
Velázquez-Fernández et al. Submitted: August 1st, 2012
• Biofilms: Microbial Life on Surfaces Rodney M. Donlan et al. 2019
• Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water
Distribution Systems Sanly Liu et al. Environ Sci Technol. 2016