Genetic modification in environmental remediation

GENETIC MODIFICATIONS

Sourav MahajanM.Sc. 3rd sem

AIMT

LET’S WATCH SOME PAST AND PRESENT CONDITIONS

OF OUR MOTHER EARTH.

PRESENT SENARIO OF THIS WORLDWORSE!!!

In 2009, near Krichim, Bulgarial, volunteers clean up discarded plastic bottles and garbage clogging up the dam.

Antarctic penguins on ice floes. Global warming has threatened the survival of the polar animals.

Iceberg in Antarctica. Affected by global warming, the two poles are beginning to melt.

Brazil, a nut tree forest destroyed by a large fire.

The almost dried-up Curuai Lake in Brazil.

Comparison pictures of Everest glaciers. The above photo is the Rongbuk Glacier during an analysis of Everest in 1968 by the Chinese Academy of Sciences; The bottom photo was taken by Greenpeace in 2007 of the Rongbuk Glacier.

Comparison pictures of the Heyuan glacial lake. The above picture was taken by Greenpeace’s John Novis in June of 2005; The bottom picture was taken by Greenpeace’s Du Jiang in September of 2005.

2009 December 6, Jammu, India: A person searches for recyclable materials inside the Tawi River.

Tuvalu: Ocean waters flood a hole dug for coral. Data shows that the country of Tuvalu will be submerged by the ocean in 50 years.

In a fish farm in Linzhang Village on the outskirts of Changzhi City of Shanxi Province, husband and wife fish farmers from Fujian province Cheng Daocheng and Cheng Jinlan reluctantly dispose of the catfish that have frozen to death. China News Agency (Fao Yaolin photo)

Tourists sit on the open-air cafe tables, the chairs having already been submerged by flood waters. November 30, Venice, Italy, was again submerged by flood waters influenced by tropical storm tides, with the water level reaching as high as 1.31 meters in certain areas. Photos from: China News Web

2008 November 24, Yichang City of Hubei province, two man-made culverts continuously “vomit” ink-like sewage into the Yangzte River, dyeing the river water black. China News Service (Pu Xinyang photo)

September 23, dust storms occurred in the eastern region of Australia that includes Sydney, affecting the local traffic. With the entire city of Sydney enveloped in an orange cloud of dust, and owing to very low visibility, airplanes and ferries were temporarily grounded or suspended.

WHAT WILL BE THE FUTURE THEN??

Don’t ask the planet what’s wrong, we need to ask ourselves!

THREE STRATEGIES ARE WORKING CONJOINTLY-

1. Through chemical means2.Through biological means

3. General awareness

LETS GET BACK TO OUR STRATEGIES TO CURBTHIS DEVIL

There are 3 mode of biological remediation1. Through natural action of microbes-bioremediation.2. Through natural action of some plants- phytoremediation.3.Through genetic modifications in microbes and

in plants.

Remediation by using living machines!!

Phytoremediation describes the treatment of environmental problems (bioremediation) through the use of plants which mitigate the environmental problem without the need to excavate the contaminant material and dispose of it elsewhere.

Plants can break down, or degrade, organic pollutants or stabilize metal contaminants by acting as filters or traps.

Phytoremediation

PHYTOREMEDIATION

Bioremediation or bioaugmentation is the process of using naturally occurring microbes to digest and convert unwanted waste material into harmless substances.

Bioremediation

Deinococcus radiodurans bacteria have been genetically modified to digest solvents and heavy metals, as well as toluene and ionic mercury from highly radioactive nuclear waste.

Geobacter sufurreducens bacteria can turn uranium dissolved in groundwater into a non-soluble, collectable form.

Dehalococcoides ethenogenes - The bacteria are naturally found in both soiland water and are able to digest the solvents much faster than using traditional clean up methods.

MIGHTY MICROBES

An enzyme from a bacterium, Thermus brockianus, found in Yellowstone National Park, breaks down hydrogen peroxide 80,000 times faster than current chemicals in use.

The bacterium, Alcaligenes eutrophus, naturally degrades 2,4-D, the third most widely used herbicide in the U.S.

MIGHTY MICROBES

GENETIC MODIFICATIONS IN MICROBE GENETIC MODIFICATION IN PLANTS PRODUCTS OF MICROBES LIKE

NANOPARTICLES AND PHB GRANULES

GENETIC MODIFICATIONS

ALREADY KNOWN BIOREMEDIATING BACTERIA-

Pseudomonas, Alcaligenes. A NEW ENTRY IN THIS GROUP NAMED AS

Shewanella. August 31, 2009 The team of researchers from the Georgia

Institute of Technology, Michigan State University and the Pacific Northwest National Laboratory analyzed the gene sequences, proteins expressed and physiology of 10 strains of Shewanella.

GENETIC MODIFICATION IN MICROBES

Shewanella STRAINS.

Similar to a human breathing in oxygen and exhaling carbon dioxide, many Shewanella microbes have the ability to “inhale” certain metals and compounds and convert them to an altered state, which is typically much less toxic.

This ability makes Shewanella very important for the environment and bioremediation, but selecting the best strain for a particular project has been a challenge.

SHEWANELLA

If the strain is put in an environment that contains high concentrations of uranium, that microbe is likely to acquire the genes that accept uranium from a nearby strain, in turn preventing uranium from spreading as the groundwater flows.

This adaptability of bacteria is remarkable.

SHEWANELLA

Konstantinidis’ team at Georgia Tech is currently investigating communities of these Shewanella strains in their natural environments to advance understanding of the influence of the environment on the evolution of the bacterial genome and identify the key genes in the genome that respond to specific environmental stimuli or conditions, such as the presence of heavy metals.

Part of genetic modification

Genetic Engineering of Escherichia coli for Enhanced Uptake and Bioaccumulation of Mercury

Weon Bae, Rajesh K. Mehra, Ashok Mulchandani, and Wilfred Chen

Department of Chemical and Environmental Engineering and Environmental Toxicology Program,

University of California, Riverside, California 92521 Received April 25, 2001; Accepted September 6,

2001.

Research paper

genetic engineering in Eastern cottonwood tree (Populus deltoides)

Researchers Richard Meagher, from UGA's Department of Genetics, and Scott Merkle, from UGA's Warnell School of Forestry, used genetic engineering to produce an Eastern cottonwood tree (Populus deltoides) capable of cleaning up contaminated soil through a process known as phytoremediation.

In a study published in 2007, Meagher and Scott describe their engineering of cottonwoods to extract toxic mercury from the soil.

The trees then release the vapor into the atmosphere, where it is diluted to harmless levels.

Genetic modifications in plants

Major successes have also been achieved in producing the biodegradable plastic polymer polyhydroxybutyrate (PHB) in Arabidopsis.

Nylon and polyester-like compounds are not far behind!!!

Plants have a remarkable ability to extract and concentrate elements and compounds from air, water, and soil.

Phytoremediation

Bacterial mercuric ion reductase, MerA, is effective in catalyzing the reduction of mercuric ion, to elemental mercury by using NADPH as an electron donor .

MerA is a soluble, NADPH-dependent, FAD-containing, disulfide oxidoreductase.

Rugh et al. began this fascinating research project with the goal of increasing mercury resistance and volatilization in plants expressing merA.

Mercury breathing plants

The difficulty was that the bacterial merA gene was heavily skewed toward GC-rich sequences, contained no plant translation signals.

To ensure translation in plants, the authors built a synthetic gene, merApe9, with a lowered GC composition and few rare codons and CpG dinucleotide.

What is the difficulty??

In addition, the 5' region immediately upstream of the initiator ATG codon was replaced with consensus plant and Escherichia coli translation signals.

The modified merApe9 encoded a functional mercuric ion reductase in transformed E. coli.

Agrobacterium tumefaciens-assisted transformation was used to introduce merApe9 into the recipient plant, Arabidopsis thaliana.

Mercury breathing plants

Analysis of T2 and later generation plants showed greater resistance to germination and growth on medium containing HgCl2 concentrations of 25-100 µM.

These levels were toxic to most plant species but not to the transformed Arabidopsis.

Rapid evolution of mercury vapor by relative to control plants confirmed resistance was due to mercury reduction.

Plants and bacteria expressing merApe9 -more resistant to toxic levels of Au2+ also.

Result

The efficiency of phytoremediation can be improved by expressing high-affinity, high selectivity metal-binding peptides interand extracellularly.

Well-known metal binding proteins include metallothioneins, metalloenzymes; metal-activated enzymes; and various metal storage, carrier, and channel proteins.

They are widely distributed in yeast and in lower and higher plants.

Future works

Metal binding domains from newly discovered or already known proteins may be incorporated in synthetic genes encoding low molecular weight peptides, which can be expressed in plant roots, the vascular system, and, if necessary, shoots.

Future works

In addition, sequential rounds of randomized mutagenesis followed by selection under increasing metal binding stringency can be used to modify and improve metal binding efficiency and selectivity of known and newly identified metal binding proteins.

Future works

Genes that encode such high-affinity transporters may be used to engineer plants capable of enhanced accumulation of particular metals.

Future works

This solution in a non-hazardous/non-corrosive remediation agent.

It is 100% green chemistry, an enzyme that is non-hazardous, non-corrosive and non-toxic and is biodegradable. 

It neutralizes soil toxicity to support healthy plant growth and makes it ideal for open water applications

A recent patented product-ECOBIOTIXRemedy of all!!!

This enzyme is now being used by the U.S. Supreme Court to rid the toxin and smell within the lines of the sewers. 

It has also been used to clean off contaminated equipment from the Iraq war.

LETS CHECK OUT THIS GOD THING!!!

A recent patented product-ECOBIOTIXRemedy of all!!!

VIDEO OF ECOBIOTIX

"What's the use of a fine house if you haven't got a

tolerable planet to put it on?"- Henry David Thoreau

LET’S TAKE A SERIOUS ACTION MY FRIENDS TO SAVE OUR MOTHER

EARTH!!!

GREENPEACE ACTION

ARTICLES FOR PHYTOREMEDIATION

Fox, B. & Walsh, C. T. (1982) J. Biol.Chem. 253, 4341-4088.

Lehman, N. & Joyce, G. F. (1993) Nature (London) 361, 182-185.

Kumar, P. B. A. N., Dushenkov, V., Motto, H. & Raskin, I. (1995) Environ. Sci. Technol.29, 1232

Dushenkov, V., Kumar, P. B. A. N.,Motto, H. & Raskin, I. (1995) Environ.Sci. Technol. 29, 1239-1245.

REFERENCES

ARTICLES FOR BIOREMEDIATION BY MICROBES

Alonso A., Rojo, F. and Martinez, J.L. (1999) Environmental and clinical isolates of Pseudomonas aeruginosa show pathogenic and biodegradative properties irrespective of their origin. Environ. Microbiol., 1, 421–430. [PubMed]

Cases I. and de Lorenzo, V. (2001) The black cat/white cat principle of signal integration in bacterial promoters. EMBO J., 20, 1–11. [PMC free article] [PubMed]

Harvey S., Elashvili, I., Valdes, J.J., Kamely, D. and Chakrabarty, A.M. (1990) Enhanced removal of Exxon Valdez spilled oil from Alaskan gravel by a microbial surfactant. Biotechnology, 8, 228–230. [PubMed]

VIDEOS YOUTUBE

REFERENCES

THANK YOU ALL!!!