genetically modified organisms in the field of bio-remediation

genetically modified organisms used for remediation of heavy metals, radioactive waste for bio-remediation

1. COURSE WORK SEMINAR (II) ON GENETICALLY MODIFIED ORGANISMS FOR BIOREMEDIATION Presented by Swayam Prakash Nanda Regd No:1981002011 Environmental Science Department of chemistry

2. Contents Introduction Objective bioremediation strategies Factors affecting bioremediation Introduction of GMO Technique used for GMO Advantages and disadvantages Conclusion References

3. BIOREMEDIATION Bioremediation refers to the process of using microorganisms or plants to remove the environmental pollutants or prevent pollution. The removal of organic wastes by microbes for environmental clean-up is the essence of bioremediation. The other names used for bioremediation are biotreatment , bioreclamation and biorestoration . Xenobiotics broadly refer to the unnatural, foreign and synthetic chemicals such as pesticide, herbicide & other organic compounds. TYPES OF BIOREMEDIATION : 1. Biostimulation 2. Bioaugmentation 3. Intrinsic bioremediation

4. BIOREMEDIATION IS A TRIPLE-CORNERS PROCESS Pollutants Inorganic Inorganic Environments Organisms Soil Water Air Microorganisms Plants Enzymes

5. Objective of taking genetically modified organisms :- More efficient in bioremediation process. Survive in critical environmental conditions. Can be monitored easily. Beautification of a contaminated environment can be done by modified ornamental plants. Contaminants have less chance to enter food chain. Speed recovery of contaminated site is possible.

6. • Waste material is examined & certain microbes or plants are isolated based on their efficacy at digesting and converting the waste. • Indigenous or local bacteria is to be used. • The bacteria then go through several steps of cultures and process for performance testing. • The suitable bacteria are placed back in the waste environment. • They grow & thrive & in the process digest & convert the waste into Carbon dioxide & water. • The right temperature, nutrients, and food also must be present. • Conditions may be improved by adding “amendments.” How Does It Work?

7. ESSENTIAL FACTORS FOR MICROBIAL BIOREMEDIATION Factor Desired Conditions Microbial population Suitable kinds of organisms that can biodegrade all of the contaminants. Oxygen Enough to support aerobic biodegradation ( about 2% oxygen in the gas phase or 0.4 mg/litter in the soil water ). Water Soil moisture should be from 50–70% of the water holding capacity of the soil. Nutrients Nitrogen , phosphorus, sulphur , and other nutrients to support good microbial growth. Temperature Appropriate temperatures for microbial growth (10–40 ˚C ). pH Best range is from 6.5 to 7.5

8. GENETICALLY MODIFIED ORGANISM

9. The genetically engineered micro organism (GEMs)enhance the ability of degrading the contaminants. It is also said to be as a “ bioaugmentation ”. These organism is constructed by recombinant DNA technology. Some examples of GMOs action on various xenobiotics . GENETICALLY MODIFIED ORGANISM any organism whose genetic material has been altered using genetic engineering techniques . GMOs Xenobiotic P. olevorans Alkane Pseudomonas diminuta parathion P. cepacia 2, 4, 5-Trichlorophenol Alcaligenes sp 2, 4-dichlorophenoxy acetic acid Acinetobacter sp 4- chlorobenzene

10. Some examples of genetically modified organism The bacterium Deinococcus radiodurans ( the most radio resistant organism known ) has been modified to consume and digest toluene and ionic mercury from highly radioactive nuclear waste . Strains of Deinococcus radiodurans

11. mechanism of making superbug Prof. Ananda Mohan Chakraborty et al. ( 1979) developed and patented a “superbug” that degraded petroleum (camphor, octane, xylene, and naphthalene) by plasmid transfers. transformed Pseudomonas putida with plasmids derived from four different bacteria involved in hydrocarbon degradation.

12. Modified plants and genes for phytoremediation Gene Source Target plant Phenotype Reference SMT A. bisulcatus B. juncea Se volatization asb DMSe and DMDSe from media with 200 μM SeO 4 − increased 3 times (10% of Se evapotrated as DMDSe ) LeDuc et al., 2004 CAX2 A. thaliana N. tabacum 2.8, 2.5 and 1.3 times higher biomass when grown, respectively, on media with 3 μM Cd 2+ , 500 μM Mn 2+ and 150 μM Zn 2+ , then in roots 1.5 and 1.3 times higher Cd and Zn levels. Amount of metal accumulated per plant growing on media with 3 μM Cd 2+ , 500 μM Mn 2+ and 150 μM Zn 2+ was higher 3.4, 2.3 and 1.9times, respectively Korenkov et al., 2007b YCF1 S. cerevisiae A. thaliana 2.2 and 1.8 times higher biomass when grown on media with 60 μM Cd 2+ and 900 μM Pb 2+ , respectively. Shoots accumulated 1.5 times higher metal levels from media with 70 μM Cd 2+ or 750 μM Pb 2+ Song et al., 2003 gshI E. coli B. Juncea 2.1 times longer roots in media with 200 μM Cd 2+ . By 90% higher shoot Cd levels when grown in media with 50 μM Cd 2+ . When grown on polluted soilb , shoots showed 1.5, 2.0, 2.0 and 3.1 times higher Cd, Zn, Cu and Pb levels, respectively Zhu et al., 1999a Bennett et al., 2003 OAS-TL S. oleracea N. tabacum On medium with 300 μ M Cd 2+ : 2.5 times higher biomass, 2.8 times longer roots. On medium with 500 μ M Ni 2+ 1.3 times higher biomass, 4.2 times longer roots. On medium with 250 μ M SeO 4 − 1.5 times higher biomass, 1.8 times longer roots. Always higher chlorophyl content. When grown in media with 100 μ M Cd 2+ , the Cd levels 1.4 times increased in shoots and 4 times reduced in roots. Kawashima et al., 2004 TaPCS1 T. aestivum N. glauca 1.6 times longer roots on media with 800 μ M Pb 2+ or 50 μ M Cd 2+ . Shoots of transformed line NgTP1 accumulated from polluted soil. respectively, 6.0, 3.3, 4.8, 18.2 and 2.6 times more Pb , Cd, Zn, Cu and Ni. Gisbert et al., 2003 Martínez et al., 2006 merP Bacillus megaterium A. thaliana Capable of germination and growth on media with 12.5 μM Hg 2+ accumulating 5.35 μg Hg 2+ g of fresh seedling weight. Hsieh et al., 2009

13. Purpose of taking higher genetically modified plants :- For large scale remediation in contaminated site. High root coverage area causes high accumulation and degradation. Both ground water and soil contaminant can be removed. Useful by-product generation. Prevents soil erosion by large root coverage and direct enzymatic action on contaminant by the microorganism present in root zone. Flowering plants keep the polluted site pleasant. Landscape eco-tourism.

14. Pteris vittata Liriodendron tulipifera Eichhornia crassipes Brassica juncea Cannabis sativa Alyssum bertolonii Some higher plants ( genetically modified)

15. Advantages More efficient than traditional methods of bioremediation. Over all efficiency of G.M. plants will be increases. Easy and enhanced method of cleaning environmental contaminant. Multiple contaminant may be degraded by GMO. The groundwater and soil can be treated at the same time by using in-situ bioremediation by using higher genetically modified plants.

16. Disadvantages Risk of getting harmful organism or weed if the experiment goes wrong. May not be economically efficient. Upsetting the ecosystem. Ethical issues. Disrupting crop yield (may be ).

17. Conclusion Recovery of a contaminated medium by using living organisms. Approach to enhance the degrading capability. Application in all types of contaminated fields. Effective process for bioremediation. Genetic engineered micro-organisms are developed for environmental clean-up process. Eco-friendly technology . Further research going on to degrade plastic waste which is a major problem for both aquatic and terrestrial environment world wide.

18. References:- Chakrabarty , AM; Mylroie , JR; Friello , DA; Vacca , JG (1975). "Transformation of Pseudomonas putida and Escherichia coli with plasmid-linked drug-resistance factor DNA". Proceedings of the National Academy of Sciences of the United States of America 72 (9): 3647–51. Brar SK, Verma M, Surampalli RY, MisraK , Tyagi RD, Meunier N and Blais JF , “ Bioremediation of hazardous wastes: are view‖, Pract Periodical Hazard, Toxic Radioactive Waste Management”. 10:59-72, 2006 . Urgun-Demirtas , M., Stark, B., & Pagilla , K. (2006). Use of Genetically Engineered Microorganisms (GEMs) for the Bioremediation of Contaminants. Critical Reviews in Biotechnology, 26(3), 145–164 . Bioremediation, its Applications to Contaminated Sites in India , Ministry of Environment & Forests. Text book of Biotechnology- U.sathyanarayana .