Bioremediation

1. BIOREMEDIATION OF
RADIOACTIVE WASTE
BY : SAURABH DUBEY
SHIVANGI AGARWAL
RITIKA GAUR
Under the guidance of Prof. Dr. Pammi Gauba
MINOR PROJECT - 2

2. • In the previous presentation we have discussed, how increasing amount of
radioactive waste can be harmful to humans and environment.
• Radioactive waste contains radioactive isotopes which emit ionizing radiation
which cause damage to living cells leading to mutation, cancer and other
health problems.
• The disposal of radioactive waste also possess significance challenge as it
requires careful management and monitoring to prevent accidental exposure.
• Bioremediation has been shown to be effective in removing or immobilizing
many types of radioactive isotopes
INTRODUCTION

3. • By bioremediation microorganisms can be used to break down certain
radioactive isotopes or to sequester them in a solid form that is less likely to
leach into the environment.
• There are different bioremediation approaches which is used to manage
nuclear active waste:
Biostimulation
Bioaugmentation
Phytoremidiation
Mycoremidiation
Bioaccumulation
Biosorption

4. • In one such method Biosorption has been shown to be a highly
effective method for removing radioactive contaminants.
• This effectiveness is due to the ability of the biological material
to selectively bind to the contaminants, often in a highly
efficient manner.
• The biological material used in biosorption can be regenerated
and re-used multiple times.
• To optimize the biosorption process, it may be necessary to
adjust various factors such as the concentration of the
biological material, the pH, temperature.

5. The mechanism of biosorption of nuclear active waste involves the
adsorption of radioactive ions onto the surface of the biosorbent
material through various mechanisms

6. CASE STUDY - 01
Keun-Young Lee, Sang-Hyo Lee, Ju Eun Lee, Seung-Yop Lee. “Biosorption of radioactive cesium from
contaminated water by microalgae Haematococcus pluvialis and Chlorella vulgaris” , Journal of
Environmental Management, Vol 233, 2019, Pg 83-88, https://doi.org/10.1016/j.jenvman.

7. 1.1 Introduction
 Biosorption can be defined as the ability of biological materials to accumulate heavy
metals from wastewater through metabolically mediated or physico-chemical pathways
of uptake.
 In the present study, the uptake properties of radioactive cesium by this unique
microalga Haematococcus pluvialis were evaluated with different cell conditions,
and its cesium-absorbing rate was compared with results by other microalgae,
Chlorella vulgaris and Anabaena sp.
 The effectiveness of 137Cs uptake is dependent on the specific cell condition of
even the same microalgal species.

9. 1.2 Materials and methods
A. MICROALGAE CULTURE
The unicellular green algae H. pluvialis CCAP 34/7 was obtained from CCAP and
cultured. In this culture, stress conditions of nitrogen-deprivation and high photon
flux density (300 μmolm−2 s−1) were imposed to the green cells to develop the
astaxanthin-accumulating red cells. Similarly for C. vulgaris and Anabaena sp.
B. 137 Cs UPTAKE EXPERIMENTS
The initial 137Cs source with 37 MBq/ml of radioactivity was serially diluted to the
target level of 3370 Bq/ml. Dense microalgal cells were inoculated into each of
the 100 ml sample solutions under neutral pH. The samples were shaken at 150
rpm then kept in a static condition for long-term 137Cs monitoring for 1year.
C. RADIOACTIVITY AND MICROSCOPIC
ANALYSIS
The samples were filtered through a 0.2 μm membrane and diluted by DI water.
These were analysed by a multi channel analyser for detection of gamma-ray at
661 keV for 1 h. The morphology analysis was done using spectrometer

10. 1.3
RESULTS

11. A. LIFE CYCLE OF H. pulvaris
The life cycle of H. pluvialis C consists of three types of distinguishable cellular
morphologies: flagellated cells, green cells (palmella) and red cysts (aplanospores). The
green palmella cells were then induced to accumulate astaxanthin, and form large red

12. B. 137 Cs uptake by H. pulvaris
●Fig. 1a shows the comparative kinetics
of 137Cs uptake by the H. pluvialis cells in
solution containing 370 Bq/ml Cs.
●The green cell showed the lowest uptake
yield of 137Cs. Also, the uptake yield was
not significantly increased when the cell
density was increased to the 107 cells/ml
●However, H. pluvialis red cell showed
better performance than the green cell,
even in the case of the one-hundred times
lower cell density.

13. C. 137 Cs uptake by different microalgae
● Anabaena sp. showed around 20%–
30% of 137Cs uptake yield.
●C. vulgaris is a green microalga with
considerable potential to remove
radionuclides, particularly radioactive
strontium
●Although the 137Cs uptake efficiency
of C. vulgaris reached around 90%, the
slow uptake rate resulted in a maximum
period of more than 10 days, even with a
higher cell density.

14. D. Reduced K/P ratio
●Cesium is reported to be absorbed
by plants and algal cells via
potassium transport channels
because its chemical characteristics
are similar to those of potassium.
●The reduction of molar ratio (K/P)
by H. pluvialis red cyst could be
direct evidence for the replacement
of potassium in the red cyst cell by
cesium via specific channels and
transporters.

15. ●In the protein expression profiles for H. pluvialis after
exposure to high light intensity, several subunits of the
potassium-transporting P-type ATPase were found in
red cyst cells.
●The expression level of the protein in red cyst cells
was 1.08×104 of Mowse score, which is a protein score
based on frequency of peptides occurrence.
●However, the protein did not identified from immature
green cells.
●Therefore, the 137Cs uptake acceleration by
astaxanthin-accumulating red cysts can be explained by
the replacement of cellular potassium.

17. E. Radioactivity analysis
●Fig besides, shows the long-term
(1 year) monitoring results of 137Cs
uptake by microalgae, both H.
pluvialis and C. vulgaris, and SEM
images after two comparative
periods of time.
●The maximum 137Cs uptake yield
continued for around 1 month,
whereas it stopped for longer
periods of 6 or 12 months.

18. Most of the cells collapsed (Fig. a,b ) and only around 40% of 137Cs remained in
H. pluvialis cell fragments. C. vulgaris cells contained about 50% of 137Cs after 12
months. The cellular collapse after the cesium uptake is mainly due to the fact
that dense microalgal cells were inoculated into cesium-contaminated solution
and this harsh culture condition was not proper for the cell survival and growth.

19. 1.4 CONCLUSION
●The comparative biosorption experiments were performed with other microalgae,
Chlorella vulgaris and Anabaena sp. and different H. pluvialis cell conditions.
●H. pluvialis red cyst outperformed the other cases by removing 95% of radioactive
cesium from the solution after 48 h, making the highest cesium biosorption ever
reported.
●Both H. pluvialis intermediate cells and C. vulgaris showed 90% uptake efficiency of
Cs with slow uptake rate.
●The cesium uptake acceleration by astaxanthin-inducing red cyst is correlated to the
cesium accumulation through the potassium transport channel.
● One-year biosorption monitoring showed that only 40% of 137Cs remained in
collapsed H. pluvialis cell fragments.

20. 1.5 FUTURE PROSPECTIVE
●More intensive investigations are required for selecting microalgal strains to
maximize biosorption performance in contaminated water including specific
radionuclides such as 137Cs with a high level of radiation and a long half-life.
●For the practical application as a remediation technology in the field, more detailed
and multilateral investigations need to be carried out in the future.
● Although this biosorption process could be effectively applied for the removal of
radionuclides from water, a novel method for the integrated biomass control is
required to completely collect and isolate the radioactive biomass from the
contaminated site.

21. CASE STUDY - 02
Reena, M.C. Manjhi, Rita Kumar, Anil Kumar, A.K. Arya. “BioRadBase : A database for bioremediation of
radioactive waste”. African Journal of Biotechnology Vol.11(35), pp 8718-8721. Published 2012 May 1. doi:
10.5897/AJB12.020

22. 2.1 Introduction
 BioRaDBase is the first database dedicated to micro-organisms which have been
explored or engineered to remediate radioactive waste from the environment.
 The database serves as a comprehensive knowledgebase to search bacteria and fungi
which have the ability to transform radioactive waste and can be a useful tool for the
development of new bio-remediation
 The information in database has been managed under five classes, that is, type of
radioactive waste, micro-organisms, genus listing, literature and waste management.
The entries are also linked to external databases such as NCBI , providing wide
background information.
 BioRaDBase can be accessed at http://biorad.igib.res.in.

23. 2.2 METHODOLOGY
A. DATASET AND DATABASE DEVELOPMENT:
 Reference literature was collected from published research work on NCBI Database
 Entries for section, type of radioactive waste and radioactive waste management were
collected from the Department of Energy (DOE, US) , International Commission on
Radiological Protection (ICRP) and environmental protection agency (EPA)
 The MySQL , a relational database management system was used for maintaining, storing
and retrieval of curated data.
B. DATABASE DESIGN AND FEATURES:
 The BioRaDBase web interface makes it feasible to access the available data by
categorizing them into five classes on a single page:

26. 2.3 RESULTS
 BioRaDBase is a platform that provides scattered and unorganized information
regarding radioactive waste remediation using micro-organisms in a
comprehensive way.
 The present database satisfies the condition of working as a knowledge device
that can motivates researchers to develop new microbial based technologies for
remediation of radioactive wastes.
 It can be extended further to keep pace with new scientific achievements in the
field.

27. [1]Gadd, G. M. ‘bioremediation of radioactive waste’’. Mycol. Res. 111, 3–49. doi:
10.1016/j.mycres.2006. 12.001
[2] Viti, C., Marchi, E., Decorosi, F., and Giovannetti, L. (2014).’’ Technology to
remediate radionuclides from enviorment’’. Rev. 38, 633–659. doi: 10.1111/1574-
6976.12051
[3] Tkavc R, Matrosova VY, Grichenko OE, et al. “Prospects for Fungal
Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome
Sequence of Rhodotorula taiwanensis MD1149”. Front Microbiol. 2018; 8:2528.
Published 2018 Jan 8. doi:10.3389/fmicb.2017.02528
Available : https://www.frontiersin.org/articles/10.3389/fmicb.2017.02528/full
REFERENCES

28. THANK
YOU !!!