Low and medium level waste generated by the
nuclear industry contain large number of radioactive isotopes of different
metals. The volume of this waste coupled with surfactants and interfering
radicals creates problem for conventional cleanup operations using synthetic
resins. In our recently concluded project funded by Department of Atomic
Energy, Govt of India, we have demonstrated that a non-conventional Biosorption
Techniques could be employed for the effective removal of radioisotope
from nuclear waste even in the presence of EDTA or nitrate. This technique
require the generation/ selection of suitable biomass using molecular biology
techniques which may be packed in glass or ss column for continuous operation.
Development
of whole cell bacterial biosensor for detection of residual drugs
In the
present project we aim to create a whole cell bacterial biosensor for antibiotic
detection and bioavailability testing by gene manipulation. Since promoter
sequences are modular and decide gene action, we intend to construct chimeric
plasmids in which heavy metal specific promoter sequence drive the expression
of reporter systems like GFP/Lux, and to transform selected bacterial strains
with these. When the transformed biosensor bacteria are exposed to samples
containing the target antibiotic, the antibiotic specific promoter will
trigger visual GFP/Lux expression by producing light directly proportional to
the concentration of the inducer antibiotic .
Development
of whole cell bacterial biosensor for detection of bioavailability and
concentration of metal pollutants.
Environmental pollution
by toxic compounds, particularly heavy metals and their radionuclides arise due
to various anthropogenic activities and are posing a major threat to both
humans and ecological balance. Quantification of heavy metal concentration for
pollution monitoring normally requires expensive equipments and often needs
substantial sample pretreatment. Also such methods cannot distinguish
pollutants that are biologically available and unavailable. Toxic heavy metals
in environment can only have an impact on living organisms to the extent they
are bioavailable. Unavailable forms are potentially, but not acutely toxic.
Hence a test of bioavailability is important in bioremediation, waste dumping,
waste treatment optimization, environmental impact assessment and in
prioritizing clean up tasks. Employing designer microorganisms for
environmental monitoring is a good alternative in this regard. When whole cell
biosensors are employed for this purpose, detection of the target compound is
possible in pico molar concentrations.
Development and charaterization of
exopolysaccharides from cyanobacteria for industrial applications
Many cyanobacteria known to
be able to synthesize outer most slimy layer composed of complex
polysaccharides and secrete polysaccharides into the culture medium during cell
growth. These released materials can be easily recovered from the culture
medium are of great interest in view of their possible uses in several
industrial applications. Although the rate of production is low when compared
to the heterotrophs, the complex nature and structurally diverse
polysaccharides from these organisms can be considered for the mass
production. Several strains of cyanobacterial based exopolysaccharides have
been used as bioemulsifyers, subsititure to agar-agar, secondary recovery of
petroleum, cosmetic material as skin-whitening agents etc.
Development of high
affinity biosorbents by surface display of metal binding proteins
The project is to
develop profit oriented economically feasible to implement by all metal
handling industries including DAE establishments for the treatment of low and
medium level metal containing effluents and nuclear wastes using enhanced
whole-cell biosorption technology. It is aimed at to proceed from the proof-of
concept to field testing stage. The development of such an efficient and
affordable technology for nuclear waste treatment is essential. In this
project we will develop a technology for the display of metal binding proteins
at the cell surface of cyanobacteria. The strains will be tested for immobilization
for the development of bioreactor to remove the radioactive and non-radioactive
metal from industrial effluents. The process parameters will be optimized for
scaling up. The proposed project may provide a cost effective, quick and more
metal binding capacity and it will find an essential alternative method for
online treatment in DAE and metal handling industries for safe discharge of
wastewater.
Isolation of bioactive compounds from
cyanobacteria for pharmaceutical applications
The cyanobacteria as a source for
pharmaceutically important compounds have been appreciated as early as 1500BC.
The current observation indicates that several strains were known to produce
potent anticancer, antibacterial, antifungal, antiviral compounds. The
cyanobacteria such as Microcystis, Nostoc, Anabaena and Oscillatoria
produces a variety of secondary metabolites. Cynobacteria could be a promising
group of organisms from which can be used to isolate novel, biochemically
active natural products which could find potential pharmaceutical applications.
Development of suitable matrix for cell
or enzyme immobilization
Immobilization of microbial cells and biocatalysts
such as enzymes is essential for industrial application. The conventional
immobilization techniques have limitations of low mechanical strength, leakage
of cells from matrix high cost, and cytocompatibility with polymeric matrices
etc. In the present project we develop novel biocompatible silica gel as
immobilization matrix and its characterization for the purpose of metal
accumulation using the immobilized cyanobacteria. The immobilized cells will
be evaluated for the mechanical stability and metal accumulation properties.
The method could be a cheaper and versatile technology for heavy
metal/radionuclides bioremediation.
