climate-change-global-envitox-2018-tracks

13 / 37

Page 57
Notes:
conferenceseries.com
Volume 2 Environment Pollution and Climate Change
ISSN: 2573-458X Climate Change 2018 &
Global ENVITOX 2018
October 04-06, 2018
October 04-06, 2018
London, UK
16th Annual Meeting on
Environmental Toxicology and Biological Systems
&
5th World Conference on Climate Change
JOINT EVENT
Among the wide range of microalgae species, which have been employed to develop biosensor technology, Chlamydomonas
reinhardtii was especially studied since it possess a number of features that suite perfectly the requirements of an early warning
environmental biosensor. It is a grass organism, easily cultivable having 8 hours doubling time and it can grow with or without
carbon source, besides, it is easily transformable and all 3 genomes are sequenced. Recent our efforts have focused on increasing
the stability and selectivity of PSII from microalgae for the detection of different subclasses of pollutants. These goals were
achieved by using the alga C. reinhardtii mutated at the D1 protein herbicide-binding site by site-directed mutagenesis. C.
reinhardtii was also modified introducing in the chloroplast antioxidant peptides, known in food able to reduce the content of
free radicals, thus lessening the photooxidative membrane damage. Measurements of in-vivo antioxidant activity showed that
mutant strains have improved their survival rate in the presence of singlet oxygen precursors, which highly exceeds the survival
rate of control algae, showing increased stability and sensitivity for biosensor applications.
Beyond these scientific achievements, nowadays the market needs highly specific and precise in situ measurement devices
able to collect and send the data in real-time for periods of months without maintenance under multi-stressors. These devices
demand more robust algal biomediators. Thus, the challenge is the preservation of the algal photosynthetic functionality when
integrated with electronic components or operated under fluctuating environmental conditions. To this end C. reinhardtii
mutants able to quench 1O2 and other ROS, were integrated into a newly developed miniature and portable electrochemical/
optical device, to measure and collect PSII data in real-time for long periods. Several photosynthetic pollutants spiked in real
samples were detected within 10 min in concentrations between ng/L-μg/L and the different algae species tested showed diverse
pesticide sensitivities.
Always towards to increase the biomediator performance, biomimetic peptides of the photosynthetic D1 binding niche of the
microalgae C. reinhardtii were developed, both by chemical and biological synthesis, as suggested by in silico analysis. Standing
out among the others, the biomimetic mutant peptide, D1pepS268C, bound to specific quantum dots, showed high ability
to mimic the microalgae in binding pesticides. Replacement of whole microalgae cells or their photosynthetic apparatus by
mimetic peptide improved the system in terms of stability.
This approach allowed also the integration of the biomediators with quantum dots and innovative stretchable printed electrodes-
based electrochemical biosensor as a wearable point-of-use screening tool for toxicity environmental analyses.
Biography
Maria Teresa Giardi has worked as the manager of research at the National Council of Research (IC-CNR) in Rome till 2015. She is now associated to CNR, working at the
company Biosensor srl as research director and CEO. Her background is in industrial chemistry with extensive experience in biochemistry and molecular biology; her main
interest is on photosynthetic protein stabilization and utilization in biosensors for real toxicity environmental monitoring. She is a supervisor-coordinator of several national
and international projects in the field of biosensors based on plants and microorganisms and of European Space Agency’s projects involving space flights of engineered
microorganisms to low orbit and to International Space