1) Isolation and cultivation of microalgae, collected during
episodes of mussel toxicity, red tides or mucilage production, in
order to identify the causative organism and to study the
environmental conditions which influence the proliferation and the
amount of toxins produced.
2) Study of the effect of microalgae exposition to pollutants
and evaluation of physiological responses.
3) Characterization of microalgae useful for phytoremediation,
biomass and biomolecules or biofuel production.
1) Phytoplankton organisms represent the first ring of the
trophic chain however some species can be harmful to the
environment or to human health; this is due to the following
problems: i) Hypoxic or anoxic events due to biomass decay after
blooms; ii) production of toxins affecting men or animals; iii)
foam accumulation causing damage to benthic organisms or to
economic activities (tourism and fishery). Phytoplankton species
involved in these events change from year to year as, for example,
in the Adriatic sea at the end of ‘80s there were mainly
Dinophysis species producing okadaic acid while since 1995
the prevailing toxic species was represented by the yessotoxin
producer Protoceratium reticulatum. New problems recently
arose such as: presence of new species producing yessotoxins,
presence of A. ostenfeldii which produces spirolids,
identification of domoic acid traces in mussels whose producer was
not yet identified, intense blooms of potentially icthyotoxic
algae, such as Fibrocapsa japonica, and appearance of algae
of the genus Ostreopsis which cause respiratory distress
in people walking on the beach. In collaboration with monitoring
and prevention agency and with chemist groups, a research activity
is performed aimed at the isolation and cultivation of the above
mentioned microalgae and at the study of the environmental
conditions, biotic and abiotic, which influence the
proliferation and the amount of toxins produced. Large culture
amounts are also performed in view of the structural
characterization and purification of relevant toxins.
2) Pollutants in the marine environment arise from different
sources giving rise to socio-economic damages (tourism and fishery)
and consequences to human health, due to ingestion of contaminated
seafood. Human health damage is the final and visible effect of a
long chain impacts on marine organisms (phytoplankton, mussels,
fishes). In fact, the toxic effect of pollutants is already
detectable at the primary producers level and is at this level that
attention must be focused in order to prevent ecosystem damages,
considering also that actual climate changes such as temperature
and CO2 increase could have synergic effects. The research activity
in this field is aimed at the study of the effect of pollutants
(heavy metals, antibiotics, herbicides, oil spill) on phytoplankton growth,
photosynthetic efficiency, nutrient uptake, cell chlorophyll and
carbon content. The study is performed by applying different
pollutant concentrations to phytoplankton cultures grown at
different temperatures; the results were also utilized for the
definition of mathematical formulations which will be used in
tri-dimensional numerical models of phytoplankton primary
production.
3) The industrial utilization of microalgae is promising in that
these organisms can be cultured by supplying waste water or waste
CO2 and the obtained biomass can be a source of many useful
compounds. The research is aimed at evaluating the use of
microalgae in water treatments with the purposes of collecting
biomass and utilizing it for biofuel production or for different
purposes. As a first step algal strains are selected on the basis
of their growth ability, biomass production and kind of compounds
produced by performing the experiments at optimal level of light,
temperature and with the addition of CO2. The selected strains are
then grown in waste water where the following parameters are
measured: growth rate, biomass production, nitrate, ammonium or
phosphate removal; the algae are also characterized in terms of
biochemical composition and photosynthetic efficiency. In
collaboration with different laboratories studies are also
performed on biomass transformation and collection.
Studies on growth and phytodepuration in pilot open ponds and
photobioreactors are performed.
