ABSTRACT
The work on the study and evaluation of physicochemical and ecotoxicological characteristics
of green algae, particularly of the genus Ulva, carried out on the Algerian coast are few. Its
use is even less in the field of biomonitoring, which proves to be most urgent to apply on the
Algerian coastline which is increasingly faced with the stress of rapid growth of urbanization
and anthropization as well as various pollutions of multiple origins.
In view of that, the present work aims to determine the global chemical composition of the
Ulvasp algae collected on the west coast of Algiers at three sites (Ain Benian, Sidi Fredj, and
Ain Tagourait). Moreover, to examine its bioindicator power of pollution, through the
evaluation and estimation of bioactive compounds, namely polysaccharides as well as
polyphenols at the level of the three studied sites. To confirm the source of the variations of
these rates between the different sites, a physicochemical and bacteriological evaluation of the
coastal waters collected on each of the sites is carried out.
The results of the analysis of the vegetal matrix that is Ulvaspp indicate that it presents a very
high rate of mineral matter with a maximum value of ash of 33.85% of DM. On the other
hand, the lipid content is low, with an optimum value of 5.6% of DM.
It also contains an appreciable rate of total protein, whose value varies from one site to
another with a maximum of 16% of DM recorded at S1 Ain Benian, which is presumed to
present a place facing stress. This could advance a sign of the existence of possible bioactive
properties of these molecules. The contents of polysaccharides recorded for this alga are high.
With increasing rates according to the concentration in contamination of the sites, counting a
maximum value of 16,19% of MS. As well as a very important rate in polyphenols, their
content varies according to the sites. The most important value is recorded on S1 (Ain
Benian) and is estimated at 52.68 µg AgE/mg DM.
From the treatment of the seawater mineral matrix, it appears that the concentrations of total
and faecal coliforms, and faecal Streptococci are all in conformity with the Algerian
standards, according to the Algerian official water journal. Despite the non-significant
difference in the level of contamination of the sites, it was found that S2 (Sidi Fredj) is the
one that shows the highest values.
The results obtained from this work represent a good basis for a promising work that remains
to be completed.
The work on the study and evaluation of physicochemical and ecotoxicological characteristics
of green algae, particularly of the genus Ulva, carried out on the Algerian coast are few. Its
use is even less in the field of biomonitoring, which proves to be most urgent to apply on the
Algerian coastline which is increasingly faced with the stress of rapid growth of urbanization
and anthropization as well as various pollutions of multiple origins.
In view of that, the present work aims to determine the global chemical composition of the
Ulvasp algae collected on the west coast of Algiers at three sites (Ain Benian, Sidi Fredj, and
Ain Tagourait). Moreover, to examine its bioindicator power of pollution, through the
evaluation and estimation of bioactive compounds, namely polysaccharides as well as
polyphenols at the level of the three studied sites. To confirm the source of the variations of
these rates between the different sites, a physicochemical and bacteriological evaluation of the
coastal waters collected on each of the sites is carried out.
The results of the analysis of the vegetal matrix that is Ulvaspp indicate that it presents a very
high rate of mineral matter with a maximum value of ash of 33.85% of DM. On the other
hand, the lipid content is low, with an optimum value of 5.6% of DM.
It also contains an appreciable rate of total protein, whose value varies from one site to
another with a maximum of 16% of DM recorded at S1 Ain Benian, which is presumed to
present a place facing stress. This could advance a sign of the existence of possible bioactive
properties of these molecules. The contents of polysaccharides recorded for this alga are high.
With increasing rates according to the concentration in contamination of the sites, counting a
maximum value of 16,19% of MS. As well as a very important rate in polyphenols, their
content varies according to the sites. The most important value is recorded on S1 (Ain
Benian) and is estimated at 52.68 µg AgE/mg DM.
From the treatment of the seawater mineral matrix, it appears that the concentrations of total
and faecal coliforms, and faecal Streptococci are all in conformity with the Algerian
standards, according to the Algerian official water journal. Despite the non-significant
difference in the level of contamination of the sites, it was found that S2 (Sidi Fredj) is the
one that shows the highest values.
The results obtained from this work represent a good basis for a promising work that remains
to be completed.