الفهرس 
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Abstract
Summary
Phycochemical screening was performed on some
euhalopic (Sargassum dentifolium, Padina boryana, Dictyota
dichotoma, Gelidium latifolium, Gracilaria dura,
Enteromorpha intestinalis and Codium tomentosum) and
oligohalopic (Cladophora glomerata, Spirogyra spp. and
Chara vulgaris) algae from Egypt to discriminate the main
differences between them as well as to determine whether
variation could be ascribed to differences between the two
main groups or specific for individual species. The main
experimental results could be briefly summarized in the
following:
Individual differences in the biochemical parameters were
recorded in all algal taxa under investigation.
Quantitative estimation of carbohydrates revealed irregular
fluctuation in all algal taxa under investigation despite of their
ecological habitat. Maximum value of total carbohydrate
content was recorded in Codium tomentosum. Meanwhile, the
lowest content was detected in chara vulgaris.
In addition, protein content varied considerably between algal
species. Gracilaria dura recorded the highest total protein
content while the lowest protein content was detected in
Padina boryana.
Summary
136
The amount of proline showed irregular differences according
to species. The highest content was estimated in Gelidium
latifolium. However, minimum value of proline was detected
in Spirogyra spp.
Quantitative differences in the number of polypeptide protein
bands of the oligohalopic and euhalopic algae are also
investigated in the current study. Scanning of the SDS-gel
revealed the presence of one common protein band (M.wt: 18
kDa) in all investigated algal taxa as well as the appearance of
three specific protein bands (M.wt: 125, 15 and 8 kDa) only in
the members of euhalopic algal group and finally the presence
of one specific protein band (M.wt: 240 kDa) only in all
members of oligohalopic algae.
Results obtained showed that, all algal taxa under
investigation are rich in antioxidants. Moreover, the measured
compounds with antioxidant properties varied markedly
among algal taxa despite of their habitat. Pronounced higher
activity of Spirogyra spp. in terms of total antioxidant
capacity and reducing power in this study was observed
concomitant with high contents of phenols, flavonoids and
glutathione.
Photosynthetic pigments of the investigated algal taxa
exhibited significant differences according to species and
characteristic in relation to divisions.
Summary
137
The overall observation revealed higher concentration of
chlorophyll b in the studied green algae, while chlorophyll a
was observed with higher values in both brown and green
algae. On the other hand, the highest carotenoid content was
detected in the brown algae.
Our investigation indicated also that, the mineral content
(sodium and potassium) of the euhalopic group has noticeable
greater values than those of oligohalopic members. Maximum
sodium and potassium in the current study was recorded in
red and brown algae.
Results also revealed that, mannitol was detected only in the
members of brown algae. Moreover, it is pronounced to note
here that glycerol contents of the euhalopic algae were higher
than those recorded in oligohalopic algal members.
Real-time Quantitative Polymerase Chain Reaction (qRTPCR)
analysis revealed that, the expression level of G3PDH
mRNA was significantly upregulated in euhalopic algal group
as compared to that of the oligohalopic algae.
The current work represented an important step toward
understanding the mechanisms involved in salinity adaptation
of the marine algae in their natural habitat.
Summary
138Finally, a scientific discussion was conducted to interpret our
results in the light of what was already known from previous
literatures.