الفهرس 
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Abstract
The present study aimed to screen antifungal activity of
methanol, ethanol, chloroform, cold and hot water extracts of
the four selected marine algae, green algae (Ulva lactuca),
brown algae (Sargassum denticulatum, Hormophysa triquetra)
and red algae (Hypnea cornuta) and one blue-green algae from
freshwater (Spirulina platensis) against four pathogenic fungi
(Candida albicans, Candida tropicalis, Candida krousei and
Candida glabrata).
For this study the following steps were done:
Sampling program:
A-Fresh water alga (Spirulina platensis):
The tested blue green alga Spirulina platensis obtained
from Stock at Hydrobiology Lab, Qanater Khayria, Qalubia,
Egypt.
B- Marine algae:
The seaweeds collected seasonally for one year
(September 2013 to August 2014) from the intertidal zone of
the Gulf of Suez. Three algal samples: Ulva lactuca
(Chlorophyceae) during spring, Sargassum denticulatum
(Phaeophyceae) during autumn and Hypnea cornuta
(Rhodophyceae) during winter were taken from Site I (Ras El-
Adabiya ) and one algal sample from Site II (Ras Sedr)
Hormophysa triquetra (Phaeophyceae) during summer.Physico-chemical parameters for sea water samples:
Temperature: Water temperature values ranged
between 15 °C and 26°C during winter and spring,
respectively at site I, while its value was 30 °C during summer
at site II.
pH: pH values were always on the alkaline side
recorded the highest value of 8.7 during winter and the lowest
value of 7.8 during spring at site I, while its value was 8 during
summer at site II.
Salinity: Water salinity values ranged between 38% and
40.5 % during winter and spring, respectively at site I, while its
value was 42 % during summer at site II.
Dissolved Oxygen (DO): Dissolved oxygen values
ranged between 6.2 mg/L during spring and 17.5 mg/L during
autumn at site I, while its value was 6 mg/L during summer at
site II.
Nitrate (NO3): The highest value of NO3 was 4.6 mg/L
during winter and the lowest value of 0.03 mg/L was during
autumn at site I, while its value was 0.021 mg/L during summer
at site II.
Nitrite (NO2): The highest value of NO2 was 0.032
mg/L during spring and the lowest value of 0.004 mg/L was
during autumn at site I, while its value was 0.006 mg/L during
summer at site II.Ammonium (NH4):
The highest value of NH4 was 0.3 mg/L during spring
and the lowest value of 0.11 mg/L was during autumn at site I,
while its value was 0.019 mg/L during summer at site II.
Phosphate (PO4): The highest value of PO4 was 0.015
mg/L during spring, while the lowest value of 0.005 mg/L was
during autumn at site I. The value of 0.005 mg/L was recorded
during summer at site II.
Biological parameter (photosynthetic pigments):
Chlorophyll-a content: The highest concentration of
chlorophyll a was 12.9 μg/L in Ulva lactuca, while the lowest
value of 6.9 μg/L was in Hypnea cornuta
Chlorophyll-b content: The highest concentration of
chlorophyll-b was 24.9 μg/Lin Ulva lactuca, while the lowest
value of 9.1μg/L was in Sargassum denticulatum
Chlorophyll-c content: The highest concentration of
chlorophyll-c was 12.3 μg/L in Sargassum denticulatum, while
the lowest value of 11.3μg/L was in Hormophysa triquetra.
Carotenoids content: The highest concentration of
carotenoids was 4.41 μg/L in Ulva lactuca., while the lowest
value of 2.7 μg/L was in Spirulina platensis.Quantitative determination of total Proteins,
Carbohydrates, Lipids and Phenols (%):
Total Proteins: the highest total proteins value of
30.2% was recorded for Spirulina platensis, while the lowest
value of 11% was recorded for Hormophysa triquetra.
Total Carbohydrates: the highest total carbohydraes
value of 24.9% was recorded for Ulva lactuca, while the
lowest value 6.6% was recorded for Sargassum denticulatum.
Total Lipids: the highest total lipids value of 41.1%
was recorded for Ulva lactuca, while the lowest value of 6.2%
was recorded for Hormophysa triqetra.
Total Phenols: the highest total phynols value of 15.3%
was recorded for Sargassum denticulatum, while the lowest
value of 4.2% was recorded for Hypnea cornuta.
Antifungal activity for selected algal species against the
tested oral Candida species:
In the present results showed that the Ulva lactuca
(Chlorophyta) methanol extract was the most active against all
the tested oral Candida species (C. albicans, C. tropicalis, C.
krusei and C. glabrata) with inhibition zones of 45.00±2.4,
35.00±0, 32.00±2.1 and 30.00±2.5 mm, respectively, followed
by Sargassum denticulatum (Phaeophyta), Hypnea cornuta
(Rhodophyta) and Spirulina platensis (Cyanophyta), where
they had similar effects against the tested oral Candida spp.Determination minimum inhibitory concentrations (MIC) and
minimum fungicidal concentrations (MFC):
The present study showed that the MIC/ MFC values for
the most effective algal crude extracts were 62.5 /125 mg/ml
against most of the tested oral Candida species.
Determination of the percentage inhibition of diameter
growth (PIDG):
The determination of the PIDG for all the tested oral
Candida spp. shown that Ulva lactuca methanol extract
exhibited a higher inhibition ability compared to chlorhexidine
(a positive control used in this study which is a common
antimicrobial agents in a commercialized oral rinses).
The effect of most potent algal crude extract on
micromorphology of the tested oral Candida spp. using
different MIC doses:
The Ulva lactuca methanol crude extract with different
concentrations of 1xMIC, 2xMIC and 4xMIC , showed effect
on the formation of the morphological structures of C.
albicans, C. tropicalis and C. krusei. This effect depends on
the concentration of Ulva lactuca methanol extract. The
highest extract concentration has the highest ability to inhibit
the morphological forms (blastoconidia, pseudohypha and
chlamydoconidia).Detection of the active compounds found in algal extracts
using Gas chromatography-Mass Spectrometry (GC-MS):
In the present investigation the GC/MS analysis of
Spirulina platensis, Ulva lactuca, Sargassum denticulatum,
Hormophysa triquetra and Hypnea cornuta methanol extracts
showed a mixture of various components, most notably
phenols and fatty acids were common. Biologically the active
compound have its role as antimicrobial.