Download Table No. 3-Antibacterial activities of seaweeds

Sanction No. F. No. 47-629/2008 (WRO) dated 11th February 2009
A Final Report
On
Minor Research Project
Entitled
“ALLELOPATHIC EFFECTS OF SELECTED
SEAWEEDS FROM COAST OF MAHARASHTRA
ON CERTAIN FUNGI AND BACTERIA’’
Submitted to
UNIVERSITY GRANTS COMMISSION
WESTERN REGIONAL OFFICE
GANESHKHIND, PUNE-7.
By
Dr. MOHITE ANGAD KERBA
M. Sc., M. Phil, Ph. D.
Head
Department of Botany
R. B. NARAYANRAO BORAWAKE COLLEGE, SHRIRAMPUR
DIST.- AHMEDNAGAR (M.S.) INDIA.
Executive Summary
The use of algae by human being dates back to 10,500 to 300 BC in Japan.
Thus from the time immemorial the Seaweeds i.e. macroscopic marine algae have
been closely associated with human life and are being exhaustively used in
numerous ways as a source of food, feed, fertilizer, medicine and chiefly for
economically
important
phycocolloids
(Chapman,
1970).The
diversity
and
abundance of algae have made them prime material for human use (Waaland,
1981). Maharashtra state has very long coastal line supporting several important
seaweeds.
Seaweeds are considered as best source of bioactive compounds with
cystostatic, antiviral, antihelminthic, antifungal and antibacterial activities. They have
also been used to treat some diseases like cancer, arthritis etc. They have been
screened extensively to isolate life saving drugs or biologically active substances all
over the world. Marine algal sources are receiving much attention mainly because of
the contents of functional ingredients such as polyunsaturated acids, carotenoid
pigments, sulphated polysaccharide and sterol. Among different compounds with
functional properties, anti oxidants and antibacterials are mostly and widely studied.
Aims and ObjectivesThe literature survey indicates that large numbers of seaweeds from
Maharashtra coast are not exploited for their potential antimicrobial activities by
earlier workers. Therefore, the present attempt was made to test allelopathic effects
of selected seaweeds from coast of Maharashtra on certain fungi and bacteria with
following objectives.
1. Collection of selected seaweeds from coast of Maharashtra and their
identification.
2. To obtain different types of seaweed extracts using various solvents.
3. To study antimicrobial activities of these seaweed extracts on certain fungi.
4. To study antimicrobial activities of these seaweed extracts on certain bacteria.
5. To identify the most bioactive species from selected seaweed species.
The research problem started with work of Welch (1962) who carried out
preliminary survey on fungistatic properties of marine alga Lyngbya majuscula.
Extensive studies were carried out on antimicrobial activity of seaweeds throughout
world. But very few attempts were made on this aspect as far as seaweeds of
Maharashtra Coast are concerned.
Extracts were obtained by using completely dried seaweeds using various
solvents. Bacterial bioassays were performed in sterilized petriplates containing
Mueller Hinton medium. Antifungal activities were studied by sterilized plate’s field by
sterilized modified PDA medium (Bambode and Shukla, 1973).
Antifungal activities:All the seven seaweed extracts prepared by using Ethanol were tested for
antifungal activity by well diffusion method against the fungus Aspergillus niger. The
results obtained were shown in Table No. 2 and Photo plate no. 1.
Sr.
No.
Name of Seaweed
Zone of Inhibition in mm
Plate I
PlatII
Plate III
Mean
1
Ulva fasciata
16.50
16.00
17.00
16.50
2
Ulva lactuca
12.00
12.00
12.50
12.17
3
Enteromorpha intestinalis 10.00
9.50
10.00
9.84
4
Sargassum wightii
14.80
14.50
15.00
14.77
5
Dictyota dichotoma
7.00
7.50
7.00
7.16
6
Hypnea valentie
6.00
6.00
6.50
6.16
7
Gracillaria corticata,
9.00
10.00
9.50
9.50
8
Control
00
00
00
00
Table No. 2- Antifungal activities of seaweeds against Aspergillus niger
The average range of zone of inhibition varies from minimum of 6.16 mm by
red seaweed Hypnea valentine to a maximum of 16.50 mm by green seaweed Ulva
fasciata. Two seaweeds, Sargassum wightii and Ulva lactuca also showed better
antifungal activity with 14.77 mm and 12.17 mm zone of inhibition against the test
fungus. All remaining seaweed extracts exhibited comparatively less antifungal
activity but still very well as compared to control. The results obtained during present
studies are in accordance with some earlier reports but also deviates from that of few
earlier reports
Antibacterial activities:Extracts of all the seven seaweed were prepared by using Ethanol and tested
for antibacterial activity by well diffusion method against the two bacteria,
Escherichia coli and Staphylococcus aureus. The results obtained were shown in
Table Nos. 3 and 4 as well as Photo plate nos. 2 and 3, respectively.
Sr.
No.
Name of Seaweed
Zone of Inhibition in mm
Plate I
Plate II
Plate III
Mean
1
Ulva fasciata
17.00
18 .00
17.50
17.5
2
Ulva lactuca
8.50
8.50
8.00
8.16
3
Enteromorpha intestinalis
5.00
5.50
5.00
5.17
4
Sargassum wightii
11.00
10.50
10.00
10.50
5
Dictyota dichotoma
9.00
9.00
9.00
9.00
6
Hypnea valentie
11.00
1100
11.50
11.17
7
Gracillaria corticata,
6.00
6.00
6.00
6.00
8
Control
00
00
00
00
Table No. 3-Antibacterial activities of seaweeds against Escherichia coli
Values from the observation tables clearly indicate that almost all ethanolic
seaweed extract had very good zone. The average range of zone of inhibition
against Escherichia coli varies from minimum of 5.17 mm by brown seaweed
Enteromorpha intestinalis to a maximum of 17.50 mm by green seaweed Ulva
fasciata. All remaining seaweed extracts showed comparatively less antibacterial
activity even though good and promising as compared to the control.
Sr.
No.
Name of Seaweed
Zone of Inhibition in mm
Plate I
PlateII
Plate III
Mean
1
Ulva fasciata
21.0
20.0
20.0
20.33
2
Ulva lactuca
9.00
9.50
9.00
9.16
3
Enteromorpha intestinalis
8.5
8.5
8.0
8.16
4
Sargassum wightii
11.00
11.5
11.5
11.33
5
Dictyota dichotoma
4.50
4.00
4.00
4.16
6
Hypnea valentie
9.00
9.50
9.00
9.16
7
Gracillaria corticata,
6.50
6.50
6.00
6.16
8
Control
00
00
00
00
Table No.4- Antibacterial activities of seaweeds against Staphylococcus aureus
Similarly all seven seaweed extracts showed most promising results against
the bacterium, Staphylococcus aureus. The obtained range of zone of inhibition is
4.16 mm to 20.33 mm. The minimum zone of inhibition is recorded in a red seaweed
Dictyota dichotoma and maximum zone of inhibition is by Ulva fasciata.
The results obtained for antibacterial activities during present studies are in
accordance with some earlier recent reports by Tuney et al. (2006), Radhika et al.
(2012) and Seenivasan et al. (2012), but also deviates from that of few earlier
reports. This variation in antimicrobial activity might be due to the difference in use
of solvent for extraction and method of testing activity along with other biochemical
differences of that particular seaweed.
Conclusion
Seaweeds living in salty water of the ocean are recognized as a potential
source of bioactive natural products. They contain compounds ranging from sterols,
terpenoids to brominated phenolic, which show bioactivity against microorganisms
The activity of the seaweed’s ethanol extract will lead to a discovery of antimicrobial
agents derived from these natural products as an alternative or substitute to the
existing antibiotic. The research approaches used in this study was bioassays or
preliminary screening, which included the screening of antifungal and antibacterial
activity through well diffusion test. In the present study, many significant findings
were found whereby the ethanol extract exhibited the inhibitory activity against
fungus Aspergillus niger and bacteria Escherichia coli and Staphylococcus aureus.
Photo plate 1- Antifungal activity of selected Seaweeds against Aspergillus niger
P- Ulva fasciata, 1- Ulva lactuca, 2- Enteromorpha intestinalis, 3- Sargassum wightii, 4- Dictyota
dichotoma, 5- Hypnea valentine, 6- Gracillaria corticata,N- Control
Photo plate 2- Antibacterial activity of selected Seaweeds
P- Ulva fasciata, 1- Ulva lactuca, 2- Enteromorpha intestinalis, 3- Sargassum wightii, 4- Dictyota
dichotoma, 5- Hypnea valentine, 6- Gracillaria corticata,N- Control
Photo plate 3-Antibacterial activity of selected Seaweeds
P- Ulva fasciata, 1- Ulva lactuca, 2- Enteromorpha intestinalis, 3- Sargassum wightii, 4- Dictyota
dichotoma, 5- Hypnea valentine, 6- Gracillaria corticata,N- Control