Shalin Saleem; Dr.Sanil Kumar, K V(Cochin University Of Science And Technology, October 16, 2012)
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Abstract:
Satellite remote sensing is being effectively used in monitoring the ocean
surface and its overlying atmosphere. Technical growth in the field of satellite sensors
has made satellite measurement an inevitable part of oceanographic and atmospheric
research. Among the ocean observing sensors, ocean colour sensors make use of
visible band of electromagnetic spectrum (shorter wavelength). The use of shorter
wavelength ensures fine spatial resolution of these parameters to depict oceanographic
and atmospheric characteristics of any region having significant spaio-temporal
variability.
Off the southwest coast of India is such an area showing very significant
spatio-temporal oceanographic and atmospheric variability due to the seasonally
reversing surface winds and currents. Consequently, the region is enriched with
features like upwelling, sinking, eddies, fronts, etc. Among them, upwelling brings
nutrient-rich waters from subsurface layers to surface layers. During this process
primary production enhances, which is measured in ocean colour sensors as high
values of Chl a. Vertical attenuation depth of incident solar radiation (Kd) and Aerosol
Optical Depth (AOD) are another two parameters provided by ocean colour sensors.
Kd is also susceptible to undergo significant seasonal variability due to the changes in
the content of Chl a in the water column. Moreover, Kd is affected by sediment
transport in the upper layers as the region experiences land drainage resulting from
copious rainfall. The wide range of variability of wind speed and direction may also
influence the aerosol source / transport and consequently AOD.
The present doctoral thesis concentrates on the utility of Chl a, Kd and AODprovided by satellite ocean colour sensors to understand oceanographic and
atmospheric variability off the southwest coast of India. The thesis is divided into six
Chapters with further subdivisions
Description:
faculty
of Marine Sciences,Cochin University of Science and Technology
Newby, Joseph; Dr.Saramma, A V(Cochin University of Science and Technology, December 28, 2002)
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Abstract:
Aquatic ecosystem in the south west coast of India is noted for its diversity of
habitats. Very often these environments turn bluegreen when the bloom of
bluegreen algae (cyanobacteria) appear consequent to eutrophication. This
phenomenon occursin these habitats one after the other or simultaneously. This
conspicuousness make one curious enough to know more about these nature’s gift
bestowed upon mankind. While persuing the literature on the magnificent flora) it
is understood that it may provide food fertilizer, chemicals and bioactive
substances. These bioactive substances are likely to be involved in regulating
natural populations and are potentially useful as biochemical tools and as
herbicidal or biocontrol agents. The role of cyanobacteria in the aquatic food
chain and contribution in abatement of heavy metals from the natural
environment are well documented. Considering the manifold utilization of the flora and their significance in the food chain, the present investigation has been undertaken
Description:
Department of Marine
Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology
Preetha, K; Dr. Gopalakrishna Pillai, N(Cochin University of Science and Technology, December , 1994)
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Abstract:
The thesis on the"Benthic ecology of selected prawn culture fields and ponds near Cochin” was taken up with a view to provide information on the qualitative and quantitative distribution of benthos and their relationships to prawnproduction of different culture ecosystems and to the physico-chemical parameters influencing their production. A two-year observation was carried out in nine selected prawn culture systems including perennial ponds (stations 1 to 4) seasonal fields (stations 5 to 7) and contiguous canals (stations 8 and 9) during December 1988 to November 1989. All macro- and meiobenthic organisms contributing to the faua were identified and their abundance, distribution, diversity, biomass and trophic relationships between benthos and prawns were studied. The environmental variables studied were temperature pH, salinity, dissolved oxygen, alkalinity, nitrite-nitrogen, nitrate-nitrogen, amonianitrogen, phosphate and silicate of bottom water and organic carbon and texture of the soil
The thesis is presented in 4 Chapters. Chapter I presents an’ INTRODUCTION to the topic of study and a review of relevant works to bring an awareness to the present status of research in benthos and benthic ecology. Chapter 11, MATERIALS AND MTHODS, includes the techniques of sampling, preservation of samples and methods of analyses of various physico-chemical factors and area covered under the study is also given in this chapter. Chapter III, HYDROGRAPHY deals with the results of investigation and discussion onthe physico-chemical parameters of water and Chapter IV, SEDIMENT covers the sedimentoloical characteristics of the different culture systems followed by a detailed discussion. Chapter V, BOTTOM FAUNA presents an account on the various aspects of benthos and benthic ecology and the details of prawn production. A discussion on the overall assessment of interrelations between abiotic and biotic factors is given in Chapter VI, DISCUSSION. A critical evaluation of the implication of benthic production on prawn production under culture conditions and trophic relationships are also included in this chapter. An executive SUMMARY of the observations made during this study is presented in the final section of the thesis .
Murukesh, Nebula; Dr. Chandramohanakumar, N(April 21, 2016)
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Abstract:
Mangroves are specialised ecosystems developed along estuarine sea
coasts and river mouths in tropical and subtropical regions of the world,
mainly in the intertidal zone. Hence, the ecosystem and its biological
components is under the influence of both marine and freshwater
conditions and has developed a set of physiological adaptations to
overcome problems of anoxia, salinity and frequent tidal inundations. This
has led to the assemblage of a wide variety of plant and animal species of
special adaptations suited to the ecosystem.
The path of photosynthesis in mangroves is different from other
glycophytes. There are modifications or alterations in other physiological
processes such as carbohydrate metabolism or polyphenol synthesis. As
they survive under extreme conditions of salinity, temperature, tides and
anoxic soil conditions they may have chemical compounds, which protect
them from these destructive elements. Mangroves are necessarily tolerant
of high salt levels and have mechanisms to take up water despite strong
osmotic potentials. Some also take up salts, but excrete them through
specialised glands in the leaves. Others transfer salts into senescent leaves
or store them in the bark or the wood. Still others simply become
increasingly conservative in their water use as water salinity increases. A
usual transportation or biosynthetic path as other plants cannot be expected
in mangrove plants.
In India, the states like West Bengal, Orissa, Andhra Pradesh, Tamil
Nadu, Andaman and Nicobar Islands, Kerala, Goa, Maharashtra, and
Gujarat occupy vast area of mangroves. Kerala has only 6 km2 total
mangrove area with Rhizophora apiculata, Rhizophora mucronata,
Bruguiera gymnorrhiza, Bruguiera cylindrica, Avicennia officinalis,
Sonneratia caseolaris, Sonneratia apetala and Kandelia candal, as the
important species present, most of which belong to the family
Rhizophoraceae.Rhizophoraceae mangroves are ranked as “major elements of
mangroves” as they give the real shape of this unique and interesting
ecosystem and these mangrove species most productive and typical
characteristic ecosystem of World renowned. It was found that the
Rhizophoraceae mangrove extracts exhibit several bioactive properties.
Various parts of these mangroves are used in ethnomedicinal practices.
Even though extracts from these mangroves possess therapeutic activity
against humans, animal and plant pathogens, the specific metabolites
responsible for these bioactivities remains to be elucidated. Various parts of
these mangroves are used in ethnomedicinal practices. There is a gap of
information towards the chemistry of Rhizophoraceae mangroves from
Kerala.
Thorough phytochemical investigation can achieve the validity of
ethnomedicines as well as apply the use of mangrove plants in the
development of new drugs. Such studies can pave a firm base for their use
in biomarker and chemotaxonomic studies as well as for the better
management of the existing mangrove ecosystem. In this study, the various
chemical parameters including minerals, biochemical components,
bioactive and biomarker molecules were used to classify and assess the
possible potentials of the mangrove plants of the true mangrove family
Rhizophoraceae from Kochi.
Chitra Som, R S; Dr.Radhakrishnan,C K(Cochin University of Science and Technology, November , 2010)
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Abstract:
The oceans have proved to be an interminable source of new and
effective drugs. Innumerable studies have proved that specific compounds
isolated from marine organisms have great nutritional and pharmaceutical
value. Polyunsaturated fattyacids (PUFA) in general are known for their
dietary benefits in preventing and curing several critical ailments including
Coronary heart disease (CHD) and cancers of various kinds.
Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) are two
PUFA which are entirely marine in origin – and small Clupeoid fishes like
sardines are known to be excellent sources of these two compounds. In this
study, we selected two widely available Sardine species in the west coast,
Sardinella longiceps and Sardinella fimbriata, for a comparative analysis of
their bioactive properties. Both these sardines are known to be rich in EPA
and DHA, however considerable seasonal variation in its PUFA content was
expected and these variations studied. An extraction procedure to isolate
PUFA at high purity levels was identified and the extracts obtained thus were
studied for anti-bacterial, anti-diabetic and anti-cancerous properties.Samples of both the sardines were collected from landing centre,
measured and their gut content analysed in four different months of the year
– viz. June, September, December and March. The fish samples were
analyzed for fattyacid using FAME method using gas chromatography to
identify the full range of fattyacids and their respective concentration in each
of the samples. The fattyacids were expressed in mg/g meat and later
converted to percentage values against total fatty acids and total PUFA
content. Fattyacids during winter season (Dec-Mar) were found to be
generally higher than spawning season (June-Sept). PUFA dominated the profiles of both species and average PUFA content was also higher during
winter. However, it was found that S. longiceps had proportionately higher
EPA as compared to S. fimbriata which was DHA rich. Percentage of EPA
and DHA also varied across months for both species – the spawning season
seemed to show higher EPA content in S. longiceps and higher DHA content
in S. fimbriata. Gut content analysis indicate that adult S. fimbriata is partial
to zooplanktons which are DHA rich while adult S. longiceps feed mainly on
EPA rich phytoplankton. Juveniles of both species, found mainly in winter,
had a gut content showing more mixed diet. This difference in the feeding
pattern reflect clearly in their PUFA profile – adult S. longiceps, which
dominate the catch during the spawn season, feeding mostly on
phytoplankton is concentrated with EPA while the juveniles which are found
mostly in the winter season has slightly less EPA proportion as compared to
adults. The same is true for S. fimbriata adults that are caught mostly in the
spawning season; being rich in DHA as they feed mainly on zooplankton
while the juveniles caught during winter season has a relatively lower
concentration of DHA in their total PUFA.Various extraction procedures are known to obtain PUFA from fish
oil. However, most of them do not give high purity and do not use materials
indicated as safe. PUFA extracts have to be edible and should not have
harmful substances for applying on mice and human subjects. Some PUFA
extraction procedures, though pure and non-toxic, might induce cis-trans
conversions during the extraction process. This conversion destroys the
benefits of PUFA and at times is harmful to human body. A method free from
these limitations has been standardized for this study. Gas Chromatography
was performed on the extracts thus made to ensure that it is substantially pure. EPA: DHA ratios for both samples were derived - for S. longiceps this
ratio was 3:2, while it was 3:8 for S. fimbriata.Eight common strains of gram positive and gram negative bacterial
strains were subjected to the PUFA extracts from both species dissolved in
acetone solution using Agar Well Diffusion method. The activity was studied
against an acetone control. At the end of incubation period, zones of
inhibition were measured to estimate the activity. Minimum inhibitory
concentration for each of the active combinations was calculated by keeping
p < 0.01 as significant. Four of the bacteria including multi-resistant
Staphylococcus aureus were shown to be inhibited by the fish extracts. It was
also found that the extracts from S. fimbriata were better than the one from S.
longiceps in annihilating harmful bacteria.Four groups of mice subjects were studied to evaluate the antidiabetic
properties of the PUFA extracts. Three groups were induced
diabetes by administration of alloxan tetra hydrate. One group without
diabetes was kept as control and another with diabetes was kept as diabetic
control. For two diabetic groups, a prescribed amount of fish extracts were
fed from each of the extracts. The biochemical parameters like serum
glucose, total cholesterol, LDL & HDL cholesterol, triglycerides, urea and
creatinine were sampled from all four groups at regular intervals of 7 days
for a period of 28 days. It was found that groups fed with fish extracts had
marked improvement in the levels of total LDL & HDL cholesterol,
triglycerides and creatinine. Groups fed with extracts from S. fimbriata seem
to have fared better as compared to S. longiceps. However, both groups did
not show any marked improvement in blood glucose levels or levels of urea.Cell lines of MCF-7 (Breast Cancer) and DU-145 (Prostate Cancer)
were used to analyse the cytotoxicity of the PUFA extracts. Both cell lines
were subjected to MTT Assay and later the plates were read using an ELISA
reader at a wavelength of 570nm. It was found that both extracts had
significant cytotoxic effects against both cell lines and a peak cytotoxicity of
85-90% was apparent. IC50 values were calculated from the graphs and it
was found that S. longiceps extracts had a slightly lower IC50 value indicating
that it is toxic even at a lower concentration as compared to extracts from
S. fimbriata.This study summarizes the bioactivity profile of PUFA extracts and
provides recommendation for dietary intake; fish based nutritional industry
and indigenous pharmaceutical industry. Possible future directions of this
study are also elaborated.
Description:
Department of Marine Biology, Microbiology and Biochemistry, Cochin
University of Science and Technology
Peter, Mani K; Dr. Babu, Philip(Cochin University of Science and Technology, November 5, 1998)
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Abstract:
The present work is focussed mainly on the utilization of this weed-biomass on a biochemical and biotechnological basis. Before designing scientific and systematic utilization of any given biomass, the detailed analysis of its chemical componets is essential. Hence, as the preliminary part of the experimental works, samples of Salvinia were analysed for its chemical constituents.Before designing scientific and systematic utilization of any given biomass, the detailed analysis of its chemical componets is essential .The composition of the substrate contributes much to the nutritive value of mushrooms. Hence, alterations in the nutritive value of mushrooms (in terms of total carbohydrates, proteins, lipids and minerals) in response to Salvinia as substrate were analyzed.Substrate after mushroom harvest (spent substrate) can be utilized for various purposes such as cattle feed, as a source of degradative enzymes, as a substrate for other mushrooms and as garden manure. But studies are limited with regard to the utilization of Pleurotus spent substrate as garden manure. So the value of spent substrate as an organic supplement and its multidimensional impacts on soil chemical status, soil microbial population dynamics and plant growth (Amhurium andreanum) were carried out.Major findings of this work have got much relevance in designing measures to utilize different types of plant biomass, especially aquatic weeds, with the aid of a powerful biological tool, the lignocellulolytic fungus, Pleurorus
Description:
Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences
Francis, M S; Dr. Babu, Philip(Cochin University Of Science And Technology, October 26, 1995)
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Abstract:
The group cyanobacteria includes a large number of organisms
characterised by a low state of cellular organization. Their cells lack a
well defined nucleus. Cell division is by division of the protoplast by an
ingrowth of the septum. These organisms are characterised generally by a
blue green colouration of the cell, the chief pigments being chlorophyll-a,
carotenes, xanthophylls, C phycocyanin and C phycoerythrin. The product of
photosynthesis is glycogen. These organisms lack flagellate reproductive
bodies and there is a total lack of sexual reproduction. They are also
unique because of the presence of murein in the place of cellulose (cell
wall) and the absence of chloroplast, mitochondria and endoplasmic
reticulum. Just like bacteria some of them possess Plasmids and can fix
atmospheric nitrogen.
In the present study growth kinetics, heavy metal tolerance,
tolerance mechanisms, heavy metal intake, and antibacterial activity of
§ynechocystics salina Wislouch - a nanoplanktonic, euryhaline,
Cyanobacterium present in Cochin back waters has been carried out for the
potential biotechnological application of this organism. _§; salina occur
as small spherical cells of 3n diameter (sometimes in pairs) with bluish
green colour. The species is characterised by jerky movement of the cells
and is structrually similar to other cyanobacteria
Description:
Division of Marine Biology, Microbiology
and Biochemistry, School of Marine Sciences,Cochin University of Science and Technology