Prajith, K K; Dr.Madhusoodana,Kurup B(Cochin University of Science and Technology, December , 2011)
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Abstract:
In India a study conducted by CIFE and CIBA (1997), concluded that
shrimp farming does more good than harm and it is not eco-unfriendly
(Krishnan and Birthal, 2002). Upsurge in coastal aquaculture activity
induced by high profitability is reported to have caused adverse impacts on
coastal ecosystems and social environments (Parthasarathy and Nirmala,
2000). The crustacean farming sector has received criticism for excessive
use of formulated feed containing high protein, of which around 50% gets
accumulated at the pond bottom as unconsumed (Avnimelech, 1999; Hari
et al., 2004, 2006). The wasted feeds undergo the process of degradation
and results in the release of toxic metabolites to the culture system.
Reduction of protein in the feed, manipulation and utilisation of natural
food in the culture system are the remedy for the above problems. But
before reducing the feed protein, it should be confirmed that the feed with
reduced protein is not affecting the growth and health of the cultured
animal. In the present study, biofloc technology is identified as one of the
innovative technologies for ensuring the ecological and environmental
Sustainability and examines the compatibility of BFT for the sustainable
aquaculture of giant prawn, M. rosenbergii. This thesis starts with a general introduction (Chapter-1), a brief review of the most relevant literature (Chapter-2), results of various experiments (Chapter-3-6), summary (Chapter-7) and recommendations and future research perspectives in the field of biofloc based aquaculture (Chapter – 8). The major objectives of this thesis are, to improve the ecological and economical sustainability of prawn farming by the applicationof BFT and to improve the nutrient utilisation in aquaculture systems.
Description:
School of Industrial Fisheries, Cochin University of Science and Technology
Sini, T K; Dr. Mathew, P T(Central Institute of Fisheries Technology, December , 2007)
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Abstract:
The present study aimed at the utlisation of microbial organisms for the
production of good quality chitin and chitosan. The three strains used for the
study were Lactobacillus plantarum, Lactobacililus brevis and Bacillus subtilis.
These strains were selected on the basis of their acid producing ability to reduce
the pH of the fermenting substrates to prevent spoilage and thus caused
demineralisation of the shell. Besides, the proteolytic enzymes in these strains
acted on proteinaceous covering of shrimp and thus caused deprotenisation of
shrimp shell waste. Thus the two processes involved in chitin production can be
affected to certain extent using bacterial fermentation of shrimp shell.Optimization parameters like fermentation period, quantity of inoculum,
type of sugar, concentration of sugar etc. for fermentation with three different
strains were studied. For these, parameters like pH, Total titrable acidity (TTA),
changes in sugar concentration, changes in microbial count, sensory changes
etc. were studied.Fermentation study with Lactobacillus plantarum was continued with 20%
w/v jaggery broth for 15 days. The inoculum prepared yislded a cell
concentration of approximately 108 CFU/ml. In the present study, lactic acid and
dilute hydrochloric acid were used for initial pH adjustment because; without
adjusting the initial pH, it took more than 5 hours for the lactic acid bacteria to
convert glucose to lactic acid and during this delay spoilage occurred due to
putrefying enzymes active at neutral or higher pH. During the fermentation study,
pH first decreased in correspondence with increase in TTA values. This showed
a clear indication of acid production by the strain. This trend continued till their
proteolytic activity showed an increasing trend. When the available sugar source
started depleting, proteolytic activity also decreased and pH increased. This was
clearly reflected in the sensory evaluation results. Lactic acid treated samples
showed greater extent of demineralization and deprotenisation at the end of
fermentation study than hydrochloric acid treated samples. It can be due to the
effect of strong hydrochloric acid on the initial microbial count, which directly
affects the fermentation process. At the end of fermentation, about 76.5% of ash was removed in lactic acid treated samples and 71.8% in hydrochloric acid
treated samples; 72.8% of proteins in lactic acid treated samples and 70.6% in
hydrochloric acid treated samples.The residual protein and ash in the fermented residue were reduced to
permissible limit by treatment with 0.8N HCI and 1M NaOH. Characteristics of
chitin like chitin content, ash content, protein content, % of N- acetylation etc.
were studied. Quality characteristics like viscosity, degree of deacetylation and
molecular weight of chitosan prepared were also compared. The chitosan
samples prepared from lactic acid treated showed high viscosity than HCI treated
samples. But degree of deacetylation is more in HCI treated samples than lactic
acid treated ones. Characteristics of protein liquor obtained like its biogenic
composition, amino acid composition, total volatile base nitrogen, alpha amino
nitrogen etc. also were studied to find out its suitability as animal feed
supplement.Optimization of fermentation parameters for Lactobacillus brevis
fermentation study was also conducted and parameters were standardized. Then
detailed fermentation study was done in 20%wlv jaggery broth for 17 days. Also
the effect of two different acid treatments (mild HCI and lactic acid) used for initial
pH adjustment on chitin production were also studied. In this study also trend of
changes in pH. changes in sugar concentration ,microbial count changes were
similar to Lactobacillus plantarum studies. At the end of fermentation, residual
protein in the samples were only 32.48% in HCI treated samples and 31.85% in
lactic acid treated samples. The residual ash content was about 33.68% in HCI
treated ones and 32.52% in lactic acid treated ones. The fermented residue was
converted to chitin with good characteristics by treatment with 1.2MNaOH and
1NHCI.Characteristics of chitin samples prepared were studied and extent of Nacetylation
was about 84% in HCI treated chitin and 85%in lactic acid treated
ones assessed from FTIR spectrum. Chitosan was prepared from these samples
by usual chemical method and its extent of solubility, degree of deacetylation,
viscosity and molecular weight etc were studied. The values of viscosity and
molecular weight of the samples prepared were comparatively less than the
chitosan prepared by Lactobacillus plantarum fermentation. Characteristics of protein liquor obtained were analyzed to determine its quality and is suitability as
animal feed supplement.Another strain used for the study was Bacillus subtilis and fermentation
was carried out in 20%w/v jaggery broth for 15 days. It was found that Bacillus
subtilis was more efficient than other Lactobacillus species for deprotenisation
and demineralization. This was mainly due to the difference in the proteolytic
nature of the strains. About 84% of protein and 72% of ash were removed at the
end of fermentation. Considering the statistical significance (P<O.05) in the
extent of demineralization and deproteinisation, we have taken 0.8N HCI for the
demineralization study and 0.6M NaOH for deprotenisation study. Properties of
chitin and chitosan prepared were analyzed and studied.
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 .