Deepthi, Augustine; Dr.Rosamma, Philip(Cochin University of Science And Technology, May , 2014)
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Abstract:
The thesis is comprised of seven chapters. Chapter 1 gives a general introduction to marine actinomycetes; Chapter 2 gives an account on the morphological, biochemical and physiological characterization of marine actinomycetes. Comprehensive description of molecular identification and phylogenetic analysis of actinomycetes is dealt with in Chapter 3. The antimicrobial property with special reference to antivibrio activity is described in Chapter 4. Chapter 5 explores the melanin production ability of marine actinomycetes, characterization of melanin and evaluation of its bioactivity. Chapter 6 illustrates the study on chitinolytic Streptomyces as antifungal and insecticidal agents. Summary and Conclusion of the study is presented in Chapter 7, followed by References and Appendices.The present study provides an insight into the various actinomycetes occurring in the sediments of Arabian Sea and Bay of Bengal. Streptomyces was found to be the dominant group followed by Nocardiopsis. Eventhough generic level identification is possible by traditional phenotypic methods, species level identification necessitate a polyphasic approach including both phenotypic and genotypic characterization. Antibiotic production coupled with biogranulation property helped in the effective utilization of the actinomycetes for the control of vibrios. Melanin from Streptomyces bikiniensis was proved to be a promising antioxidant and photoprotectant. Marine actinomycetes were found to be a good source of hydrolytic enzymes and the chitinolytic isolates could be explored as biocontrol agents in terms of antifungal and insecticidal property. The present study explored the potential of marine actinomycetes especially Streptomycetes as a promising source of bioactive molecules for application in aquaculture and pharmaceutical industry.
Hareeshkumar, P V; Dr.Basil, Mathew(Cochin University of Science And Technology, January , 1992)
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Abstract:
The Arabian Sea is an area of complex air-sea interaction
processes with seasonal reversing monsoons. The associated
thermohaline variability in the upper layers appears to
control the large scale monsoon flow which is not yet
completely understood.
The variability in the thermohaline fields is known to
occur in temporal domain ranging from intra-diurnal to
inter-annual time scales and on spatial domains of few tens of
kilometers to few thousands of kilometers. In the Arabian Sea
though the surface temperature was routinely measured by both
conventional measurements and satellites, the corresponding
information on the subsurface thermohaline field is very
sparse due to the lack cw adequate measurements. In such
cases the numerical models offer promise in providing
information on the subsurface features given an initial
thermohaline field and surface heat flux boundary conditions.
This thesis is an outcome of investigations carried out
on the various aspects of the thermohaline variability on
different time scales. In addition to the description of the
mean annual cycle. the one dimensional numerical models of
Miller (1976) and Price et a1 (1986) are utilised to simulate
the observed mixed layer characteristics at selected locations
in the Arabian Sea on time scales ranging from intra-diurnal
to synoptic scales under variable atmospheric forcing.