Biology Reference
In-Depth Information
reduce with increasing depth. Thus, compared with about 3 x 10
5
microbial
cells/ml of surface waters, at 2000 m deep, the cell counts may be as low
as 3000 microbial cells/ml.
These diverse environmental conditions have a
profound infl uence on biodiversity of organisms in the ocean, each organism
having a metabolism adapted to such conditions, leading to
typical size and
proximate compositions, particularly lipid (Haard, 1998). Many marine
organisms form symbiotic associations among themselves with a view to
survive the harsh conditions of the ocean. Most marine organisms also
produce a number of bioactive secondary metabolites, which, although,
are not directly involved in central physiological functions, yet contribute
to their fi tness and survival under the extreme habitats. These secondary
metabolites (also called natural products) are organic compounds that are
not directly involved in the normal growth, development or reproduction
of organisms.
There is a vast diversity in such secondary metabolites,
which consist of alkaloids, terpenoids, sulfated polysaccharides, peptides,
nitrogen heterocyclics, nitrogen-sulfur heterocyclics, sterols, and other
novel compounds. Absence of these secondary metabolites, although
may not result in immediate death of these organisms, but causes long
term impairment of their survivability and fecundity. The functions of
these compounds are usually of an ecological nature as they are used
as defenses against predators, parasites and diseases for inter-species
competition and to facilitate reproductive processes (attracting mates
by color, smell etc.). These compounds are produced by marine species
such as algae, corals, and microorganisms. Extracts of these organisms,
which contain these compounds have been found to have excellent
therapeutic effects (Bhakuni and Rawat, 2005; Kim et al., 2008). Table 7.1
gives the biological activities of diverse marine organisms, which can be
Table 7.1
Different bioactive
compounds from marine sources
as cure for various diseases
Analgesic agents
Anti-Alzheimer agents
Anti-asthma agents
Anti-bacterial agents
Anti-cancer agents
Anti-fungal agents
Anti-infl ammatory compounds
Anti-malarials
Anti-tumor agents
Anti-viral agents
Apoptosis induction compounds
Immuno-stimulatory agents
Immuno-suppressive agents
Osteoarthritis suppressors
