As an emerging discipline, marine biotechnology has a lot to offer especially as early forms of life originated in the oceans before it docked ashore. Living organisms in the oceans have to encounter extremes of atmospheric conditions. Adapting to this challenging environment that covers a major portion of earth and also having to bear extremes of light, temperature and pressure--- are microorganisms of incredible biodiversity.

Just as the landmass in which we live is divided into continents and geographical zones, the oceans consists of 5 layers starting from the surface and extending to extreme depths. They are the Epipelagic Zone(up to 200 meters from surface), Mesopelagic Zone(between 200 meters to 1000 meters), Bathypelagic Zone(between 1000 meters to 4000 meters), Abyssopelagic Zone(between 4000 meters and 6000 meters), and the Hadalpelagic Zone(between 6000 meters and beyond 11,000 meters). Therefore, the scope of marine biotechnology is breathtaking, considering the fact that biotechnology has a role to play in each of these zones vis a vis screening the biota that exists there, in terms of its utility value to man.

The oceans have a repository of more than 1,50,000 species of algae and in excess of 200,000 invertebrates. That apart, you can find sponges, corals, worms, sea squirts, sea snails and slugs, star fish, sea cucumbers and a host of other creatures. Therefore, it is but natural, that these marine biota and several more, have potential for facilitating new drug discoveries, especially as marine algae and bacteria produce biochemicals that are very much different from their land based cousins. Marine biotechnology happens to be the instrument for exploiting the enormous bio-diversity in the oceans. Its application could be in pharmaceutics, food, paper, and beverage industry.

Research in marine biotechnology has resulted in several drug discoveries. Let's have a look at some of these discoveries in terms of their source.

Sponges

Sponges cannot move on their own as they are forever attached to a substrate.
But several medicines especially for cancer have been isolated from sponges.


Azidothymidine or AZT is obtained from the sponge Cryptotethya and was the first antiretroviral medicine approved for treating HIV/AIDS, and continues to be used even today, especially for prevention of mother to child transmission of disease.

Discodermolide undergoing trials as an anti-cancer drug has been isolated from the Caribbean sea sponge called discodermia dissoluta. Hemiasterlin isolated from the South African sea sponge Hemiasterella minor is also a promising cancer medication

Laulimalide a natural marine product isolated from the Okinowan Ocean sponge Cacospongia mycofijensis has pharmacological action similar to that of taxol and is several times more potent than taxol in multi drug resistant cell lines, and is used for treating breast and ovarian cancers that are taxol resistant.

The drugs Ara-A, and Ara-C have also been developed from sea sponges, the former for the treatment of herpes, and the latter for the treatment of myelocytic leukemia.

Corals

Human bone structure and that of the coral are same, in that, both are porous and interconnected. Human bone is composed of hydroxyapatite. Some companies use coral heads plus a patented chemical process in converting coral to hydroxyapatite, retaining the coral structure, but providing a medium for new bone tissues to grow.

The Fluorescence emanating from the Bahamian brain coral could be a source of new biotech lights in future. Kainic acid obtained from coral reefs in Japan is used as a diagnostic agent in Huntington's chorea, a fatal nervous disorder.

Algae

The brown algae are the source for the versatile drug Fucoidan that can be used to treat leukemia type 1 besides being an anticoagulant, as well as a cancer drug.

The red algae found off the Pacific coast of Philippines and Chile is the source for Carrageenans which is undergoing clinical tests for use as an antiretroviral and for treatment of genital herpes.

Scripps Institution of Oceanography has isolated Pestalone, a new chlorinated benzophenone antibiotic from the surface of brown algae Rosenvingea sp found in the Bahamas Islands and which exhibits moderate cytotoxicity in human tumor cells.

Marine Fungus

The research division of Yamanouchi Pharmaceutical Co., Ltd has found a new antifungal antibiotic YM-202204 (1) from the marine fungus Phoma sp. Q60596 effective against Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus.

A research lab at the Hong Kong University of Science and Technology in association with other researchers elsewhere is testing an antibiotic and antifouling compound isolated from a marine fungus Cladosporium sp. F14 grown on tryptone/yeast extract media in the presence of glucose.

Cone Snails

Ziconotide is a powerful painkiller from cone snails of species Conus magus, especially used for treating severe chronic pain and generally found in the Indian Ocean.

Sea Hares

Dolastatins isolated from Sea hares that are found in the Indian Ocean is an important cancer medication under development.

Sea Squirt and Spiny dogfish

Ecteinascidin 743 and Aplidinen isolated from the Carribean Sea Squirt Ecteinascidia turbinate from the Carribean Sea are undergoing trials for use as an anti cancer medication. The Carribean Sea Squirt Ecteinascidia turbinata is the source for the promising anti cancer agent Trabectedin.

Squalamine isolated from the Spiny dogfish Squalus acanthias found especially in the Atlantic and Pacific Oceans is an antibiotic substance under development.

Conclusion

Marine food sources are continuously being undermined by spurt in demand as well as excessive fishing. The use of trawlers during monsoon season has had its negative impact on the fragile marine eco-system as also bottom trawling in the high seas. That apart, using marine organisms as a source for making medicines entails certain difficulties as for example, they cannot be easily cultured, difficulties in making them synthetically, and large scale collection of source organisms is not possible, and this is the reason that hampers clinical development of drug from marine sources. Nevertheless, a large part of marine organisms still remain to be screened for potentially useful material, and hence untapped potential of deep sea marine organisms is phenomenal

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