The following points highlight the seven main products to improve marine biotechnology. The products are: 1. Therapeutic Natural Products 2. Bio-Molecular Materials 3. Marine Bio-Pesticide 4. Bio-Monitors 5. Biomass Production 6. Bioremediation 7. Bioprocess Engineering.
Product # 1. Therapeutic Natural Products:
We already have an idea about the various Therapeutic natural products found in terrestrial plants and microorganisms were the basis of early drug to be explored and used as sources of new drugs, albeit with declining rates of success.
By contrast, recent trends suggest that exploration and use of marine resources, especially microorganisms (bacteria, fungi, and micro algae), for drug development has barely begun. Many bioactive substances from the marine environment already have been isolated and characterised, with great promise for the treatment of human diseases.
The compound manoalide from a Pacific sponge, for example, has spawned more than 300 chemical analogs, with a significant number of these going on to clinical trials as anti-inflammatory agents.
To date, exploitation of natural agents from the sea has been hindered by problems with limited or sporadic distribution and production. Much more research must be conducted to determine what seasonal factors and life cycle or reproduction states are linked with natural production of an agent.
Factors influencing production may include diet, physical and chemical conditions, distribution by phylogenetic affiliation, geographic location, water depth, or associations with symbiotic microorganisms. Knowledge of these factors will be important in developing methods for producing selected metabolites, either from whole organisms or in vitro from cell or tissue cultures of plants and animals.
Many of these compounds are very large and complex molecules, requiring very elaborate biochemical processes; as a result, it can be difficult to synthesise them or clone all the genes for standard production through fermentation.
Product # 2. Bio-Molecular Materials:
Enzymes produced by marine bacteria are important in biotechnology due to their range of unusual properties. As far as the enzymes are concerned some are saltresistant, a characteristic that is often advantageous in industrial processes. The extra cellular proteases are of particular importance and can be used in detergents and industrial .cleaning applications, such as in cleaning reverse-osmosis membranes. Vibrio species have been found to produce a variety of extracellular proteases.
Vibrio alginolyticus produces six proteases, including an unusual detergent-resistant, alkaline serine exoprotease. This marine bacterium also produces collagenase, an enzyme with a variety of industrial and commercial applications, including the dispersion of cells in tissue culture studies.
Other research has demonstrated the presence in algae of unique haloperoxidases (enzymes catalysing the incorporation of halogen into metabolites). These enzymes could become valuable products, because halogenation is an important process in the chemical industry.
Japanese researchers have developed methods to induce a marine alga to produce large amounts of the enzyme superoxide dismutase, which is used in enormous quantities for a range of medical, cosmetic, and food applications.
An unusual group of marine microorganisms from which enzymes have been isolated are the hyperthermophilic archaea (previously called archaebacteria), which can grow at temperatures over 100°C and therefore require enzyme systems that are stable at high temperatures.
Archaea typically are found in extreme environments, such as hot springs, animal guts, hydrothermal vents, sewage sludge digesters, and hypersaline habitats, including the Great Salt Lake. Thermostable enzymes offer distinct advantages, many still to be discovered, in research and industrial processes. Thermostable DNA-modifying enzymes, such as polymerases, ligases, and restriction endonucleases, already have important research and industrial applications.
Hot springs in Yellowstone National Park provided the first archaeon (Thermus aquaticus) from which thermostable DNA polymerases were isolated. These novel enzymes (the Taq® polymerases) became the basis for the polymerase chain reaction (PCR), a useful technique for studying genetic material.
In 1989, thermostable DNA polymerase was designated Molecule of the Year by Science magazine. Comparable enzymes continue to be discovered. Most enzymes involved in the primary metabolic pathways of thermophilic bacteria and archaea are dramatically more thermostable than are their counterparts living at moderate temperatures.
Expanded study of enzymes from thermophilic marine microorganisms will contribute to the understanding of mechanisms of enzyme thermostability and should enable the identification of enzymes suitable for industrial applications as well as modification of enzymes to enhance thermostability.
Product # 3. Marine Bio-Pesticide:
Natural marine products have the potential to replace chemical pesticides and other agents used to maximise crop yields and growth. Continued Federal support for R&D in this area is likely to result in useful natural pesticides that would provide greater specificity and fewer harmful side effects than do conventional synthetic agents.
An example of a marine biopesticide in use today is Padan, which was developed from a bait worm’s toxin known to ancient Japanese fishermen. This natural pesticide has demonstrated activity against larvae of the rice stem borer, the rice plant skipper, and the citrus leaf miner, among other pests.
More recently, scientists in Montana discovered novel compounds in marine algae and marine sponges containing symbiotic microorganisms. These compounds promoted growth and stimulated germination and increased root and coleoptile lengths in test plants.
Several sponge and nudibranch species produce terpenes, a broad class of aromatic compounds used in solvents and perfumes and known to deter feeding by fish. Extracts derived from this same sponge and nudibranch species also demonstrated powerful insecticidal activity against two species, grasshoppers and the tobacco hornworm.
Product # 4. Bio-Monitors:
Marine organisms can provide the basis for development of biosensors, bio-indicators, and diagnostic devices for medicine, aquaculture, and environmental monitoring. One type of biosensor employs the enzymes responsible for bioluminescence.
The lux genes, which encode these enzymes, have been cloned from marine bacteria such as Vibrio fischeri and transferred successfully to a variety of plants and other bacteria. The lux genes typically are inserted into a gene sequence, or operon, that is functional only when stimulated by a defined environmental feature.
The enzymes responsible for toluene degradation, for example, are synthesised only in the presence of toluene. When lux genes are inserted into a toluene operon, the engineered bacterium glows yellow-green in the presence of toluene.
This genetically engineered system “reports” that biodegradation of a specific chemical, in this case toluene, is proceeding. Another type of bio-monitor that holds great promise is the gene probe, which can be used to identify organisms that pose health hazards or may be useful in research.
Specific gene probes can be employed, for example, to detect human pathogens in seafood and recreational waters; fish pathogens in aquaculture systems; microorganisms capable of mediating desired chemical transformations (e.g., toxic chemical degradation, CO2 assimilation, metal reduction); and specific fish stocks in fish migration and recruitment studies.
Product # 5. Biomass Production:
Approximately 40 percent of all primary energy production, or photosynthesis, occurs in the seas. In this process, oceanic plants (phytoplankton, seaweeds, seagrasses) take up carbon dioxide (CO2) and, with light energy from the sun, convert it into organic carbon (primarily sugars) and oxygen.
The oceans contain 50 times as much carbon dioxide as does the atmosphere, and it is estimated that primary production incorporates 35 gigatons (1 gigaton = 1 × 1015 grams) of carbon into marine biomass annually.
This abundant source of fuel for energy production has not been tapped commercially because it is not competitive with soybean meal and other easily harvested, traditional sources of biomass, and also because, regardless of the source, biomass is not competitive with other types of fuels.
Research on the use of biotechnology to enhance biomass production and utility is another scope of marine biotechnology.
At least three general approaches are being explored:
i. The enzyme that captures CO2 for photosynthesis-ribulose bisphosphate carboxylase/oxygenase or “RUBISCO”-is relatively inefficient, so supercomputers are being used to verify structural information, and the enzyme is being redesigned to optimise its function.
ii. The chemical composition of biomass can be altered to make it more suitable for particular applications. For example, marine microalgae are being genetically engineered to boost their lipid content, with the aim of providing a source of alternative fuels that is more economical than are conventional sources.
iii. Biotechnology is being used to convert biomass to ethanol and other alternative forms of energy and chemical feed-stocks.
Product # 6. Bioremediation:
Bioremediation shows great promise for addressing problems in marine environments and in aquaculture. These problems include catastrophic spills of oil in harbors and shipping lanes and around oil platforms; movement of toxic chemicals from land, through estuaries, into the coastal oceans; disposal of sewage sludge, bilge waste, and chemical process wastes; reclamation of minerals, such as manganese; and management of aquaculture and seafood processing waste.
The full potential for marine organisms and processes to contribute new waste treatment and site remediation technologies cannot be realised without enhanced understanding of the unique conditions in marine environments.
For example, oxidation-reduction (redox) states can fluctuate in coastal and estuarine sediments. The impact of changing redox conditions on biodegradation of environmental contaminants must be understood before waste management and remediation strategies and predictive models can be developed for contaminated sediments.
Product # 7. Bioprocess Engineering:
The emerging discipline of bioprocess engineering involves the application of biological science in manufacturing, to produce products such as biopharmaceuticals and natural bioactive agents.
Bioprocess engineering requires an understanding of the biological system employed (such as a marine organism), isolation and purification of a product, and translation of the product into a stable, efficacious, and convenient form. An emerging area of interest is the potential of marine bacteria and fungi to produce unusual chemical structures with no parallels in terrestrial organisms.
Small-scale studies have begun to indicate the richness of marine microorganisms as sources for novel lead structures. The study of such materials is impeded, however, by the corrosive nature of seawater nonconventional fermentors. The use of marine organisms as a basis for bioprocess engineering depends on the development of salt-resistant reactors.
In addition, numerous technical advances are required for progress in bioprocess engineering in general. For example, improved methods are needed for the isolation and purification of products from the producing organisms. Advances in this area most likely will come from emerging partnerships between the Federal Government and the private sector.