new 3- marine organisms as sources of useful...
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3- Marine Organisms as Sources of Useful Materials
Since ancient times, man has harvested marine organisms both as food and as a source of
useful materials. In the past two or three decades, however, three major areas can be
clearly identified:
(1) The exploitation and management of the natural resources,
(2) The transition from harvesting the marine environment to farming those useful
species through aquaculture technology; and
(3) The increased interest in screening marine organisms as potential sources of
bioactive compounds of potential medical and agricultural interest.
Bioactive compounds are natural compounds produced by certain organisms and affect
the growth, metabolism, reproduction, and survival of other types of organisms. Those
include potentially effective therapeutic agents with antiviral, antibacterial, and antitumor
properties produced mainly by invertebrates from the classes Porifera (e.g. sponges),
Cnidaria, Mollusca, Echinodermata, Bryozoa, and Urochordata.
Sessile Marine Organisms as Potential Sources of Natural Products
The immobile existence of sessile (non-mobile or permanently attached) organisms such
as reef-building corals, sponges, sea fans, bryozoans, tunicates and macroalgae, gives rise
to its own problems. Chief among these is the need to keep from being eaten, the need to
keep from being fouled or overgrown, the need to successfully reproduce, and the need to
ward off microbial infections. These organisms often rely on secondary metabolites, or
biochemical 'natural products' to overcome many of the difficulties of life.
1. Natural Products Keep Marine Organisms from Being Eaten
Natural products can be toxic or noxious (bad tasting/smelling) to would-be consumers of
sessile organisms. Various marine macroalgae, sponges, and other organisms avoid being
eaten because they produce and sequester these products.
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2. Natural Products Allow Marine Organisms to Maintain Space
Sessile organisms are potentially susceptible to overgrowth, or crowding out by
competitors. For example, the photosynthetic organisms like macroalgae (seaweed),
crowding by other organisms is detrimental because it can shade the algae. To reduce
competition, some seaweed, sponges, and other sessile organisms use a chemical
defensive strategy called allelopathy. Allelopathy is the suppression of growth of one
species by another due to the release of toxic substances.
3. Natural Products Help Ensure Survival Success
The vast majority of sessile invertebrates produce free-living, planktonic larvae. A
planktonic larval stage is certainly an effective means of broadcast-dispersal of larvae,
but at the time of settlement, the larvae must be able to successfully locate habitats
meeting their specific juvenile and adult survival needs.
Since the ability to correctly recognize and settle into suitable habitat is literally a matter
of life and death, it is not surprising that many marine invertebrate larvae possess a
remarkable ability to 'smell their way' onto appropriate settlement sites. This revolves
around the ability of larvae to sense and home in on waterborne chemical cues originating
from adult conspecifics, favored adult prey items, or reliable co-occurring organisms.
Almost as important, chemical cues can also elicit an avoidance behavior in larvae, e.g.,
if the cues in question indicate the presence of large numbers of potential predators.
4. Natural Products Protect Marine Organisms Against Infections
Large number of marine natural products demonstrate pronounced antibiotic, antiviral, or
antifungal properties suggests that these compounds may well play a similar role in
nature. In marine environment as many as 1 million bacterial cells in a single milliliter of
seawater, what would be truly surprising is if sessile organisms in the marine
environment didn't have a way to naturally defend themselves against potential infection
and disease.
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Examples of Useful Materials from Marine Organisms
Medical Applications of Aquatic Biotechnology
Many scientists believe that oceans and freshwater habitats possess near limitless
opportunities for the identification of medical products. In the future, it is anticipated that
new and important classes of drugs will be derived from aquatic organisms and used for
human benefit, and marine organisms may be used as biomedical models to understand,
diagnose, and treat human diseases.
Chitin White, horny substance found in the exoskeleton of the phylum Arthropoda— which
includes crabs, lobsters, and shrimp. It is a polysaccharide consisting of units of N-acetyl
glucosamine.
Because of its unique properties, together with its by-products, chitosan, chitotriose, and
chitobiose, it has found applications in industries, medicine, and agriculture. These
complex carbohydrates are structurally similar to cellulose, which forms the tough outer
layer of the cell wall in plants. Cellulose is widely known as a source of dietary fiber.
Similarly, chitin and chitosan are also sources of fiber. Eating vegetables and fruits to get
fiber is much gentler on your digestive tract than eating crab shells. Nonetheless, ground-
up extracts of crab shell can be purchased as a powder in many nutrition stores. Today,
more than a million people worldwide take chitin and chitosan in dietary supplements.
Their antibacterial, anti-fungal and anti-viral properties make them particularly useful for
applications. Research has shown that chitin and chitosan are non-toxic and non-
allergenic, so the body is not likely to reject these compounds as foreign invaders. Many
skin creams and contact lenses also contain chitin, and chitin has been used to create
nonallergenic dissolvable stitches that appear to stimulate healing when used in humans.
Production
• Start material head and shell of shrimp
• Chemical/Biochemical Process
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Chitosan
Chitosan is a natural product which is derived from the Polysaccharide chitin. It is a
Polysaccharide consisting units of the amino sugar D-Glucosamine.
The Chitosan has the unique ability to attach itself to lipids or fats. Chitosan fiber differs
from other fibers in that it possesses a positive ionic charge. This positive charge gives
Chitosan the ability to bind with negatively charged lipids, fats and bile acids.
There are no calories in Chitosan since it is not digestible. Chitosan attaches to fat in the
stomach before it is metabolized. The Chitosan traps the fat and prevents its absorption in
the digestive tract. The fat binds to the Chitosan fiber and becomes a large mass which
the body cannot absorb. This large mass is then eliminated from the body.
This dietary fiber is a valuable addition to a properly balanced weight management
program. Fibers also provide important cleansing attributes which aid in the digestive
process and promote digestive tract health. Chitosan can also help to lower cholesterol.
Glucosamine
This product is natural amine sugar extracted from the Chitin. As food additive and raw
material for pharmacy, it provides the building blocks for the body to make and repair
cartilage.
Monitoring Health and Human Disease
Limulus amoebocyte lysate (LAL) test The limulus amoebocyte lysate (LAL) test is an extract of blood cells (amebocytes) from
the horseshoe crab Limulus polyphemus that is used to detect bacterial endotoxins.
Endotoxins, also called lipopolysaccharides, are part of the outer cell wall of many
bacteria such as E. coli and Salmonella. Researchers discovered that horseshoe crab
blood would clot when exposed to whole E. coli or purified endotoxins. They later
determined that amebocytes— which are similar to human white blood cells—in
horseshoe crab blood could be lysed, centrifuged, and freeze-dried to create a lysate that
can be used in an LAL test.
Endotoxins are a type of cytotoxins, molecules that are toxic to cells. Endotoxins can
cause instant death to many cells grown in culture. In humans, exposure to endotoxins
from certain bacteria can result in mild symptoms such joint pain, inflammation, and
fever to more severe conditions such as a stroke. Certain endotoxins can be lethal.
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The LAL test, a rapid and very effective assay
for endotoxins in human blood and fluid samples,
to ensure that cytotoxins are not present in biotechnology drugs such as
recombinant therapeutic proteins.
It is also used to detect bacteria in raw milk and beef.
In addition, many medical companies and hospitals use the LAL test to make sure
that surgical instruments, needles used for drawing blood and cerebrospinal fluid,
and implanted devices are endotoxin free.
The LAL test is the most sensitive and specific procedure available for the detection of
bacterial endotoxin because it can detect as little as 1 pg.
Calcitonin Salmon for Osteoporosis treatment
Osteoporosis, a condition characterized by a progressive loss of bone mass, creates
porous and brittle bones that can lead to fractures of the hip, legs, and joints, which
severely hinder an individual‟s lifestyle. Over 90% of the roughly 25 million Americans
affected by osteoporosis are women. A common treatment for osteoporosis is estrogen
therapy. This medication is ineffective for many women, and the long-term health effects
of estrogen are a concern. Other individuals are treated with human recombinant
calcitonin, a thyroid hormone that stimulates calcium uptake and bone calcification and
inhibits bone-digesting cells called osteoclasts. Recently, researchers have discovered
that some species of salmon produce a form of calcitonin with a bioactivity that is 20
times higher than that of human calcitonin. Cloned forms of salmon calcitonin are now
available for delivery as an injection form and a nasal spray.
Coralline hydroxyapatite bone graft substitute
The skeletons of reef forming corals partially consist of hydroxyapatite (HA) (a calcium
phosphate mineral), an important component of the matrix that constitutes bone and
cartilage in animals including humans. The biotechnology company Interpore
International has developed technology that allows HA implants to be cut into small
boxes and used to fill gaps in fractured bones. These boxes are ultimately invaded by
local connective tissue cells that speed repair. As a result, patients avoid needing bone
grafts from other parts of their body. These implants may also serve to fill bone material
lost around the root of a tooth.
Adhesives substances A number of adhesives have been identified in glue-like substance produced by mussels
and other shellfish. The mussels (Mytilus edulis) are
hinged shelled mollusks that live in harsh, physically
demanding environments. They typically adhere to rocks
or pilings at the edges of oceans. Day after day, these
creatures are pounded by waves. They dry out during low
tides, then get submerged and pounded by waves again as
the tide rises. How do they maintain their contacts to
rocks and other structures without being crushed or pulled
off the rocks? The answer lies in a unique form of
protein-rich superadhesive called byssal fibers (Figure ).
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Byssal fibers are several times tougher and more extensible than human tendons, which
themselves are tougher than steel. Adhesive and elastic properties of byssal fibers absorb
energy and stretch as waves tug away at the mussels. Although it would be cost
prohibitive to isolate byssal fibers from mussels directly (nearly 10,000 mussels would be
required for 1 gram of adhesive), scientists are using recombinant DNA techniques to
express the byssal fiber genes in bacteria and yeast to produce these adhesive proteins on
a large scale.
Although still several years from development, byssal fiber proteins are being considered
for a wide variety of diverse applications from automobile tires to shoes and from bone
and teeth repair strategies to soft body armor for soldiers. Other potential uses include
surgical sutures and artificial tendon and ligament grafts.
Manoalide Researchers have identified a Pacific sponge that produces a nonsteroidal compound
called manoalide. This substance possesses anti-inflammatory and analgesic properties
and is currently being investigated in clinical trials in humans.
Anticancer compounds Over a dozen different anticancer compounds have been isolated from marine
invertebrates, particularly sea sponges, tunicates, and mollusks. Many of these
compounds are in various stages of clinical trials that will ideally lead to new and
effective drugs on the market.
Conotoxins Several groups of researchers are studying venomous marine creatures with the hope of
identifying substances that may be used to
treat nervous system disorders.
Marine cone snails, a potentially lethal
species, produce conotoxins, molecules that
can target specific neurotransmitter
receptors in the nervous system. In 2004, the
FDA (Food and Drug Administration)
approved the drug Prialt, a peptide
conotoxin purified from the marine cone
snail Conus magus. Conotoxins such as
Prialt represent a promising new source of
neurotoxins with the ability to act as strong
painkillers by blocking neural pathways
that relay pain messages to the brain. Prialt
has been successfully used to treat chronic,
severe forms of pain such as back pain.
Anti-inflammatory compounds Researchers are also examining anti-inflammatory compounds found in coral extracts.
Such compounds may lead to new treatment strategies for skin irritations and
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inflammatory diseases such as asthma and arthritis. Table 4 lists examples of medical
compounds isolated from aquatic organisms.
Table 4 Examples of Medical Compounds from Aquatic Organisms
Researchers are developing culturing systems to provide adequate supplies of marine
organisms such as single-celled plankton called dinoflagellates, which contain
antitumor and cancer-treating abilities.
A Bryozoan's Medical Endosymbiont
Recently, a marine invertebrate belong to Bryozoa and called Bagula neritina was
shown to contain minute amounts of a compound that is active against certain types of
leukemia and Alzheimer. In fact it's not the bryozoan that makes the chemical. The
chemical, found in the bryozoan's tissues, is produced by its bacterial endosymbiont,
Candidatus Endobugula sertula. In exchange for a protective home in the bryozoan's
tissues, the bacteria produces a chemical called a bryostatin that makes the bryozoan
larvae taste bad to predators.
Nerve cell toxin from the pufferfish (Fugu rubripes)
The Japanese pufferfish, or blowfish (Fugu rubripes), has been getting a lot of attention
lately. Fugu is famous for its ability to swallow water and „puff up” when threatened and
to produce a potent nerve cell toxin called tetrodotoxin (TTX). TTX is one of the most
toxic poisons ever discovered (nearly 10,000 times more lethal than cyanide). In Japan,
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Fugu is a prized and very expensive delicacy for many sushi lovers who enjoy the food
quality of this tasty fish despite the risk (eating Fugu kills pearly 100 people, mostly in
Japan, each year). Scientists have used TTX to develop a greater understanding of how
proteins called sodium channels help neurons produce electrical impulses. TTX is a
deadly poison because it blocks sodium channels and prevents nerve impulse
transmission. An understanding of how TTX affects sodium channels has led to the
development of new drugs that are being tested not only as anesthetics to treat patients
with different types of chronic pain but also as anticancer agents in humans.
Figure 14 Pufferfish are Helping Scientists Discover New Wags to Treat Cancer and Chronic Pain.
Researchers are also working on sequencing the pufferfish genome, which contains
nearly the same number of genes as humans but in a much smaller genome. Fugu also
contains far less noncoding DNA (introns) than humans, so it is considered an ideal
model organism for studying the importance of introns.
Squalamine form dogfish A steroid called squalamine, first identified in dogfish sharks (Squalus acanthias),
appears to be a potent antifungal agent that may be used to treat life-threatening fungal
infections that can fatally affect patients with conditions such as AIDS and cancer.
Sharks rarely develop cancer, and shark cartilage has been proposed to be a rich source of
anticancer agents. Although no compounds from shark cartilage have demonstrated
effectiveness in controlled clinical trials, shark cartilage extracts possess antiangiogenic
compounds. Angiogenesis is the formation of blood vessels, a process that is often
required for growth and development of many types of tumors. By blocking blood vessel
formation, antiangiogenic compounds derived from marine species show promise for
inhibiting the growth of certain tumors.
Natural sunscreens Because many aquatic organisms live in harsh environments, scientists are optimistic that
they can learn from the adaptations these organisms have developed. For example,
researchers are currently studying marine organisms that show tolerance to ultraviolet
light as a potential source of natural sunscreens.
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Drugs from the sea
To date, few drugs from the sea have widespread use in the medical market; however, in
the future, recombinant DNA technologies will lead to enhanced abilities to produce bulk
quantities of bioactive compounds typically found in very low concentrations in aquatic
organisms. The next table presents the marine-derived potential therapeutic compounds.
Many of these are still undergoing preclinical evaluation, but several others are currently
being administered to patients as part of clinical trials. Information provided for each
product entry includes compound source, bioactivity, and clinical status.
Some promising potential therapeutic compounds derived from marine sources
Source Compound [clinical status] Activity
Microbe-Derived
Compounds
Cryptophycins [Clinical trials of
semi-synthetic cryptophycin 52
discontinued in 2002]
Antifungal , Cytotoxins ,
Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Curacin A [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Thiocoraline [Preclinical] DNA Polymerase
Inhibition
Sponge-Derived
Compounds
Bengamides and Derivatives
[Synthetic analog LAF389
withdrawn from Phase I clinical
trials in 2002]
Antitumor/Tumor
Growth Inhibition
Contignasterol (IZP-94005,
IPL576,092) [In clinical trials
(various phases]
Anti-Asthma Agent
Debromohymenialdisine (DBH)
[Phase I clinical trials]
Anti-Alzheimer Agent,
Osteoarthritis Treatment
Discodermolide [Phase I clinical
trials]
tubule interactive agent
Girolline (Girodazole) [Clinical trials
discontinued]
Protein Synthesis
Inhibition
Halichondrins [Synthetic analogs are
currently in clinical trials]
Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Hemiasterlins (H-286) [Preclinical] Cytotoxins ,
Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
KRN7000 [Phase I clinical trials
(Europe and Asia)]
Antitumor/Tumor
Growth Inhibition,
Immunostimulatory
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Lasonolides []Preclinical Antifungal,
Antitumor/Tumor
Growth Inhibition
Manoalide [Withdrawn from Phase
II clinical trials]
Analgesia, Anti-
Inflamatory
Topsentins [Preclinical] Anti-Inflamatory
Dictyostatin [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Latrunculins [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Laulimalide (and Synthetic Analogs)
[Preclinical]
Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Manzamine A [Preclinical] Anti-Infective Agent ,
Antitumor/Tumor
Growth Inhibition
Peloruside A [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Salicylihalamides [Preclinical] Vo-ATPase Inhibition
Cnidarian-Derived
Compounds
Pseudopterosins [: in use as a
commercial skin cream additive; in
preclinical development for medical
applications]
Analgesia, Anti-
Inflamatory
Eleutherobin [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Sarcodictyins [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Helminth-Derived
Compounds
Anabaseine (Hoplonemertine toxin)
[Phase I clinical trials]
Anti-Alzheimer Agent
Molluscan-Derived
Dolastatins [Phase II, Phase I
clinical trials]
Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Kahalaide F Cytotoxins , Gene
Inhibition
Spisulosine [Currently in Phase I
clinical trials]
Antitumor/Tumor
Growth Inhibition
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Ziconotide (Prialt®) [FDA-
Approved]
Analgesia
Bryozoan-Derived
Compounds
Bryostatin 1 [In Phase II clinical
trials]
Immunosuppressive,
Protein Kinase C
Binding Inhibition
Ascidian-Derived
Compounds
Aplidine (Aplidin®) [Phase II
clinical trials]
Apoptosis Induction
Didemnin B [Withdrawn from
clinical trials]
Protein Synthesis
Inhibition
Ecteinascidin 743 (Yondelis®) Apoptosis Induction
Diazonamide A [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Vitilevuamide [Preclinical] Tubulin/Actin
Interactive Agents
(primarily anti-cancer)
Vertebrate-Derived
Compounds
Squalamine [Phase I/Phase II clinical
trials; also sold as a non FDA-
approved dietary supplement]
Anti-Angionegic Agent,
Antitumor/Tumor
Growth Inhibition
Neovastat® (AE-941) [Preclinical] Anti-Angionegic Agent ,
Antitumor/Tumor
Growth Inhibition
Clinical Trials
Clinical trials of new drug candidates for safety and efficacy evaluation are mandatory before a
drug candidate is cleared for marketing. The new candidate drugs are approved for clinical
practice, after they have been evaluated in different phases of clinical trials phase I to phase II to
phase III
In phase I clinical trials, the tolerability of the test compound in different doses in healthy
volunteers is first assayed.
In Phase II clinical trials, the therapeutic effects of the test drug are carefully monitored in
patients.
In phase III clinical trials, data on several thousands patients in various well-defined indications
are collected.
Marine microorganisms Many of the compounds isolated from marine organisms, such as sponges, may be
produced by associated bacteria. For example:
- Several diketopiperazines previously ascribed to the sponge Tedania ignis, are
produced by a marine Micrococcus sp. associated with this sponge.
- The halichondrins, complex polyether macrolides are originated in microbial flora
components from the marine sponge Halichondria okadai. Halichondrin B, an
extremely potent antimitotic agent, inhibits tubulin polymerization and microtubule
assembly.
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Non-medical Products Enzymes from the sea
Taq polymerase, isolated from hot-springs Archae Thermus aquaticus, which allowed
for the development of the PCR as a powerful tool in molecular biology.
Heat-stable ligases and restriction enzymes The ocean also has proved to be an
excellent source of enzymes and other products that have played an important role in
basic and applied research. For example, bacteria living near hydrothermal vents have
yielded a second generation of heat-stable enzymes for use in PCR and DNA-modifying
enzymes, including ligases and restriction enzymes.
Salt resistant enzymes Other enzymes produced by marine bacteria possess a variety of
interesting properties that may result in important applications in the future. For example,
some enzymes are salt resistant, which renders them ideal for industrial scale-up
procedures involving high-salt solutions.
Bioluminescent Marine Bacteria
Useful products from Bioluminescent Marine Bacteria In addition of detecting environmental pollution by the bioluminescent bacterium Vibrio
harveyi, researchers have discovered marine species of Vibrio that produce a number of
proteases, including several unique proteases that are resistant to detergents used in
many manufacturing processes. As a result, these detergent-resistant proteases may have
potential applications for degrading proteins in cleaning processes, including their use in
laundry detergent for removing protein stains in clothes.
Vibrio is also a good source of collagenase, a protease used in tissue culturing to digest
the connective tissues holding cells together so the individual cells can be dispersed into
cell culture dishes.
Bioluminescent Marine Bacteria, a source of Lux Genes
According to recent estimates, close to three fourths of all marine organisms can release
light through a process known as bioluminescence. For marine fish, bioluminescence can
be used to attract mates in dark ocean environments. Bioluminescence in many marine
species is created by bacteria such as Vibrio fischeri that use the marine organism as a
host (Figure 15).
Fig. Bacterial luminescence. Colonies of P. mandapamensis from the light organ of the cardina fish
Siphamia tubifer are shown growing on a nutrient seawater agar plate. The plate was photographed in
room light (left) and (the same plate) in the dark by the light produced by the bacteria (right).
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Bacteria such as Vibrio have been used as biosensors to detect cancer- causing chemicals
called carcinogens, environmental pollutants, and chemical and bacterial contaminants in
foods. Vibrio fischeri and another marine bioluminescent strain called Vibrio harveyi
create light through the action of genes called lux genes. Several lux genes encode
protein subunits that form an enzyme called luciferase (derived from the Latin lux ferre,
meaning “light bearer”).
Figure 15 Bioluminescent Marine Bacteria, a source of Lux Genes Bioluminescent marine bacteria, such
as Vibrio fischeri shown (above) glowing in the light-releasing organs of a deep-sea fish and (below) Lux
genes encode the enzyme luciferase that uses oxygen and stored energy (ATP) to convert luciferin into
oxyluciferin. This reaction releases light. Lux genes have served important roles as reporter genes to allow
biologists to study gene expression. By cloning genes into plasmids containing lux genes, expression is
indicated by glowing cells.
The lux genes have been cloned and used to study gene expression in a number of
unique ways
The lux genes can also serve as valuable reporter genes. If inserted into animal or
plant cells, the luciferase encoded by the lux plasmid cause these cells to fluoresce
(Figure 15). In this manner, the lux plasmid is acting as a “reporter” to provide a
visual indicator of gene expression.
Lux genes have recently been used to develop a fluorescent bioassay to test for
tuberculosis (TB). TB is caused by the bacterium Mycobacterium tuberculosis,
which grows slowly and can exist in a human for several years before the individual
may develop TB. For the TB bioassay, scientists introduced lux genes into a virus
that infects M. tuberculosis. Saliva from a patient who may be infected with M.
tuberculosis is mixed together with the lux-containing virus. If M. tuberculosis is in
the saliva sample, the virus infects these bacterial cells, which can be detected by
their glowing.
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Biomass and Bioprocessing
One newly emerging area of marine biotechnology involves the exploration of marine
biomass. A mat of aquatic weeds of algae represents biomass, as does a school of fish.
Marine plants (including seaweeds, grasses, and planktons) use photosynthesis to capture
and convert a tremendous amount of energy (nearly 30% of all energy production
worldwide) from the sun into chemical energy. Can chemical energy from such biomass
be harvested? Scientists are examining ways in which algae and plants may he used to
produce alternative fuels. For example, it may be possible to take advantage of the rapid
biosynthetic capabilities of marine algae with their ability to mass-produce hydrocarbons
and lipids in extraordinary quantities to provide alternate sources of materials that are
normally cost prohibitive to produce or isolate from natural materials. Similarly, it may
be possible to convert marine biomass into fuels such as ethanol.
The U.S. Naval Research Lab has investigated potential ways to use plankton as
underwater “fuel cells”. Plankton at the water‟s surface release energy as they undergo
photosynthesis, whereas plankton closer to the sediment at the bottom of the ocean
(where there is less oxygen) use other reactions to generate energy. As a result, scientists
have found that these plankton create a natural voltage gradient from the surface to the
ocean floor that can be harvested to produce an indefinite source of electricity. In the
future, the ocean may turn out to be a valuable resource for providing energy.
Lastly, scientists are exploring ways in which biomass of marine algae may be used to
increase absorption of carbon dioxide and decrease greenhouse effects on the earth.
Related to applications of biomass, marine scientists are exploring ways in which
bioprocessing may involve marine products. Bioprocessing is a general term that
describes engineering approaches to produce a biological product such as a recombinant
protein (Proteins that can result from the expression of recombinant DNA within living
cells). Algae may potentially be very valuable for expressing recombinant proteins.
Researchers have found that they can make an abundance of proteins, such as antibodies,
in marine algae because they can be grown on a very large scale.
Marine biologists are exploring how marine organisms may be used to synthesize a
variety of polymers and other biomaterials, which may be used for industrial
manufacturing processes. For instance, oyster shell proteins are being considered as
additives in detergents and other solvents as nontoxic, biodegradable alternatives to
currently used materials.