Because secondary metabolites exist in very small quantities as marine natural
products within organisms, large samples in the dozens of kilograms are required,
taking into account the recovery rate in the isolation process, the quantities used in
activity measurement, and losses. Preliminary experimentation should be conducted
to estimate the necessary sample amount and ensure an adequate size.
Close attention must be paid during the specimen sampling process to ensure as
little mixture with other specimens as possible, and organisms must be identified
through accurate classification. Because of degradation and other changes that may
occur with chemical components during sampling or transportation, the specimens
used in experimentation should be immediately chilled or frozen with dry or regular
ice and taken to the laboratory quickly for frozen storage. Plant samples should be
dried as quickly as possible for long-term preservation.
The precise sampling site and time must be recorded for samples, and appearance (color and gloss, smell, texture, and shape) should be photographed or
otherwise recorded. Information should be kept in a logbook, and samples of the
specimen should be separated, stored, and accurately identified.
A. Seaweeds
Seaweeds are best collected between March and June, when they are at their
highest florescence. They should be collected in their entirety, including roots
(adhesive organs). Shapes and colors may vary greatly even within the same
type, and as many examples as possible should be collected when organisms
are thought to belong to the same species.
B. Fish and Invertebrates
Depending on the type of fish, methods such as dragging, trawling, seining,
jigging, and stow netting may be used; for cephalopods such as squids and
octopuses, a gill net, a long line, or jigging may be used. For crustaceans, fish
pots may be used with crabs and beam trawling for shrimp. Shellfish are
collected by dredge or sampler.
C. Plankton
Plankton specimens may be collected by using plankton nets of different mesh
sizes and filtering seawater on board the vessel or at the scene. Zooplankton
typically requires 100 mesh or greater, while 20 mesh suffices for phytoplankton. When collecting large volumes, specimens may be gathered
according to size through stepwise connection and seawater filtering from large
to small mesh sizes.
D. Microorganisms
When collecting substances within seawater or the ocean floor, various types of
water sampler or bottom sampler may be used to collect samples in sterilized
canisters for transport to the laboratory. These may then be diluted and isolated
on a plate containing sterilized seawater or enriched for around three days for
plate medium isolation. Once separated, specimens may be obtained by
mass-culturing the microorganisms in media that suit their growth conditions.
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353
products within organisms, large samples in the dozens of kilograms are required,
taking into account the recovery rate in the isolation process, the quantities used in
activity measurement, and losses. Preliminary experimentation should be conducted
to estimate the necessary sample amount and ensure an adequate size.
Close attention must be paid during the specimen sampling process to ensure as
little mixture with other specimens as possible, and organisms must be identified
through accurate classification. Because of degradation and other changes that may
occur with chemical components during sampling or transportation, the specimens
used in experimentation should be immediately chilled or frozen with dry or regular
ice and taken to the laboratory quickly for frozen storage. Plant samples should be
dried as quickly as possible for long-term preservation.
The precise sampling site and time must be recorded for samples, and appearance (color and gloss, smell, texture, and shape) should be photographed or
otherwise recorded. Information should be kept in a logbook, and samples of the
specimen should be separated, stored, and accurately identified.
A. Seaweeds
Seaweeds are best collected between March and June, when they are at their
highest florescence. They should be collected in their entirety, including roots
(adhesive organs). Shapes and colors may vary greatly even within the same
type, and as many examples as possible should be collected when organisms
are thought to belong to the same species.
B. Fish and Invertebrates
Depending on the type of fish, methods such as dragging, trawling, seining,
jigging, and stow netting may be used; for cephalopods such as squids and
octopuses, a gill net, a long line, or jigging may be used. For crustaceans, fish
pots may be used with crabs and beam trawling for shrimp. Shellfish are
collected by dredge or sampler.
C. Plankton
Plankton specimens may be collected by using plankton nets of different mesh
sizes and filtering seawater on board the vessel or at the scene. Zooplankton
typically requires 100 mesh or greater, while 20 mesh suffices for phytoplankton. When collecting large volumes, specimens may be gathered
according to size through stepwise connection and seawater filtering from large
to small mesh sizes.
D. Microorganisms
When collecting substances within seawater or the ocean floor, various types of
water sampler or bottom sampler may be used to collect samples in sterilized
canisters for transport to the laboratory. These may then be diluted and isolated
on a plate containing sterilized seawater or enriched for around three days for
plate medium isolation. Once separated, specimens may be obtained by
mass-culturing the microorganisms in media that suit their growth conditions.
10.2 Researching Natural Marine Substances
353