Biotechnological Advancement, Applications in
Fisheries and Aquaculture
Fisheries and Aquaculture
Introduction
What Aquaculture offers?
Aquaculture offers the huge potential of
providing nutritional as well as economic security to the ever-growing
population around the globe. The beauty of aquaculture is its flexibility which
allows it to be used in all the kind of water resources varying from freshwater
to highly saline water. Aquaculture itself is an amalgamation of a multitude of
disciplines including biology, chemistry, environment, engineering etc.
providing nutritional as well as economic security to the ever-growing
population around the globe. The beauty of aquaculture is its flexibility which
allows it to be used in all the kind of water resources varying from freshwater
to highly saline water. Aquaculture itself is an amalgamation of a multitude of
disciplines including biology, chemistry, environment, engineering etc.
Aquaculture and biotechnologists
Biotechnological interventions have
realized it as a multi-million dollar industry. Today aquaculture is considered
as an organized lucrative business sector and contributing enormously towards
the GDP of several countries.
realized it as a multi-million dollar industry. Today aquaculture is considered
as an organized lucrative business sector and contributing enormously towards
the GDP of several countries.
Some of the key biotechnological
interventions such as the development of inducing hormone, disease diagnosis
kit, probiotics, biofilter, selective breeding etc. have contributed enormously
in accelerating the pace of the blue revolution. The following section will
brief about the different biotechnological interventions in aquaculture along
with future prospects.
interventions such as the development of inducing hormone, disease diagnosis
kit, probiotics, biofilter, selective breeding etc. have contributed enormously
in accelerating the pace of the blue revolution. The following section will
brief about the different biotechnological interventions in aquaculture along
with future prospects.
What is Biotechnology?
Biotechnology is defined by several
authors using various way but the simplest one is presented by the United
Nations Convention on Biological Diversity as “any technological application
that uses biological systems, living organisms or byproducts thereof, to make
or amend products or procedures for particular use (Kafarski, P., 2012).
authors using various way but the simplest one is presented by the United
Nations Convention on Biological Diversity as “any technological application
that uses biological systems, living organisms or byproducts thereof, to make
or amend products or procedures for particular use (Kafarski, P., 2012).
Wikipedia states biotechnology as functional
biology that comprises the use of living organisms and bioprocess in
engineering, technology, medicine and other fields requiring bio-products
(source -Wikipedia). Biotechnology is used widely for human welfare such as
food production, environment management, health management, etc. The integration
of biotechnology with aquaculture is not a new aspect and being practiced for
decades.
biology that comprises the use of living organisms and bioprocess in
engineering, technology, medicine and other fields requiring bio-products
(source -Wikipedia). Biotechnology is used widely for human welfare such as
food production, environment management, health management, etc. The integration
of biotechnology with aquaculture is not a new aspect and being practiced for
decades.
The versatility of Biotechnology offers
many potential applications for the development of fisheries and aquaculture.
The success of next-generation aquaculture will be largely guided by the
technology influenced through biotechnological intervention. All the four
important pillars of aquaculture such as seed, feed, disease and environment
can be very well integrated with biotechnological findings which can ultimately
improve the output several folds.
many potential applications for the development of fisheries and aquaculture.
The success of next-generation aquaculture will be largely guided by the
technology influenced through biotechnological intervention. All the four
important pillars of aquaculture such as seed, feed, disease and environment
can be very well integrated with biotechnological findings which can ultimately
improve the output several folds.
Interventions of Biotechnology
in Aquaculture
The success of aquaculture is governed
by mainly four components – quality seed, quality feed, disease management and
soil water quality management. Even though the major investment in aquaculture
is towards feeding management but the success of aquaculture is equally
dependent on the other three components too.
by mainly four components – quality seed, quality feed, disease management and
soil water quality management. Even though the major investment in aquaculture
is towards feeding management but the success of aquaculture is equally
dependent on the other three components too.
Biotechnological
interventions are very well prevalent in all these components and explained in
detail in the following sections.
interventions are very well prevalent in all these components and explained in
detail in the following sections.
Role of Biotechnology
in Seed Production
in Seed Production
Quality and pure seed is the most important
criterion to start aquaculture. Availability of quality seed with improved
performance in large number is the key factor in the development of semi
intensive and intensive aquaculture industry.
criterion to start aquaculture. Availability of quality seed with improved
performance in large number is the key factor in the development of semi
intensive and intensive aquaculture industry.
Development of induced breeding techniques and
selective breeding are the revolutionary development in hatchery technology of
aquaculture which has lightened the lamp of the blue revolution.
selective breeding are the revolutionary development in hatchery technology of
aquaculture which has lightened the lamp of the blue revolution.
Induced Breeding and
Biotechnology
Biotechnology
Induced breeding based on hypophysation
(Chaudhuri, H., & Alikunhi, K. H., 1957) was developed long back during the
1950s but it is the production of synthetic hormones which has helped in
disseminating the technology of induced breeding to the ground level. Synthetic
super-active analogues were developed using biotechnological tools such as
recombinant DNA technology and protein engineering with better inducing
efficacy at a lower dose. Such analogue
possesses modified amino acid in position 6, which leads to higher resistance
to peptidase. It has also altered the polarity and tertiary structure of the
GnRHa, which outcomes in an enhanced receptor binding affinity (Zohar and
Mylonas, 2001; Thomas, P. C., 2003).
(Chaudhuri, H., & Alikunhi, K. H., 1957) was developed long back during the
1950s but it is the production of synthetic hormones which has helped in
disseminating the technology of induced breeding to the ground level. Synthetic
super-active analogues were developed using biotechnological tools such as
recombinant DNA technology and protein engineering with better inducing
efficacy at a lower dose. Such analogue
possesses modified amino acid in position 6, which leads to higher resistance
to peptidase. It has also altered the polarity and tertiary structure of the
GnRHa, which outcomes in an enhanced receptor binding affinity (Zohar and
Mylonas, 2001; Thomas, P. C., 2003).
Figure 2 : Different forms
of GnRH amino acid sequences
of GnRH amino acid sequences
The race is still on in finding species
specific more efficient analogue using a bioinformatics approach to reveal the
effect of amino acid substitution on receptor binding study. Currently,
different types of inducing agents such as ovatide, ovaprime, ovapel etc. are
commercially used widely in the hatchery (Chattopadhyay, N. R., 2016).
specific more efficient analogue using a bioinformatics approach to reveal the
effect of amino acid substitution on receptor binding study. Currently,
different types of inducing agents such as ovatide, ovaprime, ovapel etc. are
commercially used widely in the hatchery (Chattopadhyay, N. R., 2016).
New candidate hormones such as
Kisspeptin are also identified from different fishes as a key regulator of
breeding representing upstream in the biological pathway of breeding and synthetic
Kisspeptin hormone has shown to be effective in improving the reproductive
performance of fishes (Rather et al., 2016).
Kisspeptin are also identified from different fishes as a key regulator of
breeding representing upstream in the biological pathway of breeding and synthetic
Kisspeptin hormone has shown to be effective in improving the reproductive
performance of fishes (Rather et al., 2016).
Improved Seed
Production (Selective Breeding)
Production (Selective Breeding)
Production of improved quality seed in
terms of growth performance, disease resistance, and environmental adaptability
is present and future of hatchery technology. Selective breeding is acting as a
vital tool in the hatchery. Many successful examples of such species are GIFT,
Jayanti rohu, common carp, salmon, sea bass etc. (Gjedrem et al., 2012)
are available around the globe. Selective breeding is at present only viable
methodology to produce specific pathogen resistant seed. Efforts are going on
around the globe to produce SPR shrimp and fish for disease free aquaculture.
terms of growth performance, disease resistance, and environmental adaptability
is present and future of hatchery technology. Selective breeding is acting as a
vital tool in the hatchery. Many successful examples of such species are GIFT,
Jayanti rohu, common carp, salmon, sea bass etc. (Gjedrem et al., 2012)
are available around the globe. Selective breeding is at present only viable
methodology to produce specific pathogen resistant seed. Efforts are going on
around the globe to produce SPR shrimp and fish for disease free aquaculture.
The genetic improvement of a fish stock
involves selection, cross/outbreeding, and hybridization. Selectively bred
stocks with superior traits such as disease resistance and rapid growth have
been produced and used in aquaculture. Selective breeding could be done by two
approaches one is traditional selective breeding (select high performing
individuals) and another is MAS (Marker Assisted Selection) breeding. The
former one could be used only for the traits which are visible like growth but
for others traits like disease resistance and carcass, MAS is the best option.
Molecular markers are direct reflection of the genetic diversity at the DNA
level. A number of approaches have been established to obtain molecular
markers, including VNTR, RAPD, SNP, AFLP, SSR, RFLP and others. These markers
can be employed to tag quantitative trait loci (QTLs) and assist the breeding
program. Association of markers with any trait (QTL) can lead to the
identification of genes responsible for resistance or susceptibility. Selection
based on marker data is called Marker Assisted Selection (MAS) and, if a gene
is used, the process is called Gene Assisted Selection (GAS).
involves selection, cross/outbreeding, and hybridization. Selectively bred
stocks with superior traits such as disease resistance and rapid growth have
been produced and used in aquaculture. Selective breeding could be done by two
approaches one is traditional selective breeding (select high performing
individuals) and another is MAS (Marker Assisted Selection) breeding. The
former one could be used only for the traits which are visible like growth but
for others traits like disease resistance and carcass, MAS is the best option.
Molecular markers are direct reflection of the genetic diversity at the DNA
level. A number of approaches have been established to obtain molecular
markers, including VNTR, RAPD, SNP, AFLP, SSR, RFLP and others. These markers
can be employed to tag quantitative trait loci (QTLs) and assist the breeding
program. Association of markers with any trait (QTL) can lead to the
identification of genes responsible for resistance or susceptibility. Selection
based on marker data is called Marker Assisted Selection (MAS) and, if a gene
is used, the process is called Gene Assisted Selection (GAS).
Markers like SNP which are highly
abundant across the genome are very much helpful in selective breeding and with
the advent of new advanced technologies like NGS (Next Generation Sequencing),
identification of these markers is now very easy and economical (Agarwal et
al.,2016). CIFA has released 1st batch of jayanti rohu produced through
selective breeding in 1997(50 years of Indian independence so called it jayanti
rohu) with a better growth rate (17% more). Further disease resistant Jayanti
rohu (resistant to Aeromonas hydrophila) is also produced by CIFA
(Mahapatra et al., 2017).
abundant across the genome are very much helpful in selective breeding and with
the advent of new advanced technologies like NGS (Next Generation Sequencing),
identification of these markers is now very easy and economical (Agarwal et
al.,2016). CIFA has released 1st batch of jayanti rohu produced through
selective breeding in 1997(50 years of Indian independence so called it jayanti
rohu) with a better growth rate (17% more). Further disease resistant Jayanti
rohu (resistant to Aeromonas hydrophila) is also produced by CIFA
(Mahapatra et al., 2017).
Assisted Reproduction
Technique
Technique
Assisted reproductive techniques (ART)
have now been widely assimilated in the management of infertile couples.
Although this is now being used in the case of humans but it can be very well
used in the hatchery to produce quality spermatozoa. Milt collected through
stripping also contains a bunch of dead spermatozoa, resulted in the failure of
fertilization.
have now been widely assimilated in the management of infertile couples.
Although this is now being used in the case of humans but it can be very well
used in the hatchery to produce quality spermatozoa. Milt collected through
stripping also contains a bunch of dead spermatozoa, resulted in the failure of
fertilization.
Flow cytometry based techniques such as FACS (Fluorescent
Activated Cell Sorting) can be used to segregate the inactive dead spermatozoa
from the live and motile sperms using some specific dye. It provides a way for
sorting a varied mixture of cells into two or more containers, one cell at a
time, based upon the exact light scattering and fluorescent features of each
cell.
Activated Cell Sorting) can be used to segregate the inactive dead spermatozoa
from the live and motile sperms using some specific dye. It provides a way for
sorting a varied mixture of cells into two or more containers, one cell at a
time, based upon the exact light scattering and fluorescent features of each
cell.
The separated cells (live and motile sperms) could be collected in a specific
container and further used in breeding. However, this technique is still in the
infancy stage but holds huge potential especially for endangered species or
species with less fecundity (Agarwal et al., 2017).
container and further used in breeding. However, this technique is still in the
infancy stage but holds huge potential especially for endangered species or
species with less fecundity (Agarwal et al., 2017).
Surrogate Broodstock
Technology
Technology
This technology holds huge potential for
aquaculture as well as in the conservation of those species which are difficult
to breed in captivity. The concept of Tuna from Mackerel or Trout from Salmon (Takeuchi
et al., 2004; Yoshizaki, G., & Yazawa, R., 2019) has been emerged
during the recent time, spreading hope for hatchery seed production of several
important species for both conservation and aquaculture point of view.
aquaculture as well as in the conservation of those species which are difficult
to breed in captivity. The concept of Tuna from Mackerel or Trout from Salmon (Takeuchi
et al., 2004; Yoshizaki, G., & Yazawa, R., 2019) has been emerged
during the recent time, spreading hope for hatchery seed production of several
important species for both conservation and aquaculture point of view.
Scientists have come up with another that
offers great possible, a kind of surrogate breeding (a new aquaculture technology)
in which both sperm and egg of a species are produced within a related easily
cultivable species. In surrogate technology, another fish species are used to
produce spermatozoa and ova. To succeed a successful surrogate technology it is
compulsory to comprehend the mechanism involved in gonad development.
offers great possible, a kind of surrogate breeding (a new aquaculture technology)
in which both sperm and egg of a species are produced within a related easily
cultivable species. In surrogate technology, another fish species are used to
produce spermatozoa and ova. To succeed a successful surrogate technology it is
compulsory to comprehend the mechanism involved in gonad development.
Gonads progresses
from a particular type of cell know as Primordial Germ Cell (PGC), giving rise
to either spermatogonia or oogonia (future male testis or female ovaries). In
this method, the PGC of one fish (donor) is transplanted into the embryo of
another fish (receiver) and after maturation; the receiver fish produces the
gametes of the donor fish. This concept offers a ray of hope to obtain big fish
from small fish which are difficult to breed in captivity such as Tuna from Mackeral,
which saves the time, space and input cost because small fishes need less
space, less food and lower maturation time.
from a particular type of cell know as Primordial Germ Cell (PGC), giving rise
to either spermatogonia or oogonia (future male testis or female ovaries). In
this method, the PGC of one fish (donor) is transplanted into the embryo of
another fish (receiver) and after maturation; the receiver fish produces the
gametes of the donor fish. This concept offers a ray of hope to obtain big fish
from small fish which are difficult to breed in captivity such as Tuna from Mackeral,
which saves the time, space and input cost because small fishes need less
space, less food and lower maturation time.
Transgenic fish
DNA is considered as blue print of life.
The transgenic or genetically modified organism is produced by bringing out
some changes in the genome using the genetic engineering approach of gene
transfer. Glo fish (GMO of zebrafish) and Aquaadvantage salmon are the two GMO
which are commercially available for ornamental and consumption purpose
respectively. FDA defined “genetically engineered (GE) animals” as those
animals altered by rDNA techniques, including all offspring that cover the
modification.
The transgenic or genetically modified organism is produced by bringing out
some changes in the genome using the genetic engineering approach of gene
transfer. Glo fish (GMO of zebrafish) and Aquaadvantage salmon are the two GMO
which are commercially available for ornamental and consumption purpose
respectively. FDA defined “genetically engineered (GE) animals” as those
animals altered by rDNA techniques, including all offspring that cover the
modification.
Development of transgenic produced by
the transfer of foreign genes into the fertilized eggs has become a powerful
tool for the study of gene expression in living animals in the field of
developmental biology, animal husbandry and aquaculture. By using various
transgenic techniques, investigators are pursuing to progress the genetic
traits of the fish used in commercial aquaculture system.
the transfer of foreign genes into the fertilized eggs has become a powerful
tool for the study of gene expression in living animals in the field of
developmental biology, animal husbandry and aquaculture. By using various
transgenic techniques, investigators are pursuing to progress the genetic
traits of the fish used in commercial aquaculture system.
Researchers are
trying to develop fish which are larger and grow faster, more efficient in
converting feed into muscle, resistant to disease, tolerant of low oxygen
levels in the water, and tolerant to freezing temperatures (Agarwal et
al.,2017). For example, AquAdvantage salmon, the trade label for a genetically changed
Atlantic salmon developed by AquaBounty Technologies.
trying to develop fish which are larger and grow faster, more efficient in
converting feed into muscle, resistant to disease, tolerant of low oxygen
levels in the water, and tolerant to freezing temperatures (Agarwal et
al.,2017). For example, AquAdvantage salmon, the trade label for a genetically changed
Atlantic salmon developed by AquaBounty Technologies.
The AquAdvantage salmon has been altered
by the addition of a growth hormone regulating gene from a Pacific Chinook
salmon and an antifreeze promoter from an ocean pout to the Atlantic salmon
genome. Normal salmon does not grow during winters but these genes enable it to
grow year-round. The purpose of the alterations is to upsurge the speed at
which the fish grows, without affecting its final size or other qualities. The marketable size of this fish reaches in 16 to 18 months rather than 3 years. This
technology is succeeding quickly and it is now conceivable to move genes
between indistinctly related species. Glo fish is available with diverse
variants and widespread between the ornamental fish keeper.
by the addition of a growth hormone regulating gene from a Pacific Chinook
salmon and an antifreeze promoter from an ocean pout to the Atlantic salmon
genome. Normal salmon does not grow during winters but these genes enable it to
grow year-round. The purpose of the alterations is to upsurge the speed at
which the fish grows, without affecting its final size or other qualities. The marketable size of this fish reaches in 16 to 18 months rather than 3 years. This
technology is succeeding quickly and it is now conceivable to move genes
between indistinctly related species. Glo fish is available with diverse
variants and widespread between the ornamental fish keeper.
Hybrid Identification
Hybrid seeds are the major concern of
recent years faced by aquaculturist, as many hatcheries are nowadays producing
hybrids that they sell on the name of original species for example hybrids of
IMC, hybrid of magur and gariepinus etc. It is almost impossible to distinguish
the original one from hybrid seed at spawn and fry stages using external characters.
recent years faced by aquaculturist, as many hatcheries are nowadays producing
hybrids that they sell on the name of original species for example hybrids of
IMC, hybrid of magur and gariepinus etc. It is almost impossible to distinguish
the original one from hybrid seed at spawn and fry stages using external characters.
Technology for hybrid identification
would really be of great use for farmers for the screening of quality seeds.
This problem could be solved to a satisfactory level by using molecular
approaches. Some private labs and government institutes have made some simple
and reliable kits, commercially available and show good results in the
identification of the hybrid with the wild one. These kits are purely PCR-based
kits which can identify a hybrid in just two steps with genomic DNA as starting
material. There is a particular kit manmade by CIFA, intended for the
identification of Labeo rohita, Catla catla and their hybrid
within a few hours in the early life stages. Three sets of primers are used to
amplify three diverse microsatellite markers from the genomic DNA isolated from
pectoral fins by using PCR.
would really be of great use for farmers for the screening of quality seeds.
This problem could be solved to a satisfactory level by using molecular
approaches. Some private labs and government institutes have made some simple
and reliable kits, commercially available and show good results in the
identification of the hybrid with the wild one. These kits are purely PCR-based
kits which can identify a hybrid in just two steps with genomic DNA as starting
material. There is a particular kit manmade by CIFA, intended for the
identification of Labeo rohita, Catla catla and their hybrid
within a few hours in the early life stages. Three sets of primers are used to
amplify three diverse microsatellite markers from the genomic DNA isolated from
pectoral fins by using PCR.
The PCR products using all three primer
sets differentiate the ‘hybrid–Rohu’ from wild types. The hybrid–Rohu DNA
yields specific PCR products with all three primer pairs. Only two PCR products
are got either from wild-type Catla DNA (by primer sets 1 and 2) or from
wild-type Rohu DNA (by primer sets 1 and 3). Such PCR based hybrid
identification protocol can be established for others also.
sets differentiate the ‘hybrid–Rohu’ from wild types. The hybrid–Rohu DNA
yields specific PCR products with all three primer pairs. Only two PCR products
are got either from wild-type Catla DNA (by primer sets 1 and 2) or from
wild-type Rohu DNA (by primer sets 1 and 3). Such PCR based hybrid
identification protocol can be established for others also.
Biotechnological
interventions in Health management in aquaculture
interventions in Health management in aquaculture
The disease is always a nightmare and major
concern in aquaculture and an estimate says that it accounts for the total loss
of over 6 billion dollars per year (Leung, T. L., & Bates, A. E., 2013). Managing
disease is always a challenging task but biotechnological interventions at
different stages such as diagnosis, prophylaxis, therapy etc is a big help for
aquaculturists. Aquaculture industries are in urgent need of fast-growing
disease-resistant varieties, rapid and sensitive disease diagnostic kit, and
development of economic and effective vaccines, probiotics and cell lines.
concern in aquaculture and an estimate says that it accounts for the total loss
of over 6 billion dollars per year (Leung, T. L., & Bates, A. E., 2013). Managing
disease is always a challenging task but biotechnological interventions at
different stages such as diagnosis, prophylaxis, therapy etc is a big help for
aquaculturists. Aquaculture industries are in urgent need of fast-growing
disease-resistant varieties, rapid and sensitive disease diagnostic kit, and
development of economic and effective vaccines, probiotics and cell lines.
Disease diagnosis
Prevention is always better than cure
and the same holds correct for aquaculture too. Monitoring pathogen at a different
stage during aquaculture can help in protecting the strength of biosecurity. In
this context, the development of simple, sensitive, reliable and rapid
technique for the detection of the pathogens is an urgent requirement.
Molecular techniques are potentially faster and more sensitive than
traditionally used methods for the identification of the pathogen based on
biochemical characteristics, serology and histology. PCR technology has
revolutionized the science of diagnosis.
and the same holds correct for aquaculture too. Monitoring pathogen at a different
stage during aquaculture can help in protecting the strength of biosecurity. In
this context, the development of simple, sensitive, reliable and rapid
technique for the detection of the pathogens is an urgent requirement.
Molecular techniques are potentially faster and more sensitive than
traditionally used methods for the identification of the pathogen based on
biochemical characteristics, serology and histology. PCR technology has
revolutionized the science of diagnosis.
Different variants of PCR are available
with the ability to detect even 1 copy number of the pathogen which is
otherwise undetected in other techniques. PCR-based diagnostic means have been established
for a number of pathogens disturbing aquaculture. During the last 15 years or
so, molecular techniques have been progressively engaged to diagnose fish
diseases. PCR based diagnosis protocols are available for almost all the OIE
listed pathogens. The testing of SPF seed is carried out using PCR techniques
only.
with the ability to detect even 1 copy number of the pathogen which is
otherwise undetected in other techniques. PCR-based diagnostic means have been established
for a number of pathogens disturbing aquaculture. During the last 15 years or
so, molecular techniques have been progressively engaged to diagnose fish
diseases. PCR based diagnosis protocols are available for almost all the OIE
listed pathogens. The testing of SPF seed is carried out using PCR techniques
only.
Nowadays different variants of PCR
such as LAMP, RPA etc. are available to facilitate field level sensitive and
rapid diagnosis of pathogen without the requirement of any expensive machine
based on isothermal amplification.
such as LAMP, RPA etc. are available to facilitate field level sensitive and
rapid diagnosis of pathogen without the requirement of any expensive machine
based on isothermal amplification.
Monoclonal antibodies (MAbs) produced by
hybridoma technology has contributed significantly to aquaculture. Monoclonal
antibodies are being employed in disease diagnosis, pathogen classification,
epidemiological analysis and development of vaccines.
hybridoma technology has contributed significantly to aquaculture. Monoclonal
antibodies are being employed in disease diagnosis, pathogen classification,
epidemiological analysis and development of vaccines.
Probiotics and
Bioaugmentation
Bioaugmentation
Applications of microbes as gut
probiotics and water probiotics are gaining popularity in aquaculture to
inhibit the proliferation of pathogens and maintaining healthy gut microbiota. The
health of pond bottom is critical in aquaculture and water probiotics are used
to reduce the organic load as well as the transformation of the toxic compounds
such as ammonia into nontoxic form. Such a bioagumentation process is popularly
practiced in shrimp farming nowadays.
probiotics and water probiotics are gaining popularity in aquaculture to
inhibit the proliferation of pathogens and maintaining healthy gut microbiota. The
health of pond bottom is critical in aquaculture and water probiotics are used
to reduce the organic load as well as the transformation of the toxic compounds
such as ammonia into nontoxic form. Such a bioagumentation process is popularly
practiced in shrimp farming nowadays.
Some of the other areas of health
management in aquaculture include the development of the vaccine. Several types
of research were carried out on the development of a vaccine based on Recombinant
DNA technology. At this time, only one DNA vaccine for infectious hematopoietic
necrosis virus (IHNV) is accessible within Canada only. RNAi based technology
has shown to provide protection against pathogen but still commercial level it
is not present. Even though such findings are not applied to a scale as
required but future aquaculture has to adopt this for overcoming the fear of
disease outbreak.
management in aquaculture include the development of the vaccine. Several types
of research were carried out on the development of a vaccine based on Recombinant
DNA technology. At this time, only one DNA vaccine for infectious hematopoietic
necrosis virus (IHNV) is accessible within Canada only. RNAi based technology
has shown to provide protection against pathogen but still commercial level it
is not present. Even though such findings are not applied to a scale as
required but future aquaculture has to adopt this for overcoming the fear of
disease outbreak.
Metagenomics
Microbial studies in aquaculture are
intended to understand the benefits as well as the harmful effect of microbes
on culture animals either it is fish or any other culture group such as
crustacean and molluscs. In this perspective, metagenomics can present a better
understanding of microbial association with the animal in different
circumstances such as healthy or diseased, stunted or fast-growing, etc. by
utilizing the genetic component of the sample from an organism or ecosystem. This
section is intended to showcase some important potential applications of
metagenomics in aquaculture.
intended to understand the benefits as well as the harmful effect of microbes
on culture animals either it is fish or any other culture group such as
crustacean and molluscs. In this perspective, metagenomics can present a better
understanding of microbial association with the animal in different
circumstances such as healthy or diseased, stunted or fast-growing, etc. by
utilizing the genetic component of the sample from an organism or ecosystem. This
section is intended to showcase some important potential applications of
metagenomics in aquaculture.
( A) Development of suitable probiotics
Identification of candidate probiotics
is possible by utilizing the comparative microbiome study of a healthy and
diseased animal. Metagenomics study reveals the in depth community composition
of healthy and diseased animals and helps to find out putative potential
probiotics bacteria from the healthy animal microbiome. Some of the study as
present in the earlier section has shown the dominance of certain bacterial
genera in the healthy animal sample and can be a candidate probiotics. A
similar approach can be used to identify water probiotics by comparing the
metagenome of different water bodies having good and bad quality water.
is possible by utilizing the comparative microbiome study of a healthy and
diseased animal. Metagenomics study reveals the in depth community composition
of healthy and diseased animals and helps to find out putative potential
probiotics bacteria from the healthy animal microbiome. Some of the study as
present in the earlier section has shown the dominance of certain bacterial
genera in the healthy animal sample and can be a candidate probiotics. A
similar approach can be used to identify water probiotics by comparing the
metagenome of different water bodies having good and bad quality water.
( B) In depth screening of antibiotic
resistance gene from the aquaculture system
resistance gene from the aquaculture system
Antibiotic resistance is a big threat
around the world and aquaculture is one of the foods producing sectors which is
considered as one of the reasons for such resistance development due to
indiscriminate use of antibiotics and also the aquatic system is considered as
environmental hotspot of horizontal gene transfer as it receives all the kind
of antimicrobials along with runoff water. The conventional method of AMR study
is possible only with cultivable bacteria and hence it can generate very
limited information on the prevalence of antibiotic resistance. Shotgun
metagenomics offers the opportunity for in-depth screening for the presence of
antibiotic resistance gene and hence it presents a better picture of AMR in
aquaculture.
around the world and aquaculture is one of the foods producing sectors which is
considered as one of the reasons for such resistance development due to
indiscriminate use of antibiotics and also the aquatic system is considered as
environmental hotspot of horizontal gene transfer as it receives all the kind
of antimicrobials along with runoff water. The conventional method of AMR study
is possible only with cultivable bacteria and hence it can generate very
limited information on the prevalence of antibiotic resistance. Shotgun
metagenomics offers the opportunity for in-depth screening for the presence of
antibiotic resistance gene and hence it presents a better picture of AMR in
aquaculture.
( C) Bioprospecting of novel protein
coding gene
coding gene
The marine ecosystem supports huge
microbial diversity of all the category starting from virus to bacteria and
fungi and many more. All these can be an excellent source of many important
lifesaving molecules such as enzymes, antibiotics, immunostimulants, etc. As
the majority of the microbial population is non-cultivable hence a conventional method of microbiological study cannot be used. Here shotgun
metagenomics can be used to generate in-depth genome information of the whole community which can be further used for bioprospecting of important gene coding
for the novel’s useful protein.
microbial diversity of all the category starting from virus to bacteria and
fungi and many more. All these can be an excellent source of many important
lifesaving molecules such as enzymes, antibiotics, immunostimulants, etc. As
the majority of the microbial population is non-cultivable hence a conventional method of microbiological study cannot be used. Here shotgun
metagenomics can be used to generate in-depth genome information of the whole community which can be further used for bioprospecting of important gene coding
for the novel’s useful protein.
( D) Amplicon metagenomics can be used
to characterize the microbial composition of pond soil and water.
to characterize the microbial composition of pond soil and water.
( E) It can be used as a part of the
disease surveillance program to target all the pathogens in one go.
disease surveillance program to target all the pathogens in one go.
( F) Microbial composition analysis of
biofloc and periphyton
biofloc and periphyton
Nutrigenomics
Feed involves a major cost in aquaculture and the price of feed is increasing a rate much more than the growth rate of aquaculture, mainly due to reduced availability of fishes for
fish meal preparation. In such a case fish meal can be substituted with other sources such as plant protein, poultry feather meal etc. The effect of these
substitutions on metabolism should be studied.
fish meal preparation. In such a case fish meal can be substituted with other sources such as plant protein, poultry feather meal etc. The effect of these
substitutions on metabolism should be studied.
Nutrigenomics provide best
approach to study these effects and hence will provide better understanding.
Understanding the biochemical and metabolic pathways complicated in the use of
dietary macro- or micronutrients and energy provided through feeds is beneficial
for assessing the reply of organisms to nutrients obtained from different
source, for optimizing dietary nutrient utilization and for diet development.
Biochemical pathway or metabolism of
nutrients are regulated through one or several enzymes, a product of gene so to
understand the effect of nutrients or interaction between nutrients and
gene it is necessary to study nutrition
with a molecular approach.
approach to study these effects and hence will provide better understanding.
Understanding the biochemical and metabolic pathways complicated in the use of
dietary macro- or micronutrients and energy provided through feeds is beneficial
for assessing the reply of organisms to nutrients obtained from different
source, for optimizing dietary nutrient utilization and for diet development.
Biochemical pathway or metabolism of
nutrients are regulated through one or several enzymes, a product of gene so to
understand the effect of nutrients or interaction between nutrients and
gene it is necessary to study nutrition
with a molecular approach.
Nutrigenomics
provides such an approach. The work of how genes and gene products interrelate
with dietary signals to affect phenotype and, equally, how genes and their
products metabolize nutrients is called nutritional genomics or
“nutrigenomics”. Development of
molecular techniques such as quantitative PCR, DD PCR, next-generation
sequencing etc. has served as a boost for nutrigenomics study. Nutrigenomics
can help in precise feed formulation for the betterment of aquaculture.
provides such an approach. The work of how genes and gene products interrelate
with dietary signals to affect phenotype and, equally, how genes and their
products metabolize nutrients is called nutritional genomics or
“nutrigenomics”. Development of
molecular techniques such as quantitative PCR, DD PCR, next-generation
sequencing etc. has served as a boost for nutrigenomics study. Nutrigenomics
can help in precise feed formulation for the betterment of aquaculture.
Conclusion and future
direction
direction
Aquaculture
is considered as a hope for growing population in terms of providing
nutritional and economic security but same cannot be achieved without
intensification. Biotechnology offers huge scope of integration with
aquaculture for better future and accelerating the pace of blue revolution. Biotechnology
can offer allot to aquaculture in bringing solution to several challenging
hurdle such as quality seed, disease, balanced feed etc. Further intensive
applied biotechnological research is the need of the current era for the betterment of
aquaculture.
is considered as a hope for growing population in terms of providing
nutritional and economic security but same cannot be achieved without
intensification. Biotechnology offers huge scope of integration with
aquaculture for better future and accelerating the pace of blue revolution. Biotechnology
can offer allot to aquaculture in bringing solution to several challenging
hurdle such as quality seed, disease, balanced feed etc. Further intensive
applied biotechnological research is the need of the current era for the betterment of
aquaculture.
Note:
Credit for writing above article goes to Dr. Sujit
Kumar, Assistant Professor
(Fish Biotechnology) Postgraduate Institute of Fisheries Education and Research,
Kamdhenu University, Gandhinagar-India.
Credit for writing above article goes to Dr. Sujit
Kumar, Assistant Professor
(Fish Biotechnology) Postgraduate Institute of Fisheries Education and Research,
Kamdhenu University, Gandhinagar-India.