Previous - Next
Biotechnology in animal health and production
In animal biotechnology, embryo transfer, use of monoclonal antibodies for diagnostics and production of efficient vaccines, hormonal manipulation for growth and productivity, and production of transgenics have been the main areas of work in the region. The situation in the different countries is described below.
Nucleus herd improvement using multiple ovulation and embryo transfer (MOET) in Open Nucleus Breeding Systems (ONBS)
Progress through the conventional approaches of genetic improvement of livestock in the region has been slow when compared with the genetic gains recorded in livestock of North America, Europe and Oceania. To overcome this limitation, MOET in ONBS is being advocated in developing countries as the technique may be especially valuable where the use of field progeny testing and artificial insemination (AI) has largely been a failure because of the need for an established infrastructure, both for field recording and AI.
As summarized by Hodges (1988), a genetically superior nucleus flock or herd established under controlled conditions where testing and genetic selection are carried out. The test group is first established by screening the base population for outstanding females. They are then recorded individually in the nucleus herd and the elite females among them are used by MOET with superior sires to contribute embryos which are carried by the recipient cows from the base population. The resulting offspring are reared and recorded and the males among them are evaluated genetically using the performance of their sibs and paternal half-sibs and their own performance where they exhibit the trait. From these an elite group of males with high breeding value is selected which is used in the base population for genetic improvement by natural service or AI. ONBS yields higher rates of genetic progress per annum than established progeny testing systems mainly because of the shorter generation interval. It is capable of being adapted to different species in which MOET is available. It also permits control of the mix of genes released to the base population. ONBS is flexible for the introduction of exotic germplasm from other populations, for example semen or embryos from temperate breeds and also for the continuous addition of outstanding individuals screened from the base population. China (Chengdu Fengherangshan Dairy Farm), India (Anand Dairy Cooperatives, Gujrat) and the Republic of Korea (Livestock Station, Suweon) are already practicing MOET in their nucleus herds. Similar work at private dairy farms in the Philippines, Thailand, Pakistan, Indonesia and Malaysia has been established, but it is still slow and needs strengthening (Mukherjee, 1989).
Embryo transfer research and application of the technique in improved production and genetic upgrading of cattle, buffaloes, swine, goats and sheep, in varying degrees, are being pursued in several of the Asian countries. Notable progress has been made in standardization of superovulation, synchronization and embryo collection techniques, evaluation and splitting of embryos, optimization of superovulation responses by laproscopy and ultrasonography, embryo manipulation, splitting and standardization of techniques for in vitro fertilization and sexing. Hundreds of calves using these techniques have been produced in China, India and the Republic of Korea and many have also been produced in Pakistan, the Philippines, Indonesia and Thailand, besides the thousands produced in the three developed countries of the region.
In Japan, ever since the standardization of the embryo transfer technique in 1979, the number of calves produced by embryo culture has steadily increased, from 73 in 1980 to 422 in 1984 and to 3 700 in 1988 (Yamauchi, 1989). Artificial production of identical twins (by slicing embryos in two halves) is also commonly practiced In 1988, 268 pairs of such twins were born throughout Japan. The conception rate has been improving, at around 60 percent for fresh embryos and about 40 percent for frozen embryos in the early 1990s. This technique is most commonly applied to the production of high quality beef cattle, such as Japanese Black.
The in vitro fertilization technique in cattle is also being used. In 1987, the first cattle triplet by in vitro fertilization in the world were born at the National Institute of Animal Industry, a research organization of the MAFF. The Institute has also succeeded in nuclear transplantation in cattle (Yamauchi, 1989).
Since the Asian countries have almost a monopoly on buffalo production, they need special research and development programmes on the species. Embryo transfer technology in buffaloes is much more difficult than in cattle. For instance, on average, five to six transferable embryos per donor are recovered in cattle against only 1.5 in buffaloes. Although some striking results have been obtained, such as the birth of a riverine calf from a swamp recipient in the Philippines, or the birth of the first IVF (in vitro fertilization) buffalo calf in India, the techniques need to be improved considerably to be efficient and commercially viable (Mukherjee, 1989).
The inception meeting of the regional FAO/UNDP project, RAS/89/001 "Biotechnology Development Network for Animal Production and Health", held in 1988, recommended that a cooperative project be taken up to study the normal hormonal profile of both riverine and swamp buffaloes. The hormonal profile has to be done under varying field conditions. At the same time, the structure of buffalo ovaries needs to be investigated in detail in various breeds. Since the number of primordial oocytes is very low in buffaloes, it is necessary to introduce an entirely different regime for superovulation.
The inception meeting further recommended that once the problem of superovulation in buffaloes had been sorted out, the situation in regard to other items of interest such as embryo splitting in vitro fertilization, etc. could be undertaken. The network should give high priority to the problems of buffalo embryo transfer and countries should work together to produce the necessary data within a defined timeframe on hormonal profiles, structure of the gonad and possible ovulatory regimes that can be taken up for priming the follicles to be followed up by a superovulatory regime.
Recombinant DNA technology and its applications
Recombinant DNA technology research in Asia is mainly confined to basic research by molecular biologists involving prokaryotes. This entails the discovery of suitable vectors (plasmids and nonplasmids) for the propagation of genes and the expression of these genes in selected hosts. Some biological laboratories are also engaged in DNA fingerprinting or restriction fragment length polymorphism work. Most of these biological laboratories are adequately equipped to undertake major research and train scientists from agricultural disciplines.
Only a few animal science/veterinary laboratories in the developing countries were engaged in molecular biology research. There are very few published reports on the work done, hence the information given below is based on information contained in various reports of the regional FAO/UNDP project on animal biotechnology mentioned earlier.
In China most of the work is being conducted by the National Laboratory of Agro-biotechnology, Beijing Agriculture University. The following are the highlights of the work in hand:
In India major work has been undertaken since the 1980s by the Indian Veterinary Research Institute (IVRI), Izatnagar and Bangalore campus and the National Institute of Immunology (NII), New Delhi, in the following areas.
In Japan, research in transgenic animals is highly advanced. In 1989, the National Institute of Animal Industry, following work in the United Kingdom, succeeded in in vitro culture of poultry eggs, achieving a good hatchability of about 34 percent. These results greatly increased the feasibility of transgenic chickens. As regards animal health, a recombinant vaccine of bovine Iymphatic leukaemia virus has been developed by the National Institute. A rabies virus vaccine was also developed. Highly specific and sensitive antibodies have been designed and are being used for the diagnosis of bovine Iymphatic leukaemia, rotavirus infection, mycobacteriosis and paratuberculosis, which are difficult to detect by traditional diagnostic methods (Yamauchi, 1989).
Japan is harvesting biotechnology for altering silkworms to increase the production and quality of silk filaments and to find new horizons of use other than traditional silk production. Using recombinant DNA technology, the National Institute of Sericultural and Insect Agricultural Technology is transferring the unique glossy yellow greenish silk colour from wild silkworms to domesticated silkworms. A technique of utilizing silkworms as the "factory" for producing useful substances has been established. In this method, for instance, the genes interferon are incorporated into nuclear polyhedrosis virus, and this virus is propagated in the body of silkworms so as to be mass produced. This technique was found to be more efficient than using bacteria as hosts and will be applied to the production of many other useful substances in the years ahead (Yamauchi, 1989).
The structure and function of hormones controlling the growth and metamorphoses of insects have been understood, and as a result it is now possible to control the growth of insects to some extent. Using this technique to control Silkworm larval cycle and maturity, it is now possible for Japanese scientists to control the thickness of silk filaments from one-tenth to three times that of ordinary ones (Yamauchi, 1989).
In Malaysia, genetic engineering research for animal production and health has been undertaken by the faculty of Biotechnology and Food Sciences and the Veterinary Faculty of University Pertanian Malaysia (UPM) and two Departments of University Malaysia (UM) -the Department of Genetics and Cellular Biology and the Institute for Advanced Studies. Research in progress or completed include:
In the Philippines, basic work on several aspects of animal health biotechnology is being conducted at the National Institute of Applied Microbiology and Biotechnology, Los Baņos. The Institute uses protoplast fusion and recombinant DNA technology in the genetic improvement of antibiotic producing microbial strains. Research on local production of tylosin and antibiotics for animal feed is also in progress. The National Biotechnology Institute, Los Baņos, has also undertaken work on the development of low cost biogas systems using crop residues, production of genetically improved lignolytic micro organisms, enzyme engineering techniques for synthesis of ligniases, and the low technology tumbler process of producing microbial proteins using selected strains of fungi and yeast which could be used as a feed ingredient for poultry and pigs.
As regards other Asian countries, the Veterinary Faculty of Kasetsart University, Thailand, the Central Research Institute for Animal Sciences, Bogor, Indonesia, and the Department of Animal Sciences, Agriculture University at Faisalabad, Pakistan, have initiated work on the identification of genetic markers for production and disease traits in livestock.
Biotechnology for the enhancement of feed production
Several Asian countries are involved in work on biodegradation of organic wastes for the production of animal feed or biogas. The majority of these studies cannot be categorically called biotechnological work since they involve known and old methods of degrading lignocellulosic materials for improvement of the nutritive value of feed. Therefore, as summarized by Mukherjee (1989), only those projects/laboratory research which involved either microbiological treatment for biodegradation or dealt with huge machineries/fermenters/powerplants are briefly mentioned.
In most of the provinces and autonomous regions of China, microbial treatment of lignocellulosic low-quality roughages is practiced to a varying extent. Yeast factories located at Shanghai, Jilin and Guang Dan, the Nanjing Fermentation factory and the Shunde Sugar factory produce single cell proteins containing 40-85 percent protein. Production of SCP using petroleum hydrocarbon, natural gases and methanol are also commonly practiced. Enzyme product factories in Wuxi and Tianjing produce various types of enzymes. The Shanghai Biochemistry Institute and the Beijing Institute of Biochemistry produce enzymes through genetic engineering work. Furthermore, at least 18 amino acids are produced using fermentation technology.
In India, the Indian Institute of Technology, New Delhi, undertook biochemical engineering research for the development of single cell proteins from waste biomass. The National Dairy Research Institute, Karnal, has been researching the enrichment of wheat straw using fungal (Coprinus) and urea treatment.
In Indonesia, the Central Research Institute for Animal Sciences, Bogor, has investigated prospects of protein enrichment of cassava tuber using yeast inoculum (Candida ingenuosa and Candida utalis), protein enrichment of rice straw and wood chips using Pleurotus Protein enrichment of rice straw using Coprinus was studied at the National Centre for Research in Biotechnology.
In Malaysia, utilization of agroindustrial wastes as animal feed using biotechnological methodologies is being emphasized. The role of rumen in the digestion of fibres in ruminants with a view to developing in vitro systems of digestion of fibrous materials has been studied. In this context, characterization of rumen bacteria with a view to manipulation of bacteria in future for effective digestion of fibre materials was undertaken. Production of protein biomass utilizing palm oilmill effluent as a substrate for thermophilic and mesophilic fungi has been explored.
In Pakistan, the National Agricultural Research Centre, Islamabad, has been studying the fungal treatment of agricultural wastes (cereal straws and sugar cane bagasse). The Department of Animal Nutrition, University of Faisalabad, has been researching mycelial biomass protein production from rice husk, rice polish and rice straw using Trichoderma harzanum.
Production of monoclonal antibodies and vaccines
Australia is promoting host specific vaccines. More specifically, viruses that are genetically engineered to infect selectively and prevent reproduction in feral animals are considered a desirable goal achievable in the short to medium term. Other goals include endocrine-directed vaccines to stimulate twinning in beef cattle, immunocastration, livestock growth rate increase, carcass composition such as reduced fat, and vaccines that compensate for stress-induced production losses of various kinds. Diagnostics are being used for quarantine management. Tailored vaccines exist for pig scours, chicken bursar disease and cattle tick. The latter is being promoted particularly in North Queensland where cattle tick causes babesiosis.
Most of the Asian laboratories dealing with the diagnosis of viral and bacterial diseases and production of vaccines have improved their diagnostic techniques during the past few years. The use of immunoflorescence microscope, radioimmunoassay and enzyme-linked immunosorbent (ELISA) techniques are quite common in most laboratories. Among the developing countries, work on the production of monoclonal antibodies has been quite intensive in the Republic of Korea, China, and India. Hybridoma techniques are also being used in some laboratories in Malaysia and the Philippines. Similar work is also in progress in Indonesia, Thailand and Pakistan.
In summary, as regards animal biotechnology in developing Asian countries, while high priority is being assigned to this subject, the need to maintain and further consolidate present work for animal improvement, health and production through conventional means is duly recognized.
Embryo Transfer (ET) has been most actively pursued in all countries. Large-scale public sector funds were available in China, India and Pakistan for the development of ET. China has developed considerable indigenous technology, e.g. production of hormones, embryo freezers and nitrogen tanks, which could be suitable for relatively poorer countries in Asia.
The Republic of Korea's efforts were very practical and included a cooperative approach of government, research institutions, universities and veterinary clinics. Initial private initiatives to develop ET in the Philippines, Thailand and Indonesia have been successful but not sustained.
Genetic engineering research in relation to domestic animals has had a good start in China, the Republic of Korea, India and Malaysia where substantial commitment has been made by the R&D funds of the respective governments. There are capable scientists in several Asian countries who could undertake molecular biology work, but because of limited research funds, such work has not yet gained momentum in many institutions.
Recognizing that the inadequate availability of animal feed is a major bottleneck in the development of livestock industry in the region, Asian countries are keen to promote the use of biotechnology in converting agricultural by-products and wastes into animal feed. Microbial digestion of raw materials using fungi and bacteria is being widely pursued. Characterization of rumen microbes in relation to their properties of digesting various fibrous feed materials will continue to be an important research subject in animal biotechnology in the region.
The discovery of monoclonal antibodies for the diagnosis of different diseases in the Republic of Korea, India and a few other Asian countries has stimulated industrial activities and the trend must spread to other countries in the region.
Biotechnology in fisheries and aquaculture
The fisheries and aquaculture industries in Asia contribute about 45 percent of world fish production (FAO/RAPA, 1993). These industries are significant contributors to the food supply, livelihood, foreign exchange earnings and socio-economic stability in rural areas of several Asian countries. At the global level fish production is stagnant, at around 100 million tonnes, or has even slightly declined in recent years. Overharvesting of the world's oceans is recognized as a global threat. To obviate this threat, the production of cultured fish must be accelerated. The ability to produce transgenic fish and shellfish in culture, which grow faster and larger with more efficient utilization of nutrients, is of particular value to developing countries, not only as a source of food, but also as export products.
Biotechnology offers great promises for fish disease control and feed production as well. Gynogenetic and polyploid progeny production and the use of growth hormones have significantly contributed to fish production (Guerrero, 1991). The application of hypophysation (injecting of pituitary gland extracts into mature fishes for the induction of spawning) has been widely practiced in Asia during the past two decades. The use of purified gonadotrophin hormone synthetic luteinizing hormone-releasing hormone (LH-RH) has further improved induced spawning techniques.
In China, following detailed discussions and workshops in the 1980s, a policy and plan for aquaculture biotechnology were included in the Seventh Five-Year Plan (1985-90). In 1987, they were also listed in the "863 Programmes", the state development programmes on high technologies, and received great attention from the Ministry of Aquaculture. Fish cell culture, sex control, chromosome manipulation, and to some extent transgenic production, have been the main areas of work.
China's success in fish cell culture, of grass carp, was reported in 1979 by the Freshwater Fishery Research Institute of Zhejiang Province. Up to now, more than ten fish cell strains have been cultured for producing vaccines. Bioreactors for industrial fish cell culture are being developed. Seaweed cell culture in China was first reported in 1985 and is being developed for further breeding work. Diploid gynogenesis, coupled with sex control is being used for mass production of all female common and crucian carps. Although triploid hybrids between 4n common carp (male) and 2n grass carp (female) have been obtained, the work is confined to laboratories.
China was one of the pioneers in transplanting of fish cell nucleus. In the mid-1970s, the reciprocal transplant of nucleus was accomplished between common carp and crucian carp. Of the cell hybrid fishes, 30 grew to sexual maturity and produced F2 and F3 progenies. In 1984, the F3 progenies were mass produced and these showed stable heredity and had 30 percent faster growth than their grandparents. A similar practice was carried out on grass carp and Megalobrama amblycephala; 26 of the hybrids grew well, matured sexually and were mass produced by aquaculturists. In 1988, live fries were produced from the fusion of blastulla cells and eggs in different fishes: Paramisgrunus dacryanus, Megalobrama amblycephala, grass carp, common carp and red crucian carp. This technique holds great promise for fish breeding.
In fishes, the two sexes differ in their productivity and body weight. For instance, in Tilapia males grow faster than the females, the converse of which is true for carps. Of the several methods of sex manipulation, through distant hybrids, hormone treatment, induced diploid gynogenesis, induced triploids, antoimmure castration, surgical castration, and gene technique, in China the first two are commonly used. Hybrid populations between Tilapia nilotica (female) and T. aurea (male) were 95 to 98 percent male, and on an average yielded about 25 percent higher than the higher yielding parent (T. nilotica). Moreover, the hybrid fish could tolerate lower water temperatures, and could be harvested more easily. Such all-male populations are already being mass cultured in China, the Philippines, Thailand and other countries. Israel has made comprehensive use of this technique.
As regards the use of hormones, using steroid hormones, induced females of T. mossambicais when crossed with male T. nilotica, produced super males with a "yy" sex chromosome combination. The "super males" crossed with female T. nilotica produced 100 percent male progenies which possessed the twin superiorities of being hybrid as well as male. The hybrids grew 38.5 percent faster than T. nilotica and the mass production increased by 43.4 percent. Although a sizeable gain, the difficulty in identifying the "super male" fish at fry stage is a major constraint to widespread exploitation.
As regards genetic engineering, Chinese scientists have succeeded in identifying and isolating the gene controlling growth hormone (GH) from salmon, common carp, grass carp and silver carp. Transgenic carps carrying human growth hormone gene have been produced. Antifreeze gene has also been identified and used for improving the antifreeze ability of Tilapia. Successful cryopreservation of fish sperm, involving eight species has been established in China.
India, with a coastline of 7 512 km has 2.02 million kmē of Exclusive Economic Zones, 4.7 million hectares of identified freshwater areas, and 1.7 million hectares of brackish-water areas. Its annual production of fish is around 4 million tonnes, half of it from aquaculture, and there is ample scope for enhancing fish production in the country. To supplement the fish feed resources, the use of bacterial cells as larval fish feed and processed aquatic plants as grow-out feed has been tested with success in India (Ayyapan, 1988).
In Japan, chromosomal manipulation and modern biotechnology are being widely applied to improved fish production. Gynogenesis, artificial sex reversal and induced polyploidy are being routinely used for increasing productivity as well as the quality of fish. The growth hormone of salmon and yellowtail is being mass produced through transgenic bacteria and used as a growth promoter on other fish such as rainbow trout. In the field of transgenic fish, the introduction and manifestation of the crystalline genes of chickens into killifish embryos were successfully achieved in 1986 at Kyoto University (Yamauchi, 1989). Other useful genes are being identified and introduced into commonly used fish species. New vaccines are also being developed to treat fish diseases. As regards fish feed, the development of microparticulate diets for larval fish to replace live foods in hatcheries is a major achievement. Mass production of ayu and carp fry in Japan with such diet formulates has been successful (Kanazawa, 1986).
Malaysia has a relatively long coastline, stretching for about 4 334 km and its marine resources contribute about 9.5 percent of the total value added in the agricultural sector; production has been increasing at a high annual growth rate of about 8 percent over the past decade. Moreover, the industry employs about 120 000 fishermen. The country clearly sees the scope for the application of biotechnology in fish production through genetic improvement of cultured fish, disease resistance and improved growth rate. Yet there is a gap in absorption or diffusion of the proven technologies. Besides fish, marine algae are now recognized as important resources for the production of valuable chemicals in Malaysia and local species of marine macroalgae (seaweed) are being screened for valuable chemicals. Some of the species studied and their products include: Gracilaria changii for agar and Turbinaria conoides, Sargassum baccularia and Sargassum siliquosum for algiric acid and antimicrobial compounds.
Singapore considers its marine bioresources as one of the most important and the government is highly supportive of the marine biotechnology venture. The National University of Singapore (NUS) is playing a leading role in this direction. Its Bioprocessing Technology Unit, established in 1990, concentrates on two main areas: fermentation and cell culture; and the isolation, separation and production purification technology. In addition, the Unit also supplies to specific users, especially synthesized antibodies for immunobiological assays and analyses, and custom-made digonucleotide primers for nucleic acid research. In 1992, the NUS and the Economic Development Board (EDB) established a Bioscience Centre in the University, with the following objectives: (i) to provide a multiuser central facility for biotechnology, (ii) to serve as a vehicle for collaborating with industries and other institutions in Singapore or abroad, in areas of common interest, and (iii) to provide training in biotechnology. The areas of research of the Centre are: bioactive compounds from marine organisms; toxins and venoms research; plant bioactive products; and products from microorganisms. Other related new establishments are the Centre for Natural Product Research and the Centre for Medical Informatics.
The Reef Ecology Study Team of the Department of Zoology in NUS is actively surveying the distribution of the various reef organisms and the Bioscience Centre is screening organisms for antifouling, antibacterial, antitumour, antiviral, antifungal, anti-inflammatory and insecticidal compounds. Antibacterial compounds are being isolated and characterized from horseshoe crabs. Biological properties and potential therapeutic application of toxins and other bioactive compounds in two marine species, namely the "Thunder Crab" (Lyphozozymus pictor) and the stonefish (Sysanceja horrida), have been studied. In addition, a few bioactive compounds have been purified from five local sea anemone species. These include a cytolysin, a trypsin inhibitor and two putative neurotoxins. Transgenics are also being attempted in a few fish species such as Marble Goby, grouper and salmon. The Marble Goby growth hormone gene has been cloned. NUS scientists are now in the process of combining this gene with a heterologous promoter to make a gene construct for transgenesis. Aquaculturists have been advised of the applications of (i) thyroid hormones in enhancing embryo and fry development; and (ii) gonado-tropin releasing hormones to help induce yolk formation and spawning. The hormones are being encapsulated into synthetic capsules for commercial use. Immunologists are studying the immune responses in fish and are developing various disease control methods, including vaccination with attenuated disease agents to develop antibodies.
Singapore is one of the major exporters of tropical aquarium fishes in the world. The DAN fingerprinting technology is being used to identify proper breeder stocks to be used in breeding programmes to maintain the quality and health of the fishes.
Aquaculture is most developed in Thailand. A Marine Biotechnology Unit (MBU) was established jointly by the National Centre for Genetic Engineering and Biotechnology and Aquatic Resources Research Institute of Chulalong Korn University in 1987. The Unit has been screening algae strains for feed purposes. Using cloned mitochondrial DNA, RFLP patterns of giant freshwater prawns (Macrobrachium rosenberghi) were studied for analysing variation patterns to design appropriate breeding plans. Studies are in progress to manipulate the Gonad Inhibiting Hormones (GIH) for regulating the growth, maturity and reproductive success of prawns.
To control the most common and yield-reducing disease, vibriosis, caused by the bacteria Vibrio anguillarum, of the widely cultured fish seabass, vaccines have been developed. Chromosome manipulation of oyster has also been standardized. Studies on the gametogenic cycle of Thai abalone (Haliotis ovina) are proving helpful for resource regulation and management, and for broadstock conditioning, induction of spawning, control of mating and seed production for land-based production. An outdoor mass culture of benthic diatom, Navicula sp., as a food source of abalone spot was also standardized recently.
Research on marine natural products in Thailand began a few years ago and provides valuable information on the structures and potential applications of the compounds and their derivatives from Thai sponges. Such information could be, apart from the bioactivities of the compounds that can possibly be applied further to pharmaceutical use, helpful in the chemotaxonomy of Thai sponges. The use of seaweeds as a source of phycocolloids is being promoted. The Biopolymer Research Unit (BU) of the Srinakarinwirot University, established in 1987, has developed a simple and low-cost technique for agar extraction from Gracelaria sp. seaweeds which could be applied at the village level. By developing and using chitin filter medium, the technique has improved the quality of the agar produced. The chitin could also be changed to chitosan, another valued product that is biodegradable and nonpolluting and can be used as a binder in recycling paper. This technology changes the shrimp wastes into more value-added products. The Unit is currently operating a project entitled "Technology Development of Shrimp Shell Processing". Other work relates to the development of biomembranes, copolymer membrane and biobeads. Another value-added product is a fluorescence pigment of R-phycoerythrin for protein markers.
The Marine Biotechnology Centre at Burapha University is concentrating on population dynamic studies of phytoplankton and zooplankton and identification of new pharmaceuticals from marine organisms. From the various species screened, the Centre found that 21 marine species had shown some degree of antimicrobial action. Twenty-three extracts from seven species had shown positive results when subjected to haemolytic testing against erythrocytes of 21 species. From the above, it can be seen that the following biotechnology-related research work on marine organisms is in progress: studies on bioactive metabolites from Thai sponges, isolation of pure culture of some marine microalgae, isolation of pure culture of some marine bacteria, and the use of microalgae in biological control of marine animal diseases.
While considerable progress has been made in fish biotechnology in Asia, the following aspects need to be further strengthened (Guerrero, 1991):