| 英文摘要 |
Abstract of "Develo[ment of algae and shellfish aquaculture and evaluation of their carbon fixation": 1. "Field Studies of Seaweeds Aquaculture that Can Be Promoted in Taiwan" : Continue the development of suitable seaweed species for aquaculture and utilization in Taiwan. In this year's project we will establish a pilot plant of Bangia Conchocelis culture system in the abandoned abalone cultur ponds; 2. establish a sucessful example of long line and pond suspension aquaculture of Grateloupia; 3. shift the original plan of Okinawa mozuku aqualcultue into Hinksia michelle pond culture; 4. Pond culture of thalloid Agardhiella subulata. Regarding the nutrient feeding mode of Bangia filamentous pond culture, we observed the lower and more fluctuating growth than that in photobioreactor under controlled temperature and consistent illumination. It is due to the changing of sun light intensities and temperature during the day. It was also noted that with the same reason the culture density never got the expected densities in culture chamber. Nutrient feeding should be applied by small increments in separated weeks rather than applied in one batch. By doing this method, not only contamination can be eliminated but the over accumulation of nitrate in produce can be prevented. Regarding the application of deep ocean water, the only needed is the low temperature of it to lower the water temperature during summer season. To obtain a high density of culture, we still have to add the recipe nutrients. There will be nothing to do with the water contents. What we need is an investment of a cooling green house to have a year round production. Regarding the Grateloupia seedlings, we have successfully developed two 1 m x 1 m nets of seedling and grew them in pond with running water without a canopy. With sufficient running water and aeration, the 1N gametophyte seedlings can grow to reach the market size of more than 20 cm long after 4 months. Offshore test of the seedling nets was not possible due to the short of budget for transportation and manpower. The growth of gametophytes stopped and started to decline while summer comes. The attachment of 2N sporophyte on ropes or other substrates were not successful due to the small crust discs they formed. However the detached seedlings can still grow and reach the market size in suspension inside the tank. The sporophytes grew continuously during summer in contrast to gametophytes, but with a slower growth rate. Nutrient enrichment enhanced the epiphytes growth and retard the growth of seedlings. The amount of seedlings produced in this period were not enough to perform the running water comparison, but the expected one 20 tons culture was reached. Regarding the brown filaments Hincksia culture, 360 L indoor photobioreactor has been successfully performed routinely. However due to the harsh environment outdoors, the expansion of culture size failed in several trials. Regarding Agardhiella’s culture in pond has also been successful. The growth of Agardhiella was much better in running water mode than stop water mode, even the stop water mode had nutrients enriched. Higher replace ratio of running water showed better growth. It was speculated that the nutrient and carbon dioxide supply in running water were the main cause of the different growth, but the best replace ratio of water for the growth of Agardhiella is not known yet. The cost for four different types of algae have been analyzed. The Bangia and Hincksia filamentous culture needed a lot of manpower in cleaning the ponds and harvesting in addition to the machines for harvesting. So the cost of filamentous culture will be 3000NT/kg dry powder, that means 500NT/kg wet filaments plus drying operation cost. The Hincksia filamentous culture will be costly, about double of the cost in dealing with Bangia, 6000NT/kg. The culture of Agardhiella and Grateloupia are still below the market size, and the mixing system is not well designed, the estimation of cost is not reasonable at this moment. If they were cultured in an open sea the cost will be the labor of tying the fragments on rope. If by tank culture, the cost will be on the replace ratio of water, the higher ratio, the higher growth rate, but more cost. Regarding the technology demonstration, we took the business matching demonstration and exhibition to the industry investors, rather than the fishermen, including the presentation of “Inland Culture of Filamentous Seaweed for the Source Material of Nutraceutical and Biomedical Products” at Kaoshiung on April 11, and the “Culture of Functional Seaweed for Food Supplement through Tissue Culture and Seedling Development” on June 6. We also participated the Taiwan Academic Research Expo 2013 to show our products and technologies. Finally we have succeeded a spin-off contract with Ray-In Biotechnology Ltd. Co. on the development of nutraceutical and pharmaceutical source material from red and brown algal aquaculture. 2. "Development of Aquacultural Techniques for the Algae and Molluscan after the Screening and Evaluation for their High Carbon Fixation" : There are four major topics of this project: 1. to identify the optimal growth conditions of the parameters, such as temperature, salinity, light intensity and light period for the culture of the Conchocelis phase of Bangia atropurpurea and Porphyra angusta and the tissue filaments isolated from the pith Grateloupia taiwanensis and Halymenia ceylanica, some of the edible red seaweed species common in Taiwan and determine the best species fit the development of algal aquaculture industry; 2. to identify the effects of light intensity and nitrogen nutrient enrichment on the growth and algal pigment compositions of Hincksia mitchelliae in order to evaluate the possible industrial production of fucoxanthin or the source material in Taiwan; 3. to import the Okinawa mozuku, Cladosiphon okamuranus and learn to control the development of various phases in its life cycle, and eventually develop its industrial production; 4. to compare the carbon fixation rates of these species under study. Among the above mentioned filamentous culture four edible red algal species, we found the environmental preferences of these four algae can be divided into two categories according to their origin of Conchocelis phase or filament tissue. All of these four species preferred the temperature of 20~25℃ but Grateloupia and Halymenia had better performance. It was also noted that Bangia survived better than the other three species at temperature above 30℃. More surprisingly Grateloupia also tolerates the low temperature, as 15℃in contrast to Bangia. Generally, under optimal temperature and not too high intensity of light, such as ＜9,000 Lux, the longer illumination means better growth to all species tested. Different species had slight difference in response to the light. Euryhaline species, such as Grateloupia and Bangia that can grow at 15‰ as normal as in natural seawater, in contrast to Halymenia and Porphyra. Regarding Hincksia mitchelliae, it was found that its growth was significantly affected by the light illumination, stronger the light intensity, higher the average weight gain. Both fucoxanthin and chlorophyll a contents decrease accordingly to the increase of light intensity, but the ratio of fucoxanthin to chlorophyll a increased along with the increasing of light intensity. We also observed that there were no significant difference in growth performance, neither the ratio of carotenoids to chlorophyll a of the alga under the treatment of various nitrate concentration (0~) in a period of eighteen days. It was speculated that fucoxanthin play a role in Hincksia, a photosynthetic accessory pigment but also an antioxidant in preventing the light stress. Spores released from the Cladosiphon okamuranus thalli which the live specimen was collected from Ryukyu have been isolated and cultured for the observation of the various phases in its life cycle. Currently several flasks of the spore and germinated filaments are maintain in the lab for further studies relating the growth requirements. In addition, carbon contents of the above mentioned filaments of the fast growing specimen have been analyzed and calculated for their carbon fixation rates. The slow growing filaments of Porphyra and Bangia which has the least crop harvested has the lowest carbon fixation rate, 7.8 and 16.34 mg/L/day respectively, instead, Grateloupia and Halymenia showed a higher growth rate and rich harvest had higher carbon fixation rates, 34.34 and 25.45 mg/L/day, respectively. Hincksia has a good carbon fixation rate as fast-growing red algae with the highest rate of 33.24 mg/L/day under 14 hr illumination period per day. However, continuous illumination of 24 hr per day had lower carbon fixation rate of 26.04 mg/L/day. It is obvious that the growth and carbon fixation of either brown or red filamentous algae are farther below the unialgal activity (1%). |
