• 한국해양환경ㆍ에너지학회지
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• 제15권2호
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• pp.133-141
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• 2012

한국 남해연안해역에서 분리한 유독와편모조류 $Alexandrium$ $tamarense$와 $Alexandrium$ $catenella$의 성장에 영향을 미치는 수온과 염분의 특성을 실내 배양실험을 통해 살펴보았다. 수온은 10, 15, 20, 25, $30^{\circ}C$의 5단계, 염분은 10, 15, 20, 25, 30, 35 psu의 6단계를 조합한 총 30단계의 조건에서 성장속도 변화를 관찰하였다. 최대성장속도를 보이는 수온과 염분은 $A.$ $tamarense$에서 $15^{\circ}C$와 30 psu, $A.$ $catenella$에서 $25^{\circ}C$와 30 psu로 나타났다. 또한 최적성장조건은 $A.$ $tamarense$에서 $10-20^{\circ}C$, 25-35 psu이고, $A.$ $catenella$에서 $20-30^{\circ}C$, 25-35 psu였다. 얻어진 수온과 염분의 조건을 이용하여 중회귀분석에 의해 예측 모델식을 계산한 결과, $A.$ $tamarense$는 ${\mu}=0.04+0.0193T-0.0339S-0.0005T^2+0.0021S^2+0.00073TS-0.000022T^3-0.000038S^3+0.00000086TS^2-0.0000255T^2S$이며, $A.$ $catenella$는 ${\mu}=1.01-0.1288T-0.0778S+0.0067T^2+0.0038S^2+0.00204TS-0.0001T^3-0.000059S^3-0.0000131TS^2-0.0000392T^2S$로 나타났으며, 예측값과 실험값 사이에는 높은 상관관계를 보였다. 본 연구결과는 수온과 염분의 현장관측 값을 이용하여 성장속도를 추정할 수 있기 때문에, $A.$ $tamarense$와 $A.$ $catenella$의 개체군 확대를 이해하는데 도움이 될것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1722-1727
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• 2006

The nutritive value of 4 straws, obtained after thrashing of seeds from fodder crops, was assessed as complete feed for ruminants. Sixteen male Murrah buffaloes (liveweight 365.8${\pm}$19.5 kg), were divided into 4 equal groups and offered ad lib. straw of either Trifolium resupinatum, Trifolium alexandrium, Medicago sativa or Lolium perenne, supplemented with minerals and vitamin A, for 40 days in a completely randomized design. Simultaneously, each straw was offered to 3 rumen fistulated male buffaloes in order to assess the biochemical changes in the rumen. Compared to other straws M. sativa straw had higher (p<0.05) organic matter (OM), crude protein (CP), acid-detergent fiber (ADF) and cellulose content. L .perenne had the highest (p<0.05) hemicellulose and lowest (p<0.05) CP and acid-detergent lignin (ADL) content. T. resupinatum had the lowest concentration of cell wall constituents (CWC). The digestibility of nutrients of T. resupinatum and L. perenne straw was similar, but higher (p<0.05) than that of other straws. M.sativa straw showed highest (p<0.05) digestibility of CP. The highest OM digestibility of T. resupinatum and CP digestibility of M. sativa were responsible for highest (p<0.05) total volatile fatty acids and trichloroacetic acid precipitable nitrogen in the strained rumen liquor. The digestible crude protein (DCP) was highest (p<0.05) in M. sativa followed by that in T. alexandrium. The total purine derivatives excreted in urine varied from 0.22-0.32 mmol/kg $W^{.75}/d$. The efficiency of microbial protein synthesis indicated that OM of straws of M. sativa and that of T. alexandrium was used more (p<0.05) efficiently. The microbial protein synthesized was highest in T. resupinatum, but statistically similar to other groups. The values for N-retention and apparent biological value were highest for L. perenne, though comparable with that of M. sativa and T. alexandrium. The available metabolizable energy (ME) was highest (p<0.05) in T. resupinatum followed by that in L. perenne and lowest in M. sativa. It was concluded that all the straws, supplemented with minerals and vitamin A, could be fed exclusively to adult ruminants with no adverse affect, as animals were able to maintain body weight (372${\pm}$20.1 kg).

• 환경생물
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• 제24권3호
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• pp.275-281
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• 2006

We examined effects of water temperature, salinity, irradiance, and different media on the growth of the toxic dinoflagellate Alexandrium tamarense (HYM9704), which was isolated from Jinhae Bay, Korea. The ranges of temperature and salinity in which the strain was able to grow were $10{\sim}20^{\circ}C$ and $20{\sim}34$ psu, respectively. These values were in accordance with those observed in situ. The maximum growth rates of axenic A. tamarense (HYM9704) was $0.25d^{-1}$ at $15^{\circ}C$, 30 psu, and $100{\mu}Em^{-2}s^{-1}$. The temperature affected the growth rates of axenic A. tamarense more significantly than the salinity. The type of culture media did not affect the growth rates of axenic A. tamarense. The strain in N-limited and P-limited media went into the stationary phase faster than that in T1 and T1/2 medium.

• 한국환경농학회지
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• 제31권2호
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• pp.175-184
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• 2012

우리나라뿐만 아니라 전 세계적으로 적조 및 마비성 패독을 일으켜 문제시되고 있는 유독성 와편모류인 A. catenella 를 살조시키는 해양미생물 Pseudoalteromonas sp. NH-12를 마산만의 적조발생 해역에서 분리, 동정하고 그 특성과 살조능에 대해 연구함으로써 보다 환경 친화적인 적조 구제 기술개발의 기초 자료를 제공하고자 하였다. 적조발생 해역인 마산만의 해수에서 분리한 38개의 해양미생물 균주 중 4종의 미생물이 A. catenella 에 대해 살조능을 나타내었으며, 이중 살조능이 가장 우수한 NH-12 균주를 선별하였다. 본 균주는 API kits 및 16S rRNA gene 염기서열을 분석하여 계통분류를 행한 결과 Pseudoalteromonas 속으로 분류되었으며, 최적 배양조건은 $25^{\circ}C$, pH 8.0, 3.0% NaCl 농도였다. Pseudoalteromonas sp. NH-12의 성장 단계별 살조능은 대수증식기 후기, 정지기, 대수증식기 중기, 유도기 순으로 높게 나타났다. 살조물질은 대수증식기 중기 이후에 활발히 생산되기 시작하여 대수증식기 후기에 가장 고농도로 축적되는 것으로 판단된다. 2조 배양계를 이용한 살조 유형 조사에서 Pseudoalteromonas sp. NH-12는 격리된 상태에서도 A. catenella 를 살조시켜 '직접 공격형'이 아니라 세포외로 물질을 분비하여 살조시키는 '살조인자 분비형'으로 확인되었다. 또한 NH-12 균주 배양여과액을 5% 첨가하였을 때 36시간 후에 A. catenella 는 100% 살조되었고, 10%를 첨가한 경우 24시간 후에 99% 이상 살조되었다.

• ALGAE
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• 제33권3호
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• pp.279-290
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• 2018

Microalgae have been utilized in diverse industries including aquaculture. Among the microalgae, dinoflagellates are known to have various bioactive compounds, and thus the interest in their application to industry has increased. In order to test their potential as food materials for aquaculture animals, the crude protein contents and compositions of amino acids of six dinoflagellates Heterocapsa rotundata (family Heterocapsaceae), Ansanella granifera (Suessiaceae), Alexandrium andersonii (Ostreopsidaceae), Takayama tasmanica (Brachidiniaceae), Takayama helix, and Gymnodinium smaydae (Gymnodiniaceae) belonging to diverse families were analyzed. The percentage of the amount of the crude protein relative to dry weight of T. tasmanica was the highest (65%) and that of A. andersonii was the lowest (26%). However, the highest percentage of total detected amino acids in crude protein was found in A. andersonii (98.2%). In all six dinoflagellates, glutamic acid was the most dominant amino acid in crude protein. However, the second main amino acid was aspartic acid for H. rotundata, A. granifera, T. helix, and G. smaydae, but were arginine and leucine for A. andersonii and T. tasmanica, respectively. Furthermore, T. tasmanica and T. helix did not have taurine and gamma-aminobutyric acid, whereas the other dinoflagellates possessed them. The percentages of essential amino acid contents of the dinoflagellates met the requirement levels for juvenile shrimps. In addition, the dinoflagellates were not toxic to the brine shrimp Artemia salina. Compared with the other microalgae reported so far, H. rotundata and A. andersonii can be used for arginine-rich diets, T. tasmanica for valine and leucine-rich diets, A. granifera for histidine-rich diets, T. helix for threonine-rich diets, and G. smaydae for lysine-rich diets. Therefore, based on their biochemical composition and toxicity to Artemia, the dinoflagellates could be used as essential amino acid sources for cultivating animals in the aquaculture industry.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1252-1261
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• 2008

Twenty-four yearling Boer$\times$Spanish goats were used in a crossover design experiment to determine effects of tethering on forage selection, intake and digestibility, grazing behavior and energy expenditure (EE) with forage high in nutritive value and low to moderate in mass. Objectives were to determine if tethered goats could be used as a model for study of unrestrained animals and to characterize tethering as a production practice. Four 0.72-ha pastures of wheat (Triticum aestivum) and berseem clover (Trifolium alexandrium) were grazed in December and January. Each pasture hosted six animals, three with free movement and three attached to a 4.11-m tether for access to a circular area of $53.1m^2$. Tethering areas were moved each day. One animal of each treatment and pasture was used to determine forage selection, fecal output or grazing behavior and EE; therefore, there were eight observations per treatment. Mass of forage DM before grazing in Tethered areas averaged 1,280 and 1,130 kg/ha in periods 1 and 2, respectively. The CP concentration in ingesta was greater ((p<0.05) 239 and 209 g/kg; SE = 8.0) and the NDF level was lower (p<0.05) for Free vs. Tethered animals (503 and 538 g/kg; SE = 12.0); in vitro true DM digestion was similar between treatments (0.808 and 0.807 for Free and Tethered, respectively; SE = 0.0096). Intakes of DM (1,013 and 968 g/d; SE = 78.6), NDF (511 and 521 g/d; SE = 39.9) and ME (10.9 and 10.7 MJ/d; SE = 0.90) were similar between treatments, but CP intake was greater (p<0.05) for Free vs. Tethered animals (241 and 203 g/d; SE = 17.2). There were small treatment differences in in vivo apparent digestibility of OM ((p<0.05) 0.780 and 0.814; SE = 0.0049), CP ((p<0.05) 0.800 and 0.817; SE = 0.0067) and NDF ((p<0.09) 0.777 and 0.760 for Free and Tethered, respectively; SE = 0.0078). There were no treatment effects on time spent ruminating or grazing (346 and 347 min/d for Free and Tethered, respectively; SE = 42.5), but EE was considerably greater (p<0.05) for Free vs. Tethered animals (571 and 489 kJ/kg $BW^{0.75}$; SE = 8.9). In conclusion, with forage of high nutritive value and low to moderate in mass, tethering can offer a production advantage over free grazing of less energy used for activity despite similar grazing time. With forage removal considerably less than that available for grazing, effects of tethering on chemical composition of selected forage were small and less than needed to markedly affect digestion. Tethering may offer a means of studying some aspects of grazing by ruminants, but would not seem suitable for energy metabolism.