• 한국수산과학회지
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• 제37권1호
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• pp.7-12
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• 2004

This study investigated the possibility of salinity acclimation of freshwater rotifers (Brachionus calyciflorus) as live food for sweetfish (Plecoglossus altivelis) larvae, and also examined the optimal salinity for the growth of sweetfish. Freshwater rotifers cultured in 0 and 4 PSU and seawater rotifers (B. rotundiformis) cultured in 33 PSU were supplied to the larvae with four kinds of enrichment material (condensed freshwater Chlorella, $\omega-yeast,$ baker's yeast, Super Selco) and larval growth at 4 PSU was examined. Growth of the freshwater rotifers positively increased from 0 PSU to 6 PSU, but decreased when over 8 PSU was reached. Growth and survival of the sweet fish larvae reared in 0 PSU were significantly lower than those reared in either 4 PSU or 33 PSU. This indicated that the freshwater rotifers (B. calyciflorus) could be used as live food for sweetfish larvae reared in 4 PSU. The body weight of sweetfish larvae fed on freshwater rotifers enriched with Super Selco was the highest at 0.163 mg, but there was no significant difference in survival and body length of the fish fed with the other enrichment materials. The content of n-3 HUFA of the sweetfish larvae fed on the freshwater rotifers enriched with Super Selco and the condensed freshwater Chlorella was higher than that enriched with $\omega-yeast$ and baker's yeast. These results indicated that B. calyciflorus cultured with the condensed freshwater Chlorella could be used for the sweetfish larvae without enrichment, and the most efficient enrichment material for B. calyciflorus is Super Selco.

• Asian-Australasian Journal of Animal Sciences
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• 제25권5호
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• pp.665-673
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• 2012

A balance trial experiment was carried out to evaluate the potential relationship between an enzymatically hydrolyzed yeast (EHY) and yeast culture combined with a live Bacillus subtilis (Bs) on the productive parameters, ileal digestibility, retention of nutrient and energy and villus morphology in broilers. Seventy two 28 d old, Ross B308 male broilers were assigned to a factorial combination of 2 levels of EHY (0 and 1 kg/ton of feed) and 2 levels of Bs (0 and 125 g/ton of feed). The experiment lasted 2 weeks. Several treatment interactions were observed. EHY-fed broilers showed the lowest feed intake and feed conversion ratio whereas Bs-fed broilers showed the highest feed intake and intermediate feed conversion ratio (EHY and BS interaction, p<0.05). Also, EHY-fed broilers had greater ileal digestibility of dry matter (EHY and BS interaction, p<0.01) and energy (EHY and BS interaction, p<0.05) but these responses were counterbalanced by the combination of EHY and Bs. The thickness of the mucosa was similar between the control and EHY-fed broilers, but was lowest when Bs was added alone (EHY and BS interaction, p<0.01). The thickness of the villus was greater in EHY plus Bs-fed broilers, intermediate for the control and lower for Bs or EHY-fed broilers (EHY and BS interaction, p<0.05). The area of the villus was greater in the control and EHY plus Bs-fed broilers (EHY and BS interaction, p<0.05). In addition, EHY-fed broilers showed greater breast yield and nitrogen retention (p<0.01) and ashes digestibility (p<0.05). On the other hand, Bs-fed broilers had greater carcass and breast weight, nitrogen retention, energy excretion and villus height (p<0.05). In summary, EHY and Bs enhanced some growth, carcass and nutrient retention responses, but did not show any synergic relationship in these responses. Opposite to this, the results suggest that the positive effect of EHY on the feed conversion and digestibility of nutrients were counterbalanced by the addition of Bs.

• 한국수산과학회지
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• 제36권6호
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• pp.606-613
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• 2003

This study investigated the effects of food type (condensed freshwater Chlorella, dried Chlorella, dried Spirulina, dried Schizochytrium, baker's yeast and $\omega-yeast$) and amount, and supplementation of vitamin $B_{12}$ on the growth of freshwater rotifer (Brachionus calyciflorus) in high density culture. Growth of rotifers fed condensed freshwater Chlorella was the highest and its density ranged $7.65-8.14{\times}10^3\;inds./mL.$ The primary lipid acids of rotifers fed condensed freshwater Chloyella were linoleic and linolenic, and their amount ($\%$ of total fatty acids) were $48.8\%\;and\;26.8\%,$ respectively. This suggests that condensed freshwater Chlorella would be an effective diet for high quality and quantity rotifers, which in turn serve as live food for freshwater fish larvae. Growth rate of rotifers with Chlorella supplementation increased as amount of supplementation increased up to 1.5 and 2.5 mg at 28 and $32^{\circ}C$, respectively. However, undissolved ammonia toxicity and packing volume of Chlorella in culture medium, reached the optimal conditions for the stable and effective cultivation of rotifers when amount of condensed freshwater Chlorella was 1.5 mg in dry weight per 1,000 rotifers at $28^{\circ}C\;and\;32^{\circ}C$ Growth of rotifers in condensed freshwater Chlorella with vitamin $B_{12}$ supplementation was significantly higher than that of rotifers without supplementation. However, no significant difference was found among the different concentrations of vitamin $B_{12}.$ Therefore, vitamin $B_{12}$ could improve the growth of rotifers (B. calyciflorus).

• 한국식생활문화학회지
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• 제25권2호
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• pp.207-215
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• 2010

The purpose of this study was to investigate the microbiological characteristics and antioxidant activity of tomato sauce in terms of the variety of herbs that have been widely used in Western cuisine. As storage time increases, the number of total microbes changes, but the bacteria count was in the range of $1.0{\times}10^1-2.1{\times}10^2$, which did not increase much over 60 days of storage. The reason seems to be that the amount of heat treatment undergone by this type of sauce type, and its acidity make for difficult conditions for microbes to live. Yeast and mold measurements showed that yeast and mold were not detected for up to 30 days of storage in the tomato sauce with various types and amounts of added herbs. After 45 and 60 days, the yeast and mold count was in the range of $1.0{\times}10^1-8.5{\times}10^1$, and the same in the control. Measurements of phenolic compounds in 60 days of storage showed that tomato sauce with different types and amounts of added herbs had the lowest amounts relative to the control for all storage periods. The more herbs that were added, the higher the phenolic compounds resulted. As storage times increase, the phenolic compounds showed a tendency to decline. The DPPH radical scavenging effects of the tomato sauce herbs added showed a tendency to increase antioxidant activity when more herbs were added. The microbiology results of the storage test of tomato sauce with added herbs showed that the amount of microorganisms in tomato sauce with added herbs did not increase much in 60 days of storage at $4^{\circ}C$. The amount of microorganisms was small, so tomato sauce with added herbs can be used for 2 months with refrigeration.

• Asian-Australasian Journal of Animal Sciences
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• 제29권2호
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• pp.211-218
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• 2016

This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at $39^{\circ}C$ for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD.

• 한국가금학회지
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• 제29권3호
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• pp.205-211
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• 2002

본 연구는 산란계에 대한 생효모 첨가효과를 구명하기 위하여 실시되었다. 21주령 ISA Brown 160수를 공시하여 9주 동안 사양하면서 산란생산성, 영양소 소화율, 회장 및 맹장내 미생물, 계란 품질 및 계분내 암모니아 가스발생 양상을 조사하였다. 첨가된 생효모는 Pichia farinosa SKM-1였으며, g당 $10^{6}$ cfu를 함유한 건조 생효모를 사료에 4수준 (0, 0.1, 0.3 및 0.5%)으로 첨가하였다. 각 처리는 반복당 10수씩 4반복으로 하였다. 산란율은 생효모 0.1 및 0.3%첨가구가 무첨가구에 비하여 유의적으로 증가하였으며(P<0.05), 평균난중은 처리간 차이를 보이지 않았다. 1일 산란량은 0.3% 첨가구가 다른 처리에 비하여 가장 높게 나타났다(P<0.05). 사료섭취량은 생효모 첨가구가 무첨가구에 비하여 약간 적었으나 유의성은 없었다. 난생산 사료효율은 0.3% 생효모 첨가구가 다른 처리구들에 비하여 유의하게 개선되었다(P<0.05). 건물, 조단백질, 조지방 및 조회분 소화율은 생효모 첨가에 의해 영향을 받지 않았다. 계란 품질은 25주령에는 0.3% 첨가구에서 산란율이 높았던 관계로 난각질이 유의하게 떨어졌으나, 29주령에서는 다시 개선되는 결과를 보였다. 회장 내 유산균은 생효모 첨가에 의해 증가하는 것으로 나타났으며, 효모와 혐기성 미생물은 차이가 없었다. 맹장내 미생물은 처리간에 비슷하게 나타났다. 계분내 암모니아 가스 발생량은 배분 후 3일차부터 6일차까지 최대로 발생하였는데, 이 시기에 생효모 첨가구가 무첨가에 비하여 발생량이 유의하게 감소하는 것으로 나타났다. 이상의 결과에서 산란계에 대한 효모Pichia의 첨가는 산란 생산성을 향상시키고, 암모니아 가스 발생량을 감소시킬 수 있었으며 경제성을 고려한 적정첨가수준은 0.1%수준으로 나타났다.

• Journal of Microbiology
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• 제44권4호
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• pp.439-446
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• 2006

In this study, the growth kinetics of Lactobacillus rhamnosus and lactic acid production in continuous culture were assessed at a range of dilution rates $(0.05 h^{-1}\;to\;0.40h^{-1})$ using a 2L stirred tank fermenter with a working volume of 600ml. Unstructured models, predicated on the Monod and Luedeking-Piret equations, were employed to simulate the growth of the bacterium, glucose consumption, and lactic acid production at different dilution rates in continuous cultures. The maximum specific growth rate of L. rhamnosus, ${\mu}_{max}$, was estimated at $0.40h^{-1}$I, and the Monod cell growth saturation constant, Ks, at approximately 0.25g/L. Maximum cell viability $(1.3{\times}10^{10}CFU/ml)$ was achieved in the dilution rate range of $D=0.28h^{-1}\;to\;0.35h^{-1}$. Both maximum viable cell yield and productivity were achieved at $D=0.35h^{-1}$. The continuous cultivation of L. rhamnosus at $D=0.35h^{-1}$ resulted in substantial improvements in cell productivity, of 267% (viable cell count) that achieved via batch cultivation.

• 한국수산과학회지
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• 제33권2호
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• pp.164-170
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• 2000

Rotifer의 대량배양에는 해산 chlorella가 가장 적합하나 비용이 높고, 유지효모는 경제적이 긴 하나 먹이효율이 낮은 문제점이 있다. 이와 같은 문제점을 개선하기 위하여 본 연구에서는 광합성세균 (Rhodopseudomonas capsulata)의 첨가 효과를 조사 하였다. Rotifer 한 개체당 1일 먹이량으로 10,000, 50,000, 100,000, 200,000, 300,000세포의 Chlorella ellipsoidea를 공급하고 각 chlorella 수의 10, 20, 30배의 광합성세균을 첨가한 결과 200,000세포에 광합성 세균 20배 ($4{times}10^6 cell$)를 공급한 것이 가장 성장이 높았으나 경제적인 측면에서는 chlorella 100,000세포에 광합성세균 30배를 공급하는 것이 더 효과적이었다. 또, rotifer 1개체당 1일 먹이량으로 유지효모를 100,000, 200,000, 300,000세포를 공급하고 각 유지효모 수의 10, 20, 30배의 광합성세균을 첨가한 결과 200,000세포에 광합성세균 20배를 첨가한 실험구에서 rotifer의 성장이 가장 높았다. Chlorella와 유지효모를 각각 200,000 세포씩 그리고 chlorella와 유지효모에 광합성세균을 20배의 농도로 첨가하여 rotifer를 배양하여 넙치 자어를 사육한 결과 chlorella에 광합성세균을 첨가한 실험구의 생존율이 $96.8{\%}$로 가장 높았으며 성장의 경우도 광합성세균을 첨가한 실험구에서 높은 경향을 보였다. 또 광합성세균을 첨가한 실험구에서의 넙치 자어는 총지질과 EPA와 DHA의 함량이 광합성세균을 첨가하지 쟈은 실험구에서보다 높게 나타났다. Artemia nauplius를 6시간동안 광합성세균으로 영양강화하여 넙치 치어를 20일간 사육한 결과 영양강화한 것은 하지 않은 것보다 생존율과 성장이 높았으며 광할성세균의 최적영양걍화농도는 $ml 당 2{times}10^7 cells$로 나타났다. Chlorella와 유지 효모에 광합성 세균의 첨가는 rotifer의 성장과 자치어의 생존율과 성장에 효과적이었다. 그러나 과다한 양의 광합성세균은 오히려 negative effect가 있는 것으로 나타났다.

• 한국수산과학회지
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• 제49권1호
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• pp.30-37
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• 2016

Microalgae are functional foods because they contain special anti-aging inhibitors and other functional components, such as ecosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-3 polyunsaturated fatty acids. Many of these functional dietary components are absent in animals and terrestrial plants. Thus, microalgae are widely utilized in human functional foods and in the feed provided to farmed fish and terrestrial livestock. Many marine organisms consume microalgae, often because they are in an appropriate portion of the cell size spectrum, but also because of their nutritional content. The nutritional requirements of marine organisms differ from those of terrestrial animals. After hatching, marine animals need small live forage species that have high omega-3 polyunsaturated fatty acid contents, including EPA and DHA. Euglena cells have both plant and animal characteristics; they are motile, elliptical in shape, 15-500 μm in diameter, and have a valuable nutritional content. Mixotrophic cell cultivation provided the best growth rates and nutritional content. Diverse carbon (fructose, lactose, glucose, maltose and sucrose) and nitrogen (tryptone, peptone, yeast extract, urea and sodium glutamate) supported the growth of microalgae with high lipid contents. We found that the best carbon and nitrogen sources for the production of high quality Euglena cells were glucose (10 g L^–1) and sodium glutamate (1.0 g L^–1), respectively.

• 한국양식학회지
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• 제18권1호
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• pp.52-59
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• 2005

본 연구는 Apocyclops royi를 양식에서 초기 먹이생물로 적용시키기 위해 이들의 대량배양을 위한 수온과 염분의 최적범위 및 최적 성장을 위한 먹이를 구명하고자 실시되었다. A. royi 성체 암컷의 총 nauplius 생산력은 수온 $32^{\circ}C$에서 188 개체로 가장 높게 나타났고 성체 암컷 당 일간 nauplius 생산수도 총 생산수와 같은 경향을 보여 $32^{\circ}C$에서 13.4개체로 가장 높게 나타났다. Nauplius 부화 후 최초 포란할 때까지 발달 기간은 $32^{\circ}C$가 7.2일로 가장 빠른 발달을 보였으며 수온이 감소할수록 발달기간이 느린 경향을 보였다. A. royi 성체 암컷의 총 nauplius 생산력은 염분 10 ppt에서 169 개체로 가장 높게 나타났고 성체 암컷 당 일일 평균 nauplius 생산수는 10 ppt가 9 개체로 가장 높게 나타났다. Nauplius 부화 후 최초 포란할 때까지 발달 기간은 10 ppt와 15 ppt이 각각 7.1일, 7.7일로 빠른 발달을 보였으며 염분이 높을수록 발달기간이 길어지는 경향을 보였다. A. royi 성체 암컷의 총 nauplius 생산력은 I. galbana와 T. suecica 공급구에서 각각 142, 127 개체로 가장 높게 나타났고, 성체 암컷 당 일일 평균 nauplius 생산수는 I. galbana 공급구가 8.2개체로 가장 높게 나타났다. Nauplius 단계에서 copepodid 단계까지의 발달 기간은 I. galbana, T. suecica, P. tricornutum 공급구가 각각 3.4, 3.6, 3.7일로 담수산 농축 Chlorella와 빵 효모 공급구보다 빠른 발달을 보였다. 결론적으로, cyclopoid 요각류인 A. royi는 대량배양의 잠재성이 있으며 최적 대량배양을 위해서는 수온 $32^{\circ}C$, 염분 10 ppt에서 먹이로 I. galbana를 공급하여야 할 것으로 판단된다.