• 유기물자원화
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• 제9권1호
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• pp.49-55
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• 2001

남은 음식물을 갈아 액상으로 만든 기질을 이용하여 생효모를 함유한 생균제제사료(probiotics)를 생산하기 위해 효모의 호기적 액상발효를 시도하였다. 기질의 영양조성의 최적화를 위해 미리 진탕배양한 결과를 토대로 액상의 남은 음식물 기질에 우레아($0.5g/{\ell}$), 당밀($4g/{\ell}$), O-phosphate($0.4g/{\ell}$), yeast extract($1g/{\ell}$)를 첨가하여 2리터 용량의 발효기를 이용하여 Kluyveromyces marxianus와 Aspersillus. oryzae를 접종하여 통기발효 시킨 결과 12시간 내에 $1.4{\times}10^{10}/liter$의 생균효모농도를 얻을 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권1호
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• pp.103-112
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• 1994

This study was a sequential experiment consisting if feeding trial and in vitro culture studies. Feeding was conducted by $2{\times}2{\times}2$ factorial design with two cimaterol levels (0, 0.25 mg/kg), two energy levels (3,200, 2,900 ME kcal/kg) and two sexes. In starting period (0-21 days) broilers were fed diets containing two energy level without dietary supplementation of cimaterol. During finishing period (21-42 days) cimaterol groups were fed cimaterol supplemented diets. In vitro cultures were carried out to study the cellular metabolism of protein and fat in liver and adipose tissues prepared from chicks used in feeding trials. Body weight gain was significantly improved by the administration of cimaterol to experimental diets by 2.4% (p < 0.05). Feed intake was reduced by cimaterol administration at the high energy level, but this trend was reversed at low energy level. Feed efficiency was improved by cimaterol administration and at high energy level the difference (5.7%) was significant(p < 0.05). The administration of cimaterol had no effects on percentage of abdominal fat content, giblet and neck. There was little difference in carcass yield between control and cimaterol treated group. The administration of cimaterol had no effects on nutrient metabolizability or carcass composition. The results of in vitro studies with liver tissues showed that cimaterol increased the lipolytic activities (p < 0.05) and decreased lipogenic activities (p < 0.05). In in vitro studies with acinar cell of liver tissues. cimaterol increased the amount of retained protein and decreased secreted protein at high energy level. but the trend was opposite at low energy level.

• 한국미생물·생명공학회지
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• 제21권4호
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• pp.354-365
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• 1993

A novel control method with automatic tuning of PID controller parameters has been developed for efficient regulation of dissolved oxygen concentration in fed-batch fermentations of Escherichia coli. Agitation speed and oxygen partial pressure in the inlet gas stream were chosen to be the manipulated variables. A heuristic reasoning allowed improved tuning decisions from the supervision of control performance indices and it coule obviate the needs for process assumptions or disturbance patterns. The control input consisted of feedback and feedforword parts. The feedback part was determined by PID control and the feedforward part is determined from the feed rate. The proportional gain was updated on-line by a set of heuristics rules based on the supervision of three performance indices. These indices were output error covariance, the average value of output error, and input covariance, which were calculated on-line using a moving window. The integral and derivative time constants were determined from the period of output response. The specific growth rate was maintained at a low level to avoid acetic acid accumulation and thus to achieve a high cell density. The specific growthe rate was estimated from the carbon dioxide evolution rate. In fed-batch fermentation, the simutaneous control of dissolved oxygen concentration (at 0.2; fraction of saturated value) and specific growth rate (at 0.25$hr^{-1}$) was satisfactory for the entire culture period in spite of the changes in the feed rate and the switching of control input.

• 한국초지조사료학회지
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• 제27권1호
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• pp.67-76
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• 2007

The conclusion of free Trade Agreement between South Korea and USA can become a serious threat to the Korean agriculture. On the strategic scheme the foodstuffs is the basis for protection of the state sovereignty. The Amur oblast of Russian Federation is region, which can supply South Korea cheap and good qualitative feeds. It means South Korea should create agricultural cooperation with the Amur oblast of Russian Federation with the purpose to begin organic agriculture in this area and it will help South Korea to counteract a quantitative attack on Korea from the side of american agricultural production. In the Amur oblast there are following fodder crops; Alfalfa, Smooth brome grass (gromus adonis L.), Siberian couch grass, Sudan pass, Colza rape (Brassica napus) and Amaranth (Avfranthus). In the same area also exist oatmeal, wheat, corn and barley, which is possible to use for feeds. All these above written cultures are cultivated organically, therefore it is possible to use them as organic forages in South Korea. It is very important to know system of crop rotation in the Amur oblast. There is a scheme of crop rotation, which is connected with increase and preservation of fertility of soil, maintenance of growth of productivity of agricultural cultures and reception of high-quality production. It is necessary to begin organic agriculture in a southern part of Amur oblast, where, in 2001 year, 97% of all sowing areas was concentrated. The acidity degree of soil in this part is not high ($ph5.1{\sim}5.5$), therefore does not require liming.

• 대한수의학회지
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• 제50권2호
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• pp.85-91
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• 2010

The large amount of tissue culture medium (TCM), which contains some of the active secretory components of Korean wild ginseng (KWG; Panax ginseng) such as saponins, is usually discarded after harvest of KWG. The present study was aimed to investigate the efficacy of oral administration of the TCM-KWG on growth performance and diseases resistance in broiler chickens. A day old broiler chickens randomized in 6 groups (n = 60/groups) were administered orally with 0, 2, 4, 8, 16 and 32 mL/L TCMKWG through drinking water for 5 weeks and examined the change of weight gain, feed intake and blood components. Also, five weeks old broiler chickens (n = 15/groups) were challenged orally with Salmonella (S.) gallinarum and investigated the mortality in broiler chickens. An average weight gain and feed intake significantly didn't change in TCM-KWG administration groups as compared to control group. The concentration of calcium (Ca), phosphate (Pi) and potassium (K) in serum were increase by TCM-KWG administration in broiler chickens. We also found that oral administration of TCM-KWG through drinking water significantly reduced the mortality in broiler chickens experimentally infected with virulent S. gallinarum. The results of this study indicated that TCM-KWG administration may elevate the resistance on disease and improved the skeleton formation and body homeostasis of chickens, and TCM-KWG can be used as a cost-effective and environmentally alternative additives to control of the disease and growth.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.1-11
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• 2014

The Kenyan aquaculture sector is broadly categorized into freshwater aquaculture and mariculture. Whereas freshwater aquaculture has recorded significant progress over the last decade, the mariculture sector has yet to be fully exploited. The Kenyan aquaculture industry has seen slow growth for decades until recently, when the government-funded Economic Stimulus Program increased fish farming nationwide. Thus far, the program has facilitated the alleviation of poverty, spurred regional development, and led to increased commercial thinking among Kenyan fish farmers. Indeed, national aquaculture production grew from 1,000 MT/y in 2000 (equivalent to 1% of national fish production) to 12,000 MT/y, representing 7% of the national harvest, in 2010. The production is projected to hit 20,000 MT/y, representing 10% of total production and valued at USD 22.5 million over the next 5 years. The dominant aquaculture systems in Kenya include earthen and lined ponds, dams, and tanks distributed across the country. The most commonly farmed fish species are Nile tilapia Oreochromis niloticus, which accounts for about 75% of production, followed by African catfish Clarias gariepinus, which contributes about 21% of aquaculture production. Other species include common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, koi carp Cyprinus carpio carpio, and goldfish Carassius auratus. Recently, Kenyan researchers have begun culturing native fish species such as Labeo victorianus and Labeo cylindricus at the National Aquaculture Research Development and Training Centre in Sagana. Apart from limited knowledge of modern aquaculture technology, the Kenyan aquaculture sector still suffers from an inadequate supply of certified quality seed fish and feed, incomprehensive aquaculture policy, and low funding for research. Glaring opportunities in the Kenyan aquaculture industry include the production of live fish food, e.g., Artemia, daphnia and rotifers, marine fish and shellfish larviculture; seaweed farming; cage culture; integrated fish farming; culture of indigenous fish species; and investment in the fish feed industry.

• 한국미생물·생명공학회지
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• 제16권6호
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• pp.450-456
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• 1988

대장균 변이주를 이용한 L-트립토판의 최적생산을 위해 목적산물의 생산과 유기산의 생성과의 상호관계를 조사한 결과 비 산생성속도(specific acid production rate)가 증가할수록 L-트립토판의 생산이 감소하는 것으로 나타났다. 따라서 L-트립토판 발효시 산의 생성량을 줄이기 위해 조절식 유가배양법을 도입하였는데 이 배양공정에서는 배양액내의 용존산소농도에 따라 영양배지의 유가속도를 조절하는 방식을 사용하여 세포증식속도를 제한, 세포의 산소요구량이 공급량을 초과하지 않도록 하였다. 이러한 조절식 유가배양법으로 대장균 세포를 배양한 결과 기존의 유가배양식에 비해 비 산생성속도가 현저하게 감소하였으며 L-트립토판의 생산은 5배 정도나 증가되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권2호
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• pp.230-240
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• 2016

Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a $3{\times}4$ factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, $0.25{\times}10^7$, $0.50{\times}10^7$, and $0.75{\times}10^7$ colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen ($NH_3$-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The $NH_3$-N concentration and $CH_4$ production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be $0.25{\times}10^7$ cfu/500 mg substrates in vitro.

• Asian-Australasian Journal of Animal Sciences
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• 제11권2호
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• pp.196-200
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• 1998

The proximate composition of viscera of six fish species viz., Catla catla, Labeo, rohita Cirrhina mrigala, Hypophthalmichthys molitrix, Ctenopharyngodon idella and Cyprinus carpio under the influence of artificial feed $(T_1)$, broiler manure $(T_2)$, buffalo manure $(T_3)$, N:P:K (25:25:0 $T_4$) and control pond $(T_5)$ has been studied on final harvest after the end of experimental period of one year. The overall comparison of six fish species under five different treatments showed that Cyprinus carpio remained the best for visceral total protein contents. The maximum visceral protein content was recorded in fishes under $T_2$ except Cirrhina mrigala, while the minimum under $T_5$. The comparison of five treatments showed that maximum (6.69) percentage of fat in viscera of fish was recorded under $T_2$, closely followed by $T_4$ while minimum (4.89) under the effect of $T_5$. Among the six fish species under five treatments Cyprinus carpio showed maximum accumulation/deposition of total fats in viscera.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.1011-1014
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• 2003

The objective of this work was to evaluate a thermotolerant yeast Issatchenkia orientalis DY252 as a microbial feed additive for ruminants. In the present study, the influence of volatile fatty acids (VFA) and temperature on oxygen uptake rate by I. orientalis DY 252 was investigated. It was evident that the oxygen uptake rate was decreased gradually as the VFA concentrations increased in a range of 30 to 120 mM. Although the oxygen uptake rate was not greatly affected by temperature in the range 37 to $43^{\circ}C$, a maximum value of $0.45mg\;O_2/g$ cell/ min was obtained at $39^{\circ}C$. With regard to the oxygen uptake rate by yeast, viability was found to be less important than the metabolic activity of yeast.