• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1511-1520
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• 2019

Objective: The present study was conducted to select a plant oil without inhibitory effects on rumen fermentation and microbes, and to determine the optimal supplementation level of the selected oil in a series of in vitro studies for dietary application. Then, the selected oil was evaluated in a feeding study using Thai crossbred beef cattle by monitoring growth, carcass, blood and rumen characteristics. Methods: Rumen fluid was incubated with substrates containing one of three different types of plant oil (coconut oil, palm oil, and soybean oil) widely available in Thailand. The effects of each oil on rumen fermentation and microbes were monitored and the oil without a negative influence on rumen parameters was selected. Then, the dose-response of rumen parameters to various levels of the selected palm oil was monitored to determine a suitable supplementation level. Finally, an 8-month feeding experiment with the diet supplemented with palm oil was carried out using 12 Thai crossbred beef cattle to monitor growth, carcass, rumen and blood profiles. Results: Batch culture studies revealed that coconut and soybean oils inhibited the most potent rumen cellulolytic bacterium Fibrobacter succinogenes, while palm oil had no such negative effect on this and on rumen fermentation products at 5% or higher supplementation level. Cattle fed the diet supplemented with 2.5% palm oil showed improved feed conversion ratio (FCR) without any adverse effects on rumen fermentation. Palm oil-supplemented diet increased blood cholesterol levels, suggesting a higher energy status of the experimental cattle. Conclusion: Palm oil had no negative effects on rumen fermentation and microbes when supplemented at levels up to 5% in vitro. Thai crossbred cattle fed the palm oil-supplemented diet showed improved FCR without apparent changes of rumen and carcass characteristics, but with elevated blood cholesterol levels. Therefore, palm oil can be used as a beneficial energy source.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1700-1705
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• 2018

We evaluated the influence of sampling technique (cannulation vs. stomach tube) and site (dorsal sac vs. ventral sac) on the rumen microbiome and fermentation parameters in Hanwoo steers. Rumen samples were collected from three cannulated Hanwoo steers via both a stomach tube and cannulation, and 16S rRNA gene amplicons were sequenced on the MiSeq platform to investigate the rumen microbiome composition among samples obtained via 1) the stomach tube, 2) dorsal sac via rumen cannulation, and 3) ventral sac via rumen cannulation. A total of 722,001 high-quality 16S rRNA gene sequences were obtained from the three groups and subjected to phylogenetic analysis. There was no significant difference in the composition of the major taxa or alpha diversity among the three groups (p>0.05). Bacteroidetes and Firmicutes represented the first and second most dominant phyla, respectively, and their abundances did not differ among the three groups (p>0.05). Beta diversity principal coordinate analysis also did not separate the rumen microbiome based on the three sample groups. Moreover, there was no effect of sampling site or method on fermentation parameters, including pH and volatile fatty acids (p>0.05). Overall, this study demonstrates that the rumen microbiome and fermentation parameters are not affected by different sampling techniques and sampling sites. Therefore, a stomach tube can be a feasible alternative method to collect representative rumen samples rather than the standard and more invasive method of rumen cannulation in Hanwoo steers.

• 한국초지조사료학회지
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• 제37권4호
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• pp.350-357
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• 2017

Near infrared spectroscopy (NIRS) is a rapid and accurate method for analyzing the quality of cereals, and dried animal forage. However, one limitation of this method is its inability to measure fermentation parameters in dried and ground samples because they are volatile, and therefore, respectively lost during the drying process. In order to overcome this limitation, in this study, fresh coarse haylage was used to test the potential of NIRS to accurately determine chemical composition and fermentation parameters. Fresh coarse Italian ryegrass haylage samples were scanned at 1 nm intervals over a wavelength range of 680 to 2500 nm, and optical data were recorded as log 1/reflectance. Spectral data, together with first- and second-order derivatives, were analyzed using partial least squares (PLS) multivariate regressions; scatter correction procedures (standard normal variate and detrend) were used in order to reduce the effect of extraneous noise. Optimum calibrations were selected based on their low standard error of cross validation (SECV) values. Further, ratio of performance deviation, obtained by dividing the standard deviation of reference values by SECV values, was used to evaluate the reliability of predictive models. Our results showed that the NIRS method can predict chemical constituents accurately (correlation coefficient of cross validation, $R_{cv}^2$, ranged from 0.76 to 0.97); the exception to this result was crude ash ($R_{cv}^2=0.49$ and RPD = 2.09). Comparison of mathematical treatments for raw spectra showed that second-order derivatives yielded better predictions than first-order derivatives. The best mathematical treatment for DM, ADF, and NDF, respectively was 2, 16, 16, whereas the best mathematical treatment for CP and crude ash, respectively was 2, 8, 8. The calibration models for fermentation parameters had low predictive accuracy for acetic, propionic, and butyric acids (RPD < 2.5). However, pH, and lactic and total acids were predicted with considerable accuracy ($R_{cv}^2$ 0.73 to 0.78; RPD values exceeded 2.5), and the best mathematical treatment for them was 1, 8, 8. Our findings show that, when fresh haylage is used, NIRS-based calibrations are reliable for the prediction of haylage characteristics, and therefore useful for the assessment of the forage quality.

• 한국미생물·생명공학회지
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• 제20권2호
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• pp.203-206
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• 1992

Demeclocycline 생산균주를 세포 융합하여 얻은 변이주를 이용하여 demethyltetracycline을 생산하기 위한 발효조건에 대해 연구한 결과, 발효 최적온도는 $25^{\circ}C$였고, 초기pH는 6.7였으며 발효기간 중 pH를 일정하게 조절하면 생산성이 저하되었다. 또한 식균량이 많을 수록 초기 당 소모와 점도가 높았는데, 이는 식균량이 증가함에 따라 발효가 급격히 진행됨을 나타냈다. 식균량은 5(v/v)일 때 생산성이 가장 높았으며 전배양 시간과 전배양 pH가 중요한 요인임을 밝혔다.

• 한국식품영양과학회지
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• 제28권4호
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• pp.760-765
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• 1999

Changes in physiochemical properties of Sunchang sikhe kochujang, the most famous traditional kochujang, by red ginseng addition(1, 2 and 5% red ginseng on the total weight basis) were investigated. Measurements of physiochemical parameters such as reducing sugar content, alcohol content, amino type nitrogen content and color difference value were conducted during fermentation at 25oC for 120 days. Alcohol content was increased from the begining of fermentation, reaching at the highest level after 90 days of fermentation and then slowly reduced. Alcohol content of red ginseng kochujang was generally higher than that of control kochujang after 90 days of fermentation. Crude protein content of control kochujang and red ginseng kochujang were reduced during fermentation whereas amino type nitrogen content were gradually increased during fermentation. Amino type nitrogen content of red ginseng kochujang appeared to be slightly lower than that of the control kochujang. The reduction in amino type nitrogen content of red ginseng kochujang was negatively related to the level of red ginseng addition. Among color difference values, L and b value of both control kochujang and red ginseng kochujang were reduced by 30 days from the begining of fermentation and then started to be increased.

• 한국초지조사료학회지
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• 제40권4호
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• pp.279-284
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• 2020

This study aimed to analyze ruminal fermentation, methane emissions, and methanogen levels for different forage feed type and concentrate feed ratios. Alfalfa hay, oat hay, and a feed concentrate were used for in vitro fermentation experiments, at ratios of 9:1, 5:5, and 1:9 (forage:concentrate). After 24 h of incubation, rumen fermentation and methanogen level changes were evaluated. In the low forage treatments, the total gas, CH4, NH3-N, true dry matter digestibility, and total volatile fatty acid were higher than the other treatments, which were used as the parameters on which to assess rumen fermentation (P < 0.05). The feed ratio influenced the copy number for the total archaea and the genus Methanobrevibacter (P = 0.015, P = 0.010). The copy number result trend was like that for CH4 per digested dry matter (DDM). The PCR results and methanogen copy number analysis indicated that the composition of the methanogens affected the CH4 levels, not their copy number. The results of this study can be applied to predict rumen fermentation and methane emission patterns for cattle fed a variety of feedstuffs.

• 동아시아식생활학회지
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• 제5권2호
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• pp.49-62
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• 1995

This study was investigated to find effects of soaking-water salt concentration and submaterial on Kimchi taste and fermentation period. several parameters such as pH, acidity, reducing sugar, amino acid and sensory evaluation during fermentation at 2$0^{\circ}C$ were experimented. The results are as follows : As fermentation period increases, pH and content of reducing sugar of Kimchi have decreased. But acidity has increased. Especially, the pH of all samples rapidly decreased to a extent of pH 4.2. During fermentation the acidity and content of reducing sugar in 12% soaking-water were higher than those in 16% and 20%. Content of reducing sugar I Kimchi was observed to play an important role for the overall taste. As a result of sensory evaluation during fermentation, Kimchi in 16%, 2.6% and in 20%, 3.7%. Sensory evaluation revealed that leek-added Kimchi was highly evaluated in crispness, sour taste, flavor and overall acceptability. These results suggested that Kimchi fermented for 4days at 2$0^{\circ}C$ with 16% salt concentration of soaking water and leek as submaterials should taste most desirable.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1163-1169
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• 2004

An unstructured mathematical model is presented for lactic acid fermentation based on the energy balance. The proposed model reflects the energy metabolic state and then predicts the cell growth, lactic acid production, and glucose consumption rates by relating the above rates with the energy metabolic rate. Fermentation experiments were conducted under various initial lactic acid concentrations of 0, 30, 50, 70, and 90 g/l. Also, a genetic algorithm was used for further optimization of the model parameters and included the operations of coding, initialization, hybridization, mutation, decoding, fitness calculation, selection, and reproduction exerted on individuals (or chromosomes) in a population. The simulation results showed a good fit between the model prediction and the experimental data. The genetic algorithm proved to be useful for model parameter optimization, suggesting wider applications in the field of biological engineering.

• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.70-74
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• 1991

The rheological properties of rifamycin B fermentation broth using Nocardia mediterranei were characterized in concomitance with the chemical changes of the fermentation broth. The data were interpreted with various rheological models. As results, it was found that the rheological behaviour at the early growth phases of the culture was the Newtonian fluid, but it was changed to the non-Newtonian fluid (Casson plastic behaviour) at the later phases of the culture. Rheological parameters viz., apparent viscosity ($\mu_a$), yield shear stress ($\tau_o$), and Casson constant ($K_c$) were changed through the fermentation where cell concentrations were changed and mycelia were greatly branched. Those results indicated that cell concentration and cell morphology played important roles to determine the rheological characters.

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.619-623
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• 1989

효모의 성장 및 에탄을 생산에 미치는 온도의 영향에 대해서 회분식 배양을 실시한 결과 최대의 비효모 성장속도를 나타내는 온도는 36$^{\circ}C$였고 최대의 비에탄을 생산속도를 나타내는 온도는 33$^{\circ}C$임을 알 수 있었다. 온도의 영향에 대한 실험을 토대로 수학적 모델식을 선정했으며 매개변수를 추정하여 모사를 해 본 결과 배양 초기에는 36$^{\circ}C$ 정도의 온도에서 배양하다가 점차로 온도를 낮추어 3$0^{\circ}C$ 정도로 배양하는 것이 최적의 발효공정임을 알 수 있었다.