• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1136-1144
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• 2016

Leucaena silage was supplemented with different levels of molasses and urea to study its nutritive value and in vitro rumen fermentation efficiency. The ensiling study was randomly assigned according to a $3{\times}3$ factorial arrangement in which the first factor was molasses (M) supplement at 0%, 1%, and 2% of crop dry matter (DM) and the second was urea (U) supplement as 0%, 0.5%, and 1% of the crop DM, respectively. After 28 days of ensiling, the silage samples were collected and analyzed for chemical composition. All the nine Leucaena silages were kept for study of rumen fermentation efficiency using in vitro gas production techniques. The present result shows that supplementation of U or M did not affect DM, organic matter, neutral detergent fiber, and acid detergent fiber content in the silage. However, increasing level of U supplementation increased crude protein content while M level did not show any effect. Moreover, the combination of U and M supplement decreased the content of mimosine concentration especially with M2U1 (molasses 2% and urea 1%) silage. The result of the in vitro study shows that gas production kinetics, cumulation gas at 96 h and in vitro true digestibility increased with the increasing level of U and M supplementation especially in the combination treatments. Supplementation of M and U resulted in increasing propionic acid and total volatile fatty acid whereas, acetic acid, butyric acid concentrations and methane production were not changed. In addition, increasing U level supplementation increased $NH_3$-N concentration. Result from real-time polymerase chain reaction revealed a significant effect on total bacteria, whereas F. succinogenes and R. flavefaciens population while R. albus was not affected by the M and U supplementation. Based on this study, it could be concluded that M and urea U supplementation could improve the nutritive value of Leucaena silage and enhance in vitro rumen fermentation efficiency. This study also suggested that the combination use of M and U supplementation level was at 2% and 1%, respectively.

• 한국토양비료학회지
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• 제34권4호
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• pp.284-291
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• 2001

유기질비료와 화학비료 시용에 따른 작물체의 질소동위원소비 (${\delta}^{15}N$) 차이 유무를 조사하기 위해 포트 조건에서 돈분 퇴비 (+13.9‰) 와 요소(-2.3‰) 를 시용하여 70일간 재배한 옥수수의 뿌리, 줄기, 잎, 알곡에 대한 ${\delta}^{15}N$ 값을 분석하였고, 동위원소 질량수지 방정식을 이용하여 옥수수 전부위에 대한 ${\delta}^{15}N$ 값을 계산하였다. 옥수수의 ${\delta}^{15}N$값은 토양 질소의 영향과 질소의 형태변환과정에 수반되는 동위원소분할효과에 의해 시용한 퇴비와 요소의 ${\delta}^{15}N$ 값과 차이를 보였다. 옥수수 전부위, 뿌리 및 줄기의 ${\delta}^{15}N$ 값은 요소와 퇴비 시용에 따른 유의성 있는 차이 (p<0.05)를 나타내지 않았지만, 잎과 알곡의 ${\delta}^{15}N$ 값은 각각 퇴비 처리구(+14.3‰, +16.2‰) > 무처리구(+13.2‰, +13.9‰) > 요소-퇴비 혼합처리구(+10.1‰, +12.6‰) 요소 처리구 (+10.1‰, +12.4‰)의 순서로 유의성 있는 차이가 나타났다. 따라서, 본 연구는 시용 질소원의 종류(퇴비 또는 화학비료)를 확인하는데 있어서 작물의 잎 또는 알곡의 ${\delta}^{15}N$ 값 활용 가능성을 제시해주는 것으로 판단되었다. 하지만, 보다 일반적인 결론을 얻기 위해서는 다양한 종류의 토양과 작물에 대한 연구가 요구된다.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1280-1290
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• 2014

In order to obtain the cellulolytic bacterial consortia, sediments from Great Basin hot springs (Nevada, USA) were sampled and enriched with cellulosic biomass as the sole carbon source. The bacterial composition of the resulting anaerobic ethanol-producing celluloytic bacterial consortium, named SV79, was analyzed. With methods of the full-length 16S rRNA library-based analysis and denaturing gradient gel electrophoresis, 21 bacteria belonging to eight genera were detected from this consortium. Clones with closest relation to the genera Acetivibrio, Clostridium, Cellulosilyticum, Ruminococcus, and Sporomusa were predominant. The cellulase activities and ethanol productions of consortium SV79 using different agricultural residues (sugarcane bagasse and spent mushroom substrate) and energy crops (Spartina anglica, Miscanthus floridulus, and Pennisetum sinese Roxb) were studied. During cultivation, consortium SV79 produced the maximum filter paper activity (FPase, 9.41 U/ml), carboxymethylcellulase activity (CMCase, 6.35 U/ml), and xylanase activity (4.28 U/ml) with sugarcane bagasse, spent mushroom substrate, and S. anglica, respectively. The ethanol production using M. floridulus as substrate was up to 2.63 mM ethanol/g using gas chromatography analysis. It has high potential to be a new candidate for producing ethanol with cellulosic biomass under anoxic conditions in natural environments.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.358-360
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• 1999

The effect of pectinase on menthol production by Mentha piperita in shake flasks was investigated. The optimum concentration of pectinase and period of elicitation for menthol production were 15 U/1 and 9 days, respectively. Pectinase elicitation at 15 U/1 for 9 days using a Lin-Staba medium with 2,4-dichlorophenoxyacetic acid (2,4-D) enhanced menthol production 37-fold (211.5 ㎎ menthol/l) with the specific menthol concentration (menthol concentration per unit weight of cells) of 27.5 ㎎/g dry cell weight (DCW). Our results also indicate that pectinase elicitation may activate the conversion of pulegone to menthol.

• Mycobiology
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• 제50권4호
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• pp.189-202
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• 2022

An investigation of species of the genus Aspergillus present in arthropod, freshwater, and soil led to the discovery of seven undescribed species in Korea. Based on their morphological characteristics and molecular phylogeny analyses using a combined data set of β-tubulin (BenA) and calmodulin (CaM) sequences, the isolated strains CNUFC IGS2-5, CNUFC YJ1-19, CNUFC WD27, CNUFC U8-70, CNUFC AS2-24, CNUFC S32-1, and CNUFC U7-48, were identified as Aspergillus brunneoviolaceus, A. capensis, A. floccosus, A. inflatus, A. parvulus, A. polyporicola, and A. spelaeus, respectively. In the present study, the detailed morphological descriptions and phylogenetic relationships of these species are provided.

• 한국유기농업학회지
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• 제10권3호
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• pp.25-39
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• 2002

This paper aims to provide quite recent information on the organic industry in the U.S. Major focuses are on the development of cultivation and marketing of fresh and processed organic produce and foods, newly enforced certification program, consumers' purchasing behaviors toward organic foods, and social survey results administered to the organic farmers in the U.S. The U.S. recorded 8 billion dollars' sale of organic foods in 2000, which was the largest in the world and showed 23% growth compared to the previous year. Yet the organic industry is still a niche market, occupying merely 1.5% of total food sale amount. The natural foods markets have not been so concentrated in the U.S., but it is changing and a few wholesale mart such as Whole Foods is emerging. Recent introduction of new certification program provide unified and sole standard at the federal level to which every certifier needs to adjust itself in order to be acceredited by the government. According to a social survey, consumers purchase organic foods because they concern about health, they stick to their own modes of life favoring natural foods, and so on. Another social survey shows that most organic farmers sell their produces to wholesalers, distributers, or producer coop, and direct sale to visitors at their own farm comprises of about 8 percent of their organic land.

• Biodesign
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• 제6권4호
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• pp.96-99
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• 2018

The gram-positive bacterium Staphylococcus aureus is a common cause of abscesses, sinusitis and food poisoning. The emergence of antibiotic-resistant strains has caused significant clinical issues worldwide. The HslU-HslV complex was first identified as a prokaryotic homolog of eukaryotic proteasomes. HslU is an unfoldase that mediates the unfolding of the substrate proteins, and it works with the protease HslV in the complex. To date, the protein complex has been mostly studied in gram-negative bacteria. In this study, we report the purification and crystallization of the full-length HslU from S. aureus. The crystal diffracted X-rays to a $3.5{\AA}$ resolution, revealing that the crystals belong to space group $P2_1$, with unit cell parameters of a = 166.5, b = 189.6, $c=226.6{\AA}$, and ${\beta}=108.1^{\circ}$. We solved the phage problem by molecular replacement using the structure of HslU from Haemophilus influenzae as a search model. The cell content analysis with this molecular replacement solution revealed that 24 molecules are contained in the asymmetric unit. This structure provides insight into the structural and mechanistic difference of the HslUV complex of gram-positive bacteria.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.837-844
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• 2006

Four, lactating dairy cows were randomly assigned according to a $2{\times}2$ Factorial arrangement in a $4{\times}4$ Latin square design to study supplementation of urea level (U) at 2 and 4% and sodium dl-malate (M) at 10 and 20 g/hd/d in concentrate. The treatments were as follows U2M10, U2M20, U4M10 and U4M20, respectively. The cows were offered the treatment concentrate at a ratio to milk yield at 1:2.5 and urea-treated rice straw was fed ad libitum. The results have revealed that rumen fermentation and blood metabolites were similar for all treatments. The populations of protozoa and fungal zoospores were significantly different as affected by urea level and sodium dl-malate. In addition, the viable bacteria were similar for amylolytic and proteolytic bacteria. Cellulolytic bacteria were significantly affected by level of sodium dl-malate especially Selenomonas ruminantium and Megasphaera elsdenii while Butyrivibrio fibrisolvens was significantly affected by level of urea supplementation. In conclusion, the combined use of concentrate containing high level of cassava chip at 75% DM with urea at 4% in concentrate and sodium dl-malate at 20 g/hd/d with UTS as a roughage could improv rumen ecology and microbial protein synthesis efficiency in lactating dairy cows.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.303-311
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• 2020

미국의 탄저린 감귤귤 재배면적은 2009년 19,000ha에서 2016년 27,000ha로 급격히 증가하여 7년 동안 42% 증가했다. 최근 일본으로의 수출이 급증함에 따라 향후 약 6 ~7천 톤의 수출량이 증가할 가능성이 높다. 따라서, 본연구의 목적은 미국 탄저린 수입이 감귤산업에 미치는 경제적 파급효과를 다양한 시나리오를 통해 시뮬레이션 분석을 하는데 있다. 미국 탄저린감귤의 수입 가능성을 조사하기 위해 미국 감귤이 수입된 적인 없기 때문에 미국 탄저린 감귤의 일본 수출 단가가 사용되었다. 감귤류는 재배 방법과 품종에 따라 노지감귤, 하우스감귤, 한라봉 등 만감류(월동 온주 포함)로 분류하였다. 노지와 하우스감귤의 생산시즌을 고려해 보면, 미국 탄저리감귤의 수입량은 2021년 약 4,700 톤에서 2027년에는 10,000톤으로 증가할 것으로 예상된다. 미국 탄저린감귤의 수입은 국내산 노지와 하우스감귤의 생산량과 품질뿐만 아니라 미국산 탄저린감귤의 생산량에 따라 변동될 수 있다. 그렇지만, 미국 탄저린감귤의 관세율이 50% 이하로 떨어지는 2021년 이후에는 수입될 수 있다는 점을 명심해야 한다.

• 한국식품영양과학회지
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• 제38권1호
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• pp.76-82
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• 2009

본 연구에서는 발효과정 중 누룩의 일반성분 및 효소 활성변화를 측정하고, 단백질의 분해정도와 밀 단백질에 민감한 환자의 혈청과 반응성을 관찰하였다. 누룩의 수분함량은 발효 1일 24.20%였으며 발효가 진행됨에 따라 미생물의 이용과 증발로 인해 감소되어 발효 15일에는 13.60%를 나타내었다. 누룩 발효 중 총당과 환원당의 함량은 발효시간이 경과함에 따라 증가하는 경향을 나타내었다. 누룩의 발효 초기 조단백질 함량은 1.58%였으나 발효가 진행됨에 따라 다소증가하여 발효 15일에는 2.05%로 나타났다. 또한 누룩의 조지방 함량은 발효 초기 1.32%였으며 발효 15일에는 2.24%로 다소 증가함을 나타내었다. ${\alpha}$-Amylase 활성은 발효 초기 1,416.67 U/g에서 발효 15일에는 2,833.00 U/g으로 급격히 증가하였으며, glucoamylase 활성은 발효 초기 497.90 U/g에서 발효 10일 경과 후 705.40 U/g으로 최대 활성을 보였으나 그 후 완만한 감소를 나타내었다. 누룩의 산성 protease 활성은 발효 초기에는 검출되지 않았으나 발효 10일에 75.00 U/g으로 급격히 증가하기 시작하여 발효 15일에는 327.00 U/g에 도달하였으며 중성 protease 활성도 발효 10일에 90.00 U/g으로 급격히 증가하기 시작하여 15일에는 354.00 U/g로 검출되었으며 이후에도 계속 증가하였다. 반면에 알칼리성 protease 활성은 검출되지 않았다. 발효가 진행됨에 따라 누룩 중 고분자 단백질이 각종 미생물에 의해 분해되어 저분자의 펩타이드 밴드가 생성되었으며 밀 민감성 환자의 혈청과 반응하는 밴드도 점차 감소하여 발효 15일에는 거의 검출되지 않았으므로 누룩 중 밀 단백질의 항원성이 감소하였음을 확인할 수 있었다. 따라서 본 연구를 통해 누룩은 영양학적 측면뿐만 아니라 효소학적 측면의 장점까지 겸비한 효율적인 한국 고유의 발효 식품용 스타터(starter)로써 전통주 제조에 필수적이며, 누룩의 고분자 단백질이 발효에 의해 저분자 펩타이드로 분해됨을 확인함으로써 밀 민감성 환자들을 위한 다양한 가공식품용 소재로 활용이 기대된다.