• 제목/요약/키워드: Digesting

검색결과 104건 처리시간 0.02초

Effect of seaweed addition on enhanced anaerobic digestion of food waste and sewage sludge

  • Shin, Sang-Ryong;Lee, Mo-Kwon;Im, Seongwon;Kim, Dong-Hoon
    • Environmental Engineering Research
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    • 제24권3호
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    • pp.449-455
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    • 2019
  • To investigate the effect of seaweed (SW) addition on anaerobic co-digestion of food waste (FW) and sewage sludge (SS), batch experiments were conducted at various substrate concentrations (2.5, 5.0, 7.5, and 10.0 g volatile solids (VS)/L) and mixing ratios ((FW or SS):SW = 100:0, 75:25, 50:50, 25:75, and 0:100 on a VS basis). The effect of SW addition on FW digestion was negligible at low substrate concentration, while it was substantial at high substrate concentrations by balancing the rate of acidogenesis and methanogenesis. At 10 g VS/L, $CH_4$ production yield was increased from 103 to $350mL\;CH_4/g$ VS by SW addition (FW:SW = 75:25). On the other hand, SW addition to SS enhanced the digestion performance at all substrate concentrations, by providing easily biodegradable organics, which promoted the hydrolysis of SS. $k_{hyd}$ (hydrolysis constant) value was increased from 0.19 to $0.28d^{-1}$ by SW addition. The calculation showed that the synergistic $CH_4$ production increment by co-digesting with SW accounted for up to 24% and 20% of total amount of $CH_4$ production in digesting FW and SS, respectively.

Delphi기법에 의한 기계공학기술과 다른 기술분야의 국제적 기술수준과 국제기술협력 가능성에 대한 비교연구 (A Comparative Study on the International Technology Levels and R&D Cooperation Capabilities of Mechanical Engineering and Other Technologies by Delphi Method)

  • 권영주
    • 한국정밀공학회지
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    • 제14권6호
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    • pp.74-82
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    • 1997
  • We provide a set of information on technologies to draw meaningful action plans for the internationalization on National R&D activities. In this study, we employed a modiffed Delphi method to evaluate levels of our technological capabilities and developed countries as well. We investigated technology acquis- tion methodologies, technology characteristics and various aspects of international cooperation in terms of technology. Then, we analyzed final responses of participants (i.e., the third round results of Delphe method) to see the correlation among various factors in developing technologies through international R&D cooperation. The technology classification used in this research was developed by STEPI (Science and Technology Policy Institute). In conclusion, levels of our technologies were investigated to be between the stage of imi- tating/absorbing advanced thechnologies and the stage of digesting acquired technologies. Especially, com- paring with other technologies, mechanical engineering was evaluated to be almost near the stage of digesting acquired technology(the middle level stage of technology). Our overal technological capabilities were evaluated to be 40 .approx. 60% of top level countries.

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쇠비름(Portulaca oleracea L.) 추출물의 탄수화물 소화 효소 저해와 식후 고혈당 완화 효과 (Portulaca oleracea L. Extract Lowers Postprandial Hyperglycemia by Inhibiting Carbohydrate-digesting Enzymes)

  • 박재은;한지숙
    • 생명과학회지
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    • 제28권4호
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    • pp.421-428
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    • 2018
  • 식후고혈당은 제 2형 당뇨병의 발병에 부정적인 영향을 미치고 미세혈관 및 대혈관 질환 등의 당뇨병 합병증 유발과 밀접한 관계가 있다. 따라서 식후고혈당을 조절하는 것이 당뇨병 합병증의 위험을 줄이는 가장 중요한 요소이다. 식후고혈당은 소장에서 ${\alpha}$-글루코시다아제와 같은 탄수화물 소화 효소를 저해함으로써 조절될 수 있다. 이에 본 연구는 쇠비름 에탄올 추출물(PEE)과 물 추출물(PWE)이 탄수화물 소화 효소를 저해하고, 당뇨병 마우스에서 식후 고혈당을 강하시키는 효과에 대해 조사하였다. ${\alpha}$-글루코시다아제와 ${\alpha}$-아밀라아제에 대한 저해효과는 두 추출물 모두 양성대조군인 acarbose보다 더 효과적이었으며, PEE에 의한 ${\alpha}$-글루코시다아제 저해 효과가 PWE 보다 더 효과적이었다. Diabetic mice에 전분(2 g/kg)을 투여한 후의 혈당 증가는 30, 60, 120분에 각각 383.7, 429.3, 360.2 mg/dL로 나타났고, 전분(2 g/kg)과 PEE 또는 PWE 추출물(300 mg/Kg)을 투여한 후의 혈당 증가는 30, 60, 120분에 각각 337.0, 368.5, 290.1 mg/dL과 365.8, 379.2, 324.3 mg/dL로 나타나, PEE 추출물 투여군이 대조군에 비해 식후 혈당 강하가 효과적으로 나타남을 알 수 있었다. 이러한 결과는 쇠비름 추출물이 탄수화물 소화효소를 저해함으로써 식후 고혈당을 완화시키고, 특히 쇠비름 에탄올 추출물(PEE)이 쇠비름 물 추출물(PWE) 보다 식후 고혈당을 완화시키는데 더욱 효과가 있는 것으로 나타났다.

순천시의 폐사가축 처리실태에 관한 연구 (Farm Animal Mortality Management Practices in Sunchon-si)

  • 홍지형
    • 한국축산시설환경학회지
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    • 제16권3호
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    • pp.245-252
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    • 2010
  • 축산업의 대규모 전업화로서 폐사가축이 급증되어서 대기, 수질, 토양, 지하수 등의 환경오염 및 쥐. 파리. 까마귀 등의 썩은 고기를 좋아하는 위해동물 번식으로 인하여 자연환경이 오염되어가고 있다. 전라남도 순천 지역 중심의 축종별 호당 연간평균 사육두수는 양계농가 251,000마리, 양돈농가 2,600두, 한우농가 142두 및 낙농가 92두 등 이었으며, 호당 연간추정 폐사가축 발생량은 양계농가 0.46톤, 양돈농가 15.32톤, 한우농가 0.36톤 및 낙농가 1.33톤 등이었다. 순천지역 축산농가의 연간 추정 폐사가축 발생량은 2,754톤 이였으며, 특히 양돈농가 폐사가축 발생량은 1,287톤으로 전체발생량의 47%를 차지하였다. 폐사가축 처리방식은 산지와 과수원 등에 매몰처리 (42%)와 축분에 투기처리 (36%)가 대부분 (78%)이며, 개별농가 사정에 따라서 렌더링, 간이소각, 침지소화 및 사체처리기 등이 활용되었다. 폐사가축처리시설 선정은 매몰처리로 발생하는 수질 및 대기오염, 위해동물 발생, 질병확산 위험 등이 없고, 처리비용이 다른 방법보다 저렴한 폐사가축 퇴비화시설 도입이 필요하였다.

병원입원 환자에게 실시되는 한국음식의 조리법 표준화를 위한 연구 (A Study on the standardization of Cooking Method of Korean Food for Hospital Patients)

  • 정해옥
    • 한국조리학회지
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    • 제6권3호
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    • pp.149-166
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    • 2000
  • In this study, author suggests menu selection according to disease and standard cooking methods for hospital patients. Nutritional state of patients must be considered to select menu. Especially age, sex, and disease symptoms are important factors to determine the nutritional requirement. Special diet should be delivered to cure the patients with different appetite, digesting ability and symptoms. Menu must be planed including various food although nutritional restrictions should be considered, In this point of view, effective cooking methods and considerations of various Korean traditional food as hospital food are suggested. Recipe of traditional Korean beverage and cookies are also presented.

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Extension of a 5'- or 3'-end Genomic DNA Sequence by a Single PCR Amplification

  • Jeon, Taeck J.
    • 통합자연과학논문집
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    • 제1권3호
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    • pp.230-233
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    • 2008
  • A simple and rapid method is described for extending the 5'- or 3'-end genomic sequence of a known partial sequence by only a single round of PCR. This method involves digesting and ligating genomic and plasmid DNAs, and amplifying the 5'-upstream or 3'-end downstream sequence of the known DNA sequence, using two primers, one gene specific and the other plasmid specific. A single round of PCR amplification is sufficient to produce gene-specific bands detectable in gels. By using this approach, 5'-end genomic sequence of the D-amoeba sams gene was extended.

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The impact of diet on the composition and relative abundance of rumen microbes in goat

  • Liu, Kaizhen;Xu, Qin;Wang, Lizhi;Wang, Jiwen;Guo, Wei;Zhou, Meili
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권4호
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    • pp.531-537
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    • 2017
  • Objective: This experiment was conducted to explore the impact of diet on the ruminal microbial community in goats. Methods: Twelve goats were divided into two groups and fed complete feed (CF) or all forage (AF) diet. The total microbial DNAs in the rumen liquid were extracted. The V4 region of microbial 16S rRNA genes was amplified and sequenced using high-throughput. Information of sequences was mainly analyzed by QIIME 1.8.0. Results: The results showed that Bacteroidetes and Firmicutes were the most predominant microbial phyla in the rumen of all goats. At genus level, the abundance of fiber-digesting bacteria such as Ruminococcus and Lachnospiracea incertae sedis was significantly higher in AF than that in CF, while the levels of fat-degrading bacterium Anaerovibrio and protein-degrading bacterium Pseudomonas were opposite. The core shared genera, Prevotella and Butyrivibrio were widespread in the rumen of goats and no significant difference was observed in relative abundance between groups. Conclusion: We concluded that the richness of fiber-, protein-, and fat-digesting bacteria was affected by diet and tended to increase with the rise of their corresponding substrate contents in the ration; some bacteria shared by all goats maintained stable despite the difference in the ration, and they might be essential in maintaining the normal function of rumen.

강력한 생전분 분해효소의 개발과 특성 (Studies on the Development and the Characteristics of the Powerful Raw Starch Digesting Enzyme)

  • 정만재;허원녕;;정재현
    • 한국미생물·생명공학회지
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    • 제18권3호
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    • pp.251-259
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    • 1990
  • 생전분 분해력이 강력한 glucoamylase를 생산하는 균주로서 Asp.usamii IAM 2185를 선정하였다. 밀기울배지에서의 효소생산의 최적 initial pH는 6.0-8.0, 최적 배양온도는 25-$30^{\circ}C$, 최적 배양시간은 72시간이고, 밀기울배지에 ammonuim nitrate와 albumin의 첨가는 효소의 생산을 약간 증가시켰다. 황산암모늄분획, CM-cellulose와 DEAE-cellulose column chromatography에 의하여 효소를 정제하였고, 정제효소의 specific activity는 34.3U/mg.protein, 수율은 10.3 이었다.

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Microbial Community Diversity in Anaerobic Reactors Digesting Turkey, Chicken, and Swine Wastes

  • Ziganshina, Elvira E.;Belostotskiy, Dmitry E.;Shushlyaev, Roman V.;Miluykov, Vasili A.;Vankov, Petr Y.;Ziganshin, Ayrat M.
    • Journal of Microbiology and Biotechnology
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    • 제24권11호
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    • pp.1464-1472
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    • 2014
  • The microbial community structures of two continuous stirred tank reactors digesting turkey manure with pine wood shavings as well as chicken and swine manure were investigated. The reactor fed with chicken/swine wastes displayed the highest organic acids concentration (up to 15.2 g/l) and ammonia concentration (up to 3.7 g/l ammonium nitrogen) and generated a higher biogas yield (up to $366ml/g_{VS}$) compared with the reactor supplied with turkey wastes (1.5-1.8 g/l of organic acids and 1.6-1.7 g/l of ammonium levels; biogas yield was up to $195ml/g_{VS}$). The microbial community diversity was assessed using both sequencing and profiling terminal restriction fragment length polymorphisms of 16S rRNA genes. Additionally, methanogens were analyzed using methyl coenzyme M reductase alpha subunit (mcrA) genes. The bacterial community was dominated by members of unclassified Clostridiales with the prevalence of specific clostridial phylotypes in each reactor, indicating the effect of the substrate type on the community structure. Of the methanogenic archaea, methanogens of the genus Methanosarcina were found in high proportions in both reactors with specific methanosarcinas in each reactor, whereas the strict hydrogenotrophic methanogens of Methanoculleus sp. were found at significant levels only in the reactor fed with chicken/swine manure (based on the analyses of 16S rRNA gene). This suggests that among methanogenic archaea, Methanosarcina species which have different metabolic capabilities, including aceticlastic and hydrogenotrophic methanogenesis, were mainly involved in anaerobic digestion of turkey wastes.

Molecular Cloning and Determination of the Nucleotide Sequence of Raw Starch Digesting α-Amylase from Aspergillus awamori KT-11

  • Matsubara, Takayoshi;Ammar, Youssef Ben;Anindyawati, Trisanti;Yamamoto, Satoru;Ito, Kazuo;Iizuka, Masaru;Minamiura, Noshi
    • BMB Reports
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    • 제37권4호
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    • pp.429-438
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    • 2004
  • Complementary DNAs encoding $\alpha$-amylases (Amyl I, Amyl III) and glucoamylase (GA I) were cloned from Aspergillus awamori KT-11 and their nucleotide sequences were determined. The sequence of Amyl III that was a raw starch digesting $\alpha$-amylase was found to consist of a 1,902 bp open reading frame encoding 634 amino acids. The signal peptide of the enzyme was composed of 21 amino acids. On the other hand, the sequence of Amyl I, which cannot act on raw starch, consisted of a 1,500 bp ORF encoding 499 amino acids. The signal peptide of the enzyme was composed of 21 amino acids. The sequence of GA I consisted of a 1,920 bp ORF that encoded 639 amino acids. The signal peptide was composed of 24 amino acids. The amino acid sequence of Amyl III from the N-terminus to the amino acid number 499 showed 63.3% homology with Amyl I. However, the amino acid sequence from the amino acid number 501 to C-terminus, including the raw-starch-affinity site and the TS region rich in threonine and serine, showed 66.9% homology with GA I.