• 제목/요약/키워드: secondary production

검색결과 852건 처리시간 0.022초

Biotechnological improvement of lignocellulosic feedstock for enhanced biofuel productivity and processing

  • Ko, Jae-Heung;Kim, Hyun-Tae;Han, Kyung-Hwan
    • Plant Biotechnology Reports
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    • 제5권1호
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    • pp.1-7
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    • 2011
  • Secondary walls have recently drawn research interest as a primary source of sugars for liquid biofuel production. Secondary walls are composed of a complex mixture of the structural polymers cellulose, hemicellulose, and lignin. A matrix of hemicellulose and lignin surrounds the cellulose component of the plant's cell wall in order to protect the cell from enzymatic attacks. Such resistance, along with the variability seen in the proportions of the major components of the mixture, presents process design and operating challenges to the bioconversion of lignocellulosic biomass to fuel. Expanding bioenergy production to the commercial scale will require a significant improvement in the growth of feedstock as well as in its quality. Plant biotechnology offers an efficient means to create "targeted" changes in the chemical and physical properties of the resulting biomass through pathway-specific manipulation of metabolisms. The successful use of the genetic engineering approach largely depends on the development of two enabling tools: (1) the discovery of regulatory genes involved in key pathways that determine the quantity and quality of the biomass, and (2) utility promoters that can drive the expression of the introduced genes in a highly controlled manner spatially and/or temporally. In this review, we summarize the current understanding of the transcriptional regulatory network that controls secondary wall biosynthesis and discuss experimental approaches to developing-xylem-specific utility promoters.

고급강 제조 반응 모델의 검토 : Part. 1. Coupled Reaction 기반 시뮬레이션 모델 (A Review of Kinetic Model for Production of Highgrade Steel : Part. 1. Simulation Model Based on Coupled Reaction)

  • 김정인;김선중
    • 자원리싸이클링
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    • 제30권1호
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    • pp.3-13
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    • 2021
  • 고급강은 소비자가 원하는 적절한 조성을 갖추고 있고 비금속 개재물의 제어를 통해 높은 청정도를 지닌 강을 의미하며, 철강 제품의 품질은 2차 정련 공정에서 제어하는 것이 지배적이다. 2차 정련에서는 시간이 흐름에 따라 용강, 슬래그, 비금속 개재물, 내화물 및 합금원소 간의 복잡한 반응이 동시에 일어나기 때문에 공정에 대한 제어가 쉽지 않다. 따라서 이전 연구자들은 2차 정련의 공정 예측을 위해 Kinetic 기반의 시뮬레이션 모델을 발표하였고, 정밀한 공정 예측을 위해 현재까지 발표된 시뮬레이션 모델들의 검토 및 분석이 필요하다. 본 연구에서는 Coupled Reaction 모델 기반의 2차 정련 모델들을 분석 및 검토하였고, 시뮬레이션 결과를 검토하였다.

The Distribution of Research Framework on Exsheetlink Module Development for Accounting Education

  • Nor Sa'adah, JAMALUDDIN;Rohaila, YUSOF;Noor Lela, AHMAD
    • 유통과학연구
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    • 제21권2호
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    • pp.45-52
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    • 2023
  • Purpose: The Malaysia Education Blueprint is primarily concerned with the transformation of students' minds through the curriculum offered at the school level (2013-2025). Diversity in the application of teaching and learning methods is one means of achieving the transformation of students' minds through the Secondary School Standard Curriculum. Consequently, the production of ExSheetLink's Module for Accounting Education is the primary outcome of this study, which had three objectives: the need for ExSheetLink's Module in the process of producing financial statements for Accounting Students in secondary school to the Accounting Teacher; and the design of ExSheetLink's Module that meets the entire process in the production of financial statements for Accounting Students in secondary school based on the Documents Curriculum and the Accounting Students' needs. Research design, data and methodology: This study outlines the research framework for module development in accordance with the Design and Development Research Method, which combines multiple research techniques (Mixed Method). Results: The development of ExSheetLink's Module is completed and can be used for the level of effectiveness purposes. Conclusion: The transformation of Accounting Students' minds is a success thanks to the ExSheetLink Module. Researchers also suggested that all Malaysian Secondary School accounting students test the ExSheetLink Module.

Streptomyces albulus 배양액으로부터 ε-poly-L-lysine의 분리 (Separation of ε-poly-L-lysine from the fermentation broth of Streptomyces albulus)

  • 선흥석;박찬영
    • 한국산업융합학회 논문집
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    • 제2권1호
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    • pp.77-83
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    • 1999
  • Grown in the secondary broth of production media, the strain Streptomyces albulus has increased more the production of its metabolite ${\varepsilon}$-poly-L-lysine, one of poly(amino acid)s used as disinfecting food additives, than the strain in the primary culture of growth nutrients. Having the strain removed, the large concentrate obtained by ultrafiltrating the secondary culture broth. The concentrated production broth exchanged into followed by detecting in UV flowcell at 220nm the peptide bond of the components eluting the adsorbed proteins and polylysine with NaCl salt of gradient concentration, and has separated into five components. Among them the component in the fourth peak fraction has proved to be the pure ${\varepsilon}$-poly-L-lysine after the portion being hydrolyzed the fraction with HCl into amino acid followed by being the composing amino acid analysis.

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2차 광학계가 필요없는 프레넬 렌즈를 이용한 중집광 광학계 시뮬레이션 (Fresnel lens optics simulation with middle sized linear concentration without secondary optics)

  • 강성원;김용식;심창호
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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    • pp.27-33
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    • 2011
  • HCPV(High Concentrated PV) systems have well known for CPV market all over the world. Low concentration type silicon based modules have been introduced in the market. But low cost of standard flat silicon modules made them useless nowadays. High cost of compound semiconductor solar cell reduced cost effective cpv module production than that of recently silicon solar cell. In order to overcome increasing cost of CPV module, we study middle concentration type fresnel lens simulation using concentrated type silicon based solar cell. Linear type fresnel lens made production of CPV module without secondary optics such as light pipe or light tunnel. This type of fresnel lens design makes more cost effective solution for cpv niche market.

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상호작용하의 층류 확산 화염에서 NO의 생성 (Production of NO in Interacting Laminar Diffusion Flames)

  • 전철균
    • 대한기계학회논문집
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    • 제17권1호
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    • pp.190-199
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    • 1993
  • 본 연구에서는 화염간 상호작용이 연소생성물 형성에 미치는 영향을 규명하기 위한 작업의 일환으로 대표적 연소 생성 공해 물질의 하나인 NO를 택하여 상호작용하 의 층류 확산화염에서 NO의 생성이 어떻게 이루어지는가를 검토 하고자 한다. 이를 위하여 기본적 다화염계인 2-화염계를 모사하는 수학적 모델을 수립하고 수치 계산을 통한 이론적 방법을 위주로하여 2개의 층류 확산 화염이 나타내는 상호작용 특성과 화 염간 상호작용이 NO형성에 미치는 영향을 규명하고자 한다.

Endophytic Fungi Inhabiting Medicinal Plants and Their Bioactive Secondary Metabolites

  • Lee, Changyeol;Shim, Sang Hee
    • Natural Product Sciences
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    • 제26권1호
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    • pp.10-27
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    • 2020
  • Endophytes are defined as microorganisms that spend part of lifetime interior of plant tissues without causing negative effects. They have been used for agricultural purpose, biofuel production, bioremediation, medication, etc. In particular, endophytes have been emerged as a good source for bioactive secondary metabolites. A large number of secondary metabolites are currently being reported. In this report, we focus on the secondary metabolites that were originated from endophytic fungi inhabiting medicinal plants. They were classified into several groups such as nitrogenous compounds, steroids, sulfide-containing metabolites, terpenoids, polyketides, and miscellaneous for discussion of chemical structures and biological activities.

Livestock Production under Coconut Plantations in Sri Lanka: 1. Social, Cultural and Economic Aspects of Buffalo Production

  • Jayatileka, T.N.;Weerakkody, P.R.;Ibrahim, M.N.M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권5호
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    • pp.586-596
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    • 1998
  • The relevance and importance of buffalo production under coconut plantations in the North Westen Province of Sri Lanka was studied in three districts (Bingiriya, Pannala, Kuliyapitiya). The objective of the study was to collect baseline information on socioeconomic and cultural aspects of buffalo production, with a view to promote and disseminate new technologies. The survey technique used consisted of a formal survey using a structured questionnaire (71 households) and rapid appraisal (55 households). The results indicate the existence of a wide stratification of dariy farmers which ranged from skilled dairy operators with high levels of production and management of efficiency to marginal subsistence farmers with low levels of productivity. The most frequent family size of households ranged from 4-5 members (58%), and the average family size was 4.7. The actual average land ownership accounts to 2.4 ha of upland and 0.5 ha of lowland, but when their accessibility to common property resources are taken into account, the land availability was assessed at 13 ha and 0.7 ha of upland and lowland, respectively. The highest average monthly income (Rs. 13,590) was received by farmers with off-farm employment (primary) who are also engaged in livestock production (secondary), and livestock contributed 43% of the total income. Livestock farmers who practised integrated crop farming as a secondary source of income received a monthly income of Rs. 10,843, and those involved in crop production as the primary source received the lowest average income (Rs. 7,295). The survey revealed a high investment cost on concentrate feeds (47%) for milk production. However some farmers obtained higher milk yields (11 litres/cow/day) at lower ration costs, and this could be attributed to the entrepreneurship skills and management efficiency. The study area had a well developed market infrastructure for fresh milk, principally due to the existence of the Nestle's company and the Coconut Triangle Milk Union. On an average the producer collected Rs. 10 per litre of milk marketed.

Synthetic Biology Tools for Novel Secondary Metabolite Discovery in Streptomyces

  • Lee, Namil;Hwang, Soonkyu;Lee, Yongjae;Cho, Suhyung;Palsson, Bernhard;Cho, Byung-Kwan
    • Journal of Microbiology and Biotechnology
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    • 제29권5호
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    • pp.667-686
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    • 2019
  • Streptomyces are attractive microbial cell factories that have industrial capability to produce a wide array of bioactive secondary metabolites. However, the genetic potential of the Streptomyces species has not been fully utilized because most of their secondary metabolite biosynthetic gene clusters (SM-BGCs) are silent under laboratory culture conditions. In an effort to activate SM-BGCs encoded in Streptomyces genomes, synthetic biology has emerged as a robust strategy to understand, design, and engineer the biosynthetic capability of Streptomyces secondary metabolites. In this regard, diverse synthetic biology tools have been developed for Streptomyces species with technical advances in DNA synthesis, sequencing, and editing. Here, we review recent progress in the development of synthetic biology tools for the production of novel secondary metabolites in Streptomyces, including genomic elements and genome engineering tools for Streptomyces, the heterologous gene expression strategy of designed biosynthetic gene clusters in the Streptomyces chassis strain, and future directions to expand diversity of novel secondary metabolites.