• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.374-378
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• 2011

To find alternative genetic resources for D-serine dehydratase (E.C. 4.3.1.18, dsdA) mediating the deamination of D-serine into pyruvate, metagenomic libraries were screened. The chromosomal dsdA gene of a wild-type Escherichia coli W3110 strain was disrupted by inserting the tetracycline resistance gene (tet), using double-crossover, for use as a screening host. The W3110 dsdA::tet strain was not able to grow in a medium containing D-serine as a sole carbon source, whereas wild-type W3110 and the complement W3110 dsdA::tet strain containing a dsdA-expression plasmid were able to grow. After introducing metagenome libraries into the screening host, a strain containing a 40-kb DNA fragment obtained from the metagenomic souce derived from a compost was selected based on its capability to grow on the agar plate containing D-serine as a sole carbon source. For identification of the genetic resource responsible for the D-serine degrading capability, transposon-${\mu}$ was randomly inserted into the 40-kb metagenome. Two strains that had lost their D-serine degrading ability were negatively selected, and the two 6-kb contigs responsible for the D-serine degrading capability were sequenced and deposited (GenBank code: HQ829474.1 and HQ829475.1). Therefore, new alternative genetic resources for D-serine dehydratase was found from the metagenomic resource, and the corresponding ORFs are discussed.

• 한국콘텐츠학회논문지
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• 제15권9호
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• pp.639-651
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• 2015

본 연구는 지식기반과 메타기억이 범주 예 생성 과제를 통해 측정되는 개념적 암묵적 기억에 영향을 미치는 지를 살펴보는데 목적이 있다. 본 연구의 대상은 서울과 경기도의 초등학교 2학년 60명, 초등학생 6학년 60명, 고등학생 60명, 총 180명이었다. 대상 아동들에게 범주예 생성 암묵적 기억검사, 지식기반검사, 메타기억검사를 시행하였다. 수집된 자료는 공변량 분석을 실시하였고, Scheffe 사후검증을 실시하였다. 연구결과 첫째, 연령이 높을수록 암묵적 기억이 발달하였다. 암묵적 기억량은 초등학교 2학년과 고등학생, 초등학교 6학년과 고등학생 간에 유의하게 차이가 나타났다. 둘째, 아동의 지식기반수준이 높을수록 암묵적 기억이 발달하였다. 연령과 지식기반의 유의한 차이가 나타났다. 셋째, 아동의 메타기억이 높을수록 암묵적 기억이 발달하였다. 본 연구결과들로 연령, 지식기반, 그리고 메타기억이 암묵적 기억의 발달에 중요한 요인이라는 것을 알 수 있었다. 그리고 아동이 연령에 따라 지식기반과 메타기억이 발달한다면 암묵적 기억이 발달할 것이라는 시사점을 제공한다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.489-492
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• 2000

The eventual goal of this study is to elucidate roles of plant terpenoids (e.g., cymene, limonene and others) as natural substrates in the cometabolic biodegradation of PCBs and to develop an effective PCB bioremediation technology. The aim of this study was to examine how plant terpenoids, as natural substrates or inducers would affect the biodegradation of PCB congeners. Various PCB degraders that could grow on biphenyl and several terpenoids were tested for their PCB degradation capabilities. The PCB congener degradation activities were first monitored through resting cell assay technique that could detect degradation products of the substrate. The congener removal was also confirmed by concommitant GC analysis. The PCB degraders, Pseudononas sp. P166 and Caynebacterium sp. T104 were found to grow on both biphenyl and terpenoids ((S)-(-) limonene, p-cymene and ${\alpha}-terpinene$) whereas Arthrobacter B1B could not grow on the terpenoids as a sole carbon source. The strain B1B grown on biphenyl showed a good degradation activity for 4,4'-dichlorobiphenyl (DCBp) while strains P166 and T104 gave about 25% of B1B activity. Induction of degradation by cymene, limonene and terpine was hardly detected by the resting cell assay technique. This appeared to be due to relatively lower induction effect of these terpenoids compared with biphenyl. However, a subsequent GC analysis showed that the congener could be removed up to 30% by the resting cells of T104 grown on the terpenoids. This indicates that terpenoids, widely distributed in nature, could be utilized as both growth and/or inducer substrate for PCB biodegradation.

• 생명과학회지
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• 제13권6호
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• pp.933-942
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• 2003

Coenzyme Q은 긴 isoprenoid 사슬을 갖는 quinone의 유도체이다. Coenzyme Q는 진핵생명체의 미토콘드리아의 내막과 원핵생명체의 세포막에 위치하는 전자전달계에 존재하는 지용성 물질이며, 또한 항산화제로의 기능도 갖는다. Coenzyme Q는 Saccharomyces cerevisiae의 호기적 성장에 필수적이며, coq 돌연변이체는 발효가 불가능한 탄소 원에서의 성장이 불가능하다. S. cerevisiae의 $coq^7$p 효소들과 유사성을 나타내는 단백질을 암호화하는 Neurcspora crassa cDNA를 효모의 발현 벡터에 삽입하였다. N. crassa COQ7의 예상 서열은 S. cerevisiae의 효소와 58% homology를 보였다. N. crassa $coq^{-7}$ 유전자의 S. cerevisiae $coq^7$ 형질전환체는 야생형 균주와 유사한 성장률을 보였다. 형질전환 균주들은 발효가 불가능한 탄소원인 글리세롤을 유일한 탄소원으로 배양하였을 경우에도 정상적인 성장을 나타냈다. 또한 불포화지방산인 linolenic acid를 성장 배지에 첨가하여도 야생형 균주와 유사한 생존율이 관찰되었다.

• Journal of Microbiology
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• 제43권4호
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• pp.325-330
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• 2005

Rhodococcus sp. strain YU6 was isolated from soil for the ability to grow on o-xylene as the sole carbon and energy source. Unlike most other o-xylene-degrading bacteria, YU6 is able to grow on p-xylene. Numerous growth substrate range experiments, in addition to the ring-cleavage enzyme assay data, suggest that YU6 initially metabolizes 0- and p-xylene by direct aromatic ring oxidation. This leads to the formation of dimethylcatechols, which was further degraded largely through meta-cleavage path-way. The gene encoding meta-cleavage dioxygenase enzyme was PCR cloned from genomic YU6 DNA using previously known gene sequence data from the o-xylene-degrading Rhodococcus sp. strain DK17. Subsequent sequencing of the 918-bp PCR product revealed a $98\%$ identity to the gene, encoding meth-ylcatechol 2,3-dioxygenase from DK17. PFGE analysis followed by Southern hybridization with the catechol 2,3-dioxygenase gene demonstrated that the gene is located on an approximately 560-kb megaplasmid, designated pJY J1

• 한국산학기술학회논문지
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• 제15권5호
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• pp.2678-2688
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• 2014

본 연구의 목적은 아버지의 자녀가치, 양육신념, 양육참여가 영아의 발달특성에 어떠한 영향을 미치는지 살펴보고 변인들의 설명력을 알아보는데 있다. 연구대상은 2010년도에 출생한 영아 1,802명과 그의 아버지이며 이를 대상으로 한 육아 정책연구소 한국아동패널 3차년도 데이터를 사용하였다. 자료의 분석은 SPSS 18.0을 이용하여 상관분석, 다중회귀분석을 실시하였으며 연구결과는 다음과 같다. 아버지의 자녀가치는 영아의 문제해결능력, 소근육 활동에 영향을 미치고 영아의 대근육 활동에는 아버지의 변인들이 영향을 미치지 않았으며 영아의 의사소통, 개인-사회성에 영향을 미치는 독립변인은 아버지 양육참여로 나타났다.

• 한국산림과학회지
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• 제7권1호
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• pp.40-44
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• 1968

1. 가해기(加害期) 충영내(虫癭內) 솔잎혹파리유충(幼虫)은 7월초순(月初旬)부터 서서히 자라며 9월(月)부터는 급격(急激)히 자라난다. 2. 가해기간중(加害期間中)의 충영내(虫癭內) 솔잎혹파리 유충수(幼虫數)는 감소(減少)되지 않는다. 3. 솔잎혹파리의 피해엽(被害葉)은 충영(虫癭)이 형성(形成)되기 시작하면 길이 생장(生長)이 정지(停止)된다. 4. 서울지방(地方)에서 솔잎혹파리를 편제(騙除)하기 위한 하기(夏期) 벌채(伐採)는 종한시기(終限時期) 9월(月)20일경(日頃)이며 이 때의 유충체장(幼虫體長)은1.4~1.5mm이다. 5. 수관(樹冠)의 층위별(層位別) 방향별(方向別) 신초(新梢)의 길이별(別)에 따른 솔잎혹파리의 피해(被害)는 차이(差異)가 없으며 수령(樹令)과 산복위치(山腹位置)에 따라 피해도(被害度)의 차이(差異)가 있다.

• Animal Bioscience
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• 제34권1호
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• pp.36-47
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• 2021

Objective: This study determined the optimal ratio of whole plant corn silage (WPCS) to corn stover (stems+leaves) silage (CSS) (WPCS:CSS) to reach the greatest profit of dairy farmers and evaluated its consequences with corn available for other purposes, enteric methane production and milk nitrogen efficiency (MNE) at varying milk production levels. Methods: An optimization model was developed. Chemical composition, rumen undegradable protein and metabolizable energy (ME) of WPCS and CSS from 4 cultivars were determined to provide data for the model. Results: At production levels of 0, 10, 20, and 30 kg milk/cow/d, the WPCS:CSS to maximize the profit of dairy farmers was 16:84, 22:78, 44:56, and 88:12, respectively, and the land area needed to grow corn plants was 4.5, 31.4, 33.4, and 30.3 ha, respectively. The amount of corn available (ton DM/ha/yr) for other purposes saved from this land area decreased with higher producing cows. However, compared with high producing cows (30 kg/d milk), more low producing cows (10 kg/d milk) and more land area to grow corn and soybeans was needed to produce the same total amount of milk. Extra land is available to grow corn for a higher milk production, leading to more corn available for other purposes. Increasing ME content of CSS decreased the land area needed, increased the profit of dairy farms and provided more corn available for other purposes. At the optimal WPCS:CSS, MNE and enteric methane production was greater, but methane production per kg milk was lower, for high producing cows. Conclusion: The WPCS:CSS to maximize the profit for dairy farms increases with decreased milk production levels. At a fixed total amount of milk being produced, high producing cows increase corn available for other purposes. At the optimal WPCS:CSS, methane emission intensity is smaller and MNE is greater for high producing cows.

• 인간식물환경학회지
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• 제24권5호
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• pp.451-460
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• 2021

Background and objective: The prolonged COVID-19 pandemic has had significant impacts on mental health, which has emerged as a major public health issue around the world. This study aimed to analyze trends and network structure of 'grow-your-own (GYO)' through Instagram, one of the most influential social media platforms, to encourage and sustain home gardening activities for promotion of emotional support and physical health. Methods: A total of 6,388 posts including keyword hashtags '#gyo' and '#growyourown' on Instagram from June 13, 2020 to April 13, 2021 were collected. Word embedding was performed using Word2Vec library, and 7 clusters were identified with K-means clustering: GYO, garden and gardening, allotment, kitchen garden, sustainability, urban gardening, etc. Moreover, we conducted social network analysis to determine the centrality of related words and visualized the results using Gephi 0.9.2. Results: The analysis showed that various combinations of words, such as #growourrownfood, #growourrownveggies, and #growwhatyoueat revealed preference and interest of users in GYO, and appeared to encourage their activities on Instagram. In particular, #gardeningtips, #greenfingers, #goodlife, #gardeninglife, #gardensofinstagram were found to express positive emotions and pride as a gardener by sharing their daily gardening lives. Users were participating in urban gardening through #allotment, #raisedbeds, #kitchengarden and we could identify trends toward self-sufficiency and sustainable living. Conclusion: Based on these findings, it is expected that the trend data of GYO, which is a form of urban gardening, can be used as the basic data to establish urban gardening plans considering each characteristic, such as the emotions and identity of participants as well as their dispositions.

• ALGAE
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• 제37권2호
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• pp.105-121
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• 2022

Modern seaweed farming relies heavily on seedlings from natural beds or vegetative cuttings from previous harvests. However, this farming method has some disadvantages, such as physiological variation in the seed stock and decreased genetic variability, which reduces the growth rate, carrageenan yield, and gel strength of the seaweeds. A new method of seedling production that is sustainable, scalable, and produces a large number of high-quality plantlets is needed to support the seaweed farming industry. Recent use of tissue culture and micropropagation techniques in eucheumatoid seaweed production has yielded promising results in increasing seed supply and growing uniform seedlings in large numbers in a shorter time. Several seaweed species have been successfully cultured and regenerated into new plantlets in laboratories using direct regeneration, callus culture, and protoplast culture. The use of biostimulants and plant growth regulators in culture media increases the seedling quality even further. Seedlings produced by micropropagation grew faster and had better biochemical properties than conventionally cultivated seedlings. Before being transferred to a land-based grow-out system or ocean nets for farming, tissue-cultured seedlings were recommended to undergo an acclimatization process to increase their survival rate. Regular monitoring is needed to prevent disease and pest infestations and grazing by herbivorous fish and turtles during the farming process. The current review discusses recent techniques for producing eucheumatoid and other valuable seaweed farming materials, emphasizing the efficiency of micropropagation and the transition from laboratory culture to cultivation in land-based or open-sea grow-out systems to elucidate optimal conditions for sustainable seaweed production.