• Mycobiology
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• 제49권5호
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• pp.491-497
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• 2021

An endolichenic fungus Xylaria grammica EL000614 produces grammicin, a potent nematicidal pyrone derivative that can serve as a new control option for root-knot nematodes. We optimized an Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for X. grammica to support genetic studies. Transformants were successfully generated after co-cultivation of homogenized young mycelia of X. grammica with A. tumefaciens strain AGL-1 carrying a binary vector that contains the bacterial hygromycin B phosphotransferase (hph) gene and the eGFP gene in T-DNA. The resulting transformants were mitotically stable, and PCR analysis showed the integratin of both genes in the genome of transformants. Expression of eGFP was confirmed via fluorescence microscopy. Southern analysis showed that 131 (78.9%) out of 166 transformants contained a single T-DNA insertion. Crucial factors for producing predominantly single T-DNA transformants include 48 h of co-cultivation, pretreatment of A. tumefaciens cells with acetosyringone before co-cultivation, and using freshly prepared mycelia. The established ATMT protocol offers an efficient tool for random insertional mutagenesis and gene transfer in studying the biology and ecology of X. grammica.

• 한국식품과학회지
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• 제45권1호
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• pp.13-19
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• 2013

반응표면분석법을 이용하여 적양배추 종자의 전자선 처리조건과 재배조건에 따른 새싹채소의 이화학적 및 관능적 품질특성을 분석하여 유통에 적합한 최적조건을 모색하였다. 수분함량의 경우 회귀식의 $R^2$가 0.9638이었고 조사선량 및 재배기간에 많은 영향을 받고 있었다. Total phenolics 함량은 회귀식의 $R^2$가 0.9117이었고 조사선량에 많은 영향을 받았으며, carotenoid 함량($R^2$=0.8338)의 경우 조사선량, 재배기간, 저장기간의 순으로 조건 변수의 영향력이 작용하였다. 관능적 품질 역시 전자선 조사선량에 가장 크게 영향을 받아 선량의 증가에 따라 관능평점이 감소하는 경향을 보여주었다. 재배 및 저장조건의 최적화를 위해 total phenolics 함량 및 전반적 기호도를 superimposing한 결과 최적조건은 조사선량 2.2-3.8 kGy, 재배기간 3.0-4.0일 및 저장기간 2.0-3.0일 범위로 예측되었다.

• KSBB Journal
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• 제17권3호
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• pp.228-234
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• 2002

Factorial design model을 이용하여 A. xylinum KJ1의 BC생산을 위한 최적 배양조건을 결정하였다. 요인 분석을 위한 실험 계획법으로는 부분요인 분석을 통한 factorial model을 이용하였으며, 주요 실험인자인 탄소원 농도, 교반속도(rpm), 산소분압, CSL의 농도의 네 가지 factor의 영향에 의한 BC생산량의 변화를 측정하였다. SAS 프로그램을 이용하여 전체 24개의 실험계획에서 각각의 factor의 조합에 의한 BC 생산성에 관한 결과 및 예측값을 비교한 결과 BC 생산량 면에서는 상관계수($R^2$)가 0.91으로 이었고, 수율면에서는 상관계수($R^2$)는 0.81이다. 최적 BC 생산을 위한 각 factor들이 탄소원의 농도 4%, 교반속도 460 rpm, 산소분압 0.28 atm, CSL 농도 6%일 때, 이때의 BC 생산량은 11.67 g/L로 예측되었다. 그리고 BC 생산 수율면에서 최적 배양조건이 탄소원 농도 4%, 교반속도 564 rpm, 산소분압 0.21 atm, CSL 농도 2%일 때 최적의 수율 0.42 g/g를 얻을 수 있을 것으로 예측되었다. 결정된 최적 조건에서의 실증 실험 결과 11.47 g/L의 BC 생산량을 얻을 수 있었으며, 이는 fermentor상에서의 기본실험에서 얻은 4.83 g/L보다 2.4배 이상 향상된 결과이다.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.993-997
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• 2003

Response surface methodology was applied to find the optimum conditions for the production of DXAMase (containing both dextranase and amylase activities) based on the cultivation variables (pH, temperature, and agitation rate). The experimental values from the model equation conceded with predicted values in which the predicted values for dextranase and amylase activities were 2.26 and 3.52 U/ml at pH 4, $28^{\circ}C$, 235 rpm, and the corresponding experimental values were 2.41 and 3.68 U/ml, respectively.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.525-531
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• 2010

This work was aimed at utilizing rice bran as a substrate for $\beta$-carotene production by Rhodotorula glutinis DM 28 under optimized conditions of solid-state fermentation. The biomass and $\beta$-carotene content of Rhodotorula glutinis DM 28 grown on rice bran as a sole substrate under solid-state fermentation were 54 g/kg rice bran and 1.65 mg/kg rice bran, respectively. Its biomass and $\beta$-carotene content, however, could be improved by 60% and 30%, respectively, using the Central Composite Design for the optimization of its cultivation conditions. The optimized conditions obtained were a pH of 5, a moisture content of 70% (w/w), and a carbon-to-nitrogen ratio of 4. Under these conditions, rice bran containing R. glutinis DM 28 had nutritional values of $\beta$-carotene, protein, and fat higher than those of rice bran alone. Yeast-grown rice bran could be suitable, therefore, to use as a $\beta$-carotene-enriched supplement in animal feeds.

• Korean Chemical Engineering Research
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• 제53권3호
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• pp.321-326
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• 2015

Plackett-Burman (PB) and Box-Behnken (BB) experimental designs were used to optimize fermentation variables for the biotransformation of glycyrrhizin (GL) to monoglucuronyl-glycyrrhetinic acid (MGGA). The PB design was first used to screen the important factors among the medium variables. The steepest ascent method was used to approach the optimum range for each of these factors. The BB design was finally used to analyze the response surfaces of the screened factors for further optimization. The optimized conditions for this system were 0.7 g/L $MgSO_4{\cdot}7H_2O$, 1.19 g/L GL, and cultivation for six days. The biotransformation of GL to MGGA could reach up to 35.72%, which is a good result for this kind of transformation.

• Journal of Plant Biotechnology
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• 제2권3호
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• pp.157-163
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• 2000

Optimization of chemicals in the large scale sea water medium and inoculum for biomass and natural colourants production in the marine cyanobacteria, Phomidium tenue BDU 46241 (phycoerythrin producer) and P.valderianum BDU 30501 (phycocyanin producer) was carried out by experiments in L8 orthogonal array. Mathematical analysis revealed the significance of these factors. The factor(s) that critically control the yield varied with the organism and the end-product further, the desirable level of these factors between the normal and a higher level tested was identified and improved media were evolved. In both cyanobacteria, higher level of $K_2$$HPO_4$, $NaNO_3$ and inoculum with normal level of ferric ammonium citrate was found to be desirable for biomass production and additionally, higher level of $MgSO_4$ for pigment production. The level of other factors varied with the organism and the end-product. Confirmation experiments showed that the clues obtained based on mathematical experimentation are valid. In P.tenue, the medium optimized for biomass production increased the yield of biomass by 495% and the medium optimized for phycoerythrin production increased the yield of biomass by 408% with 30% increase in phycoerythrin content of the biomass. Similarly in P.valderianum, the medium optimized for biomass production increased the yield of biomass by 224% and the medium optimized for phycocyanin production increased the yield of biomass by 143% with 44% increase in phycocyanin content of the biomass.

• 한국미생물·생명공학회지
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• 제26권3호
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• pp.226-231
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• 1998

청국장으로부터 분리한 체내혈액의 응고기작에 의해 생성된 단백질인 fibrin을 분해할 수 있는 효소를 분비하는 Bacillus subtilis KCK-7을 이용하여 fibrinolytic enzyme의 생성을 위한 최적 배지조건을 조사하였다. 탄소원으로서 soluble starch 5%와 cellobiose 0.5% 첨가시 가장 높은 효소생성을 보였으며, 질소원으로는 peptone, 생대두분이 우수하였고 특히, 생대두분 2% 첨가시에 가장 높은 효과를 보였다. 최적 배지조건은 0.5% peptone, 0.3% beef extract, 0.5% cellobiose, 5% soluble starch, 2% soybean meal, 0.02% $Na_2$HPO$_4$이었다. 본 배지를 효소생산용 배지로 사용할 때 배양 48시간에 효소생성이 가장 높은 것으로 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권6호
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• pp.313-321
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• 2003

This review summarizes the recent advances in high-density algal cultures in the field of algal biotechnology. Photobioreactor engineering for economical and effective utilization of algae and its products has made impressive and promising progress. Bioprocess engineers have expedited the design and the operation of algal cultivation systems. Many of them in use today are open systems due to cost considerations, and closed photobioreactors have recently attracted a considerable attention for the production of valuable biochemicals or for special applications. For high-density cultures, the optimization of environmental factors in the photobioreactors have been explored, including light delivery, CO$_2$and O$_2$gas transfer, medium supply, mixing and temperature. It is expected that further advanced photobioreactor engineering will enable the commercialization of noble algal products within the next decade.

• 수산해양교육연구
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• 제26권2호
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• pp.444-454
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• 2014

The range of optimization problem in aquaculture is very wide, resulting from the range of species, mode of operation. Quite a few studies focus marine net-cages, but studies on land based culture farm are few or no. This paper considers a allocation problem to meet production planning in land based aquaculture system. A water pool allocation model in land based aquaculture system was developed. The solution finds the value of decision variable to minimize yearly production costs that sums up the water pool usage cost and sorting cost. The model inputs were (1) the fish growth rate (2) critical standing corp (3) number of water pool (4) number of fish. The model outputs were (5) number of water pool in growing phase (6) cost of cultivation (6) optimal facility allocation(number of water pool for each growing phase). To solve the problem, an efficient heuristic algorithm based on a greedy manner is developed. Branch and bound and heuristic is evaluated through numerical examples.