• 미생물학회지
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• 제21권2호
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• pp.51-60
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• 1983

Cultural characteristics of Strptomyces griseolus isolated from the soil were investigated. This strain was disclosed to utilize D-xylose, and D-glactose in preference order as a carbon source with the formation of glucose isomerase. The addition of sweet potato starch also proved effective promoting the total enzyme activity measured at 29% higher than the control. Corn cob, one of waste agricultural resources, was hydrolyzed in 2~3% $H_2SO_4$ solution at $100^{\circ}C$, 3~5 hours to produce a xylose syrup which gave rise to the recovery of 19.9% in a batch system and 28.2% in a repeated system. By the addition of both 2% of xylose syrup(Be'28) prepared by and us 65% of corn steep liquor (total nitrogen 1.2%), enzyme induction was maximized. The enzyme activity was stimulated by the xylose and the cell growth by the C.S.L. Also, remarkable increase of enzyme activity was noticed by the addition of protein acid hydrolysate 86.2% higher than the control. $QO_2$ of the biomass cultured in 30L capacity jarfermentor recorded low oxygen requirement of 251.2 1/hr. Maximum activity of glucose isomerase was observed noted at the 9th hour after inoculation which is 2 hours faster than the stationery was observed noted at the 9th hour after inoculation which is 2 hours faster than the stationery phase of the biomass growth. Glucose isomerase from the strain was activated by adding the $Co^{++}\;and\;Mg^{++}$ with optimum temperature of $73^{\circ}C$ and pH of 7.2. Conversion ratio of 60% glucose to frutose was 42.5% after 70 hours reaction.

• 미생물학회지
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• 제41권3호
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• pp.164-167
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• 2005

Lepista nuda DGUM 26501의 균사 생육을 위한 배양조건 및 세포외 분비 효소 활성을 조사하였다. 균사 생육을 위한 최적 온도는 $24^{\circ}C$였고, pH$7.0\~8.0$에서 최적 균사 생육을 나타내었다. 적정 균사생육을 위한 산소분압은 $10\%$이상이었다. 최소배지로 Czapek-Dox 한천배지에 탄소원을 변경하여 첨가시, maltose, sucrose, manitol, xylitol 등이 우수하였다. 유기산으로 gluconate가 가장 우수한 균사 생육을 보여주었다. 전반적으로 유기질소원이 무기질소원보다 균사 생육이 더 우수하였으며, 유기질소원으로 corn steep liquor(CSL), soytone, protease peptone을 사용하였을 때 균사생육이 우수하였다. 사용한 인산원 중 ammonium phosphate, 비타민원으로 pyridoxine, riboflavin, nicotinic acid 첨가시 우수한 균사 생육을 보여주었다. $24^{\circ}C$에서 10일간 배양된 L. nuda DGUM 26501의 균사외 분비효소 중 $\alpha-amylase$의 활성도가 다른 효소에 비해 상대적으로 높았으며, lipase의 활성도는 미미하게 나타났다.

• Current Research on Agriculture and Life Sciences
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• 제14권
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• pp.111-122
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• 1996

Streptomyces chibaensis J-59 xylanase는 CSL 배지(1% corn steep liquor, 0.15% glucose, 0.1% $MgSO_4{\cdot}7H_2O$, pH 7.0)에서 1% xylan을 효소생산 유도물질로 첨가하였을 경우에 생산(0.83 unit/ml) 되었으나, xylose를 비롯한 각 종 탄소원을 포함하는 배지에서는 효소가 생산되지 않았다. S. chibaensis로 부터 생산된 세포외 xylanase를 $(NH_4)_2SO_4$ 분획침전, DEAE-Sephadex A-50 column chromatography, Sephadex G-200 gel filtration 과정으로 약 29%의 수율로 20배 정제하였다. 정제한 xylanase는 SDS-PAGE 및 Sephadex G-200 gel filtraion에서 분자량이 모두 25,000 Da으로 나타나 monomenc enzyme으로 확인되었다. 금속이온에 대한 영향은 $Fe^{3+}$, $Hg^{2+}$, $Cu^{2+}$, sodium dodecyl sulfate, N-bromosuccinide 등에서는 아주 강한 저해를 받았고, $Mn^{2+}$, $Zn^{2+}$에서는 약간의 저해를 받았다. 반면에 $Mg^{2+}$는 효소활성을 증가시켰다. Xylanase에 의한 xylooligo 당의 생산양상을 TLC로 조사한 결과 xylobiose, xylotriose 및 xylotetrose가 주 생산물이었으며, 반응 1시간 이후부터 소량의 xylose가 생성되었다. 따라서 본 효소는 전형적인 endotype xylanase로 확인되었으며 새로운 기능성식품인 자일로 올리고당(xylooligo-saccharides)의 제조에 이용할 수 있을 것이다.

• 생명과학회지
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• 제7권1호
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• pp.30-38
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• 1997

내열성 {\alpha}$-amulase를 생산하는 미생물을 분리하기 위하여 각종 분리원으로 시료를 채취하여 55$^{\circ}C$ 이상에서 생육하고 가장 내열성 {\alpha}$-amulase 생산능이 우수한 균주를 분리, 동정한 결과 thermophilic Bacilus 속으로 추정되었다. 균체생육과 효소생산의 최적온도는 60~$65^{\circ}C$였고, 초발 pH8.0에서 가장 높은 효소생산능을 보였다. {\alpha}$-amulase 생산에 가장 양호한 탄소원은 soluble starch, dextrin, prtato starch, corn starch 등의 다당류이었으며 glucose, fructose 등의 단당류에서는 효소생산이 미약하거나 억제를 받았다. {\alpha}$-amulase 생산에 가장 중요한 질소원은 yeast extract이었따. 0.1% $CaCl_2{\cdot}2H_2O$, 0.001%의 Tween-80의 첨가는 {\alpha}$-amulase 생산성을 증가시켰다. 본 공사균이 생산한 조효소액의 특성을 검토해 본 결과, 8$0^{\circ}C$에서 최적 효소활성을 보였으며, 10$0^{\circ}C$에서도 23%의 잔존활성을 나타내었다. 최적 pH는 5.0이었다. $Ca^{2+}$은 효소활성 증진에는 영향을 미치지 않았다. 공시균으로부터 분리한 genomic DNA를 중온성 BAcillus subtilis KCTC 1024에 형질전환시킨 결과, transformant는 wild type에 비하여 약 2배의 효소활성이 증가되었다.

• KSBB Journal
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• 제14권2호
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• pp.181-187
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• 1999

젖산 생산에 큰 비중을 차지하는 원료비용 절감을 위한 다양한 공업적 질소원의 이용 가능성을 조사하였다. CSL를 사용하여 회분 발효한 결과, CSL 5%배지 발효시 높은 생산성을 보였으며, 정제 CSL을 사용한 배지에서 젖산 생산성은 CSL보다 약 1.21 배 증가율을 보였다. Yeast extract와 CSL 혼합질소원의 배지조성을 변화시켜 LBM5의 젖산 생성정도를 알아본 결과, 조성 비율 1:8일 때 우수한 발효율을 관찰 할 수 있었다. 발효 폐기물의 대체 질소원 사용가능성을 조사하기 위하여 맥주공장에서 부산물로 배출되는 폐효모를 이용하여 발효시에도 CSL 5%와 비슷한 발효율을 얻었다 연속발효 수행결과, 최적의 희석율은 0.05-0.065-1h였으며 젖산 생산성에 있어서 회분발효보다 1.93.0배증가하였다. 한편 초기 순수배지에 들어가는 yeast extract양의 1/3-2/3를 발효폐액에 첨가하여 회분발효 및 연속발효 실험을 수행하여 높은 젖산 생산성을 얻으므로써 공정상 원료비 절감효과를 기대할 수 있어으며 잔류 영양분을 재사용함으로써 폐액량 감소에 따른 처리비용 절감이라는 이중적인 효과를 얻게 되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.289-295
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• 2005

In this study, the cultural medium used for the efficient production of $\gamma$-PGA with a newly isolated Bacillus sp. RKY3 was optimized. It was necessary to supplement the culture medium with L-glutamic acid and an additional carbon source in order to induce the effective production of $\gamma$-PGA. The amount of $\gamma$-PGA increased with the addition of L-glutamic acid to the medium. The addition of 90 g/L L-glutamic acid to the medium resulted in the maximal yield of $\gamma$-PGA (83.2 g/L). The optimum nitrogen source was determined to be peptone, but corn steep liquor, a cheap nutrient, was also found to be effective for $\gamma$-PGA production. Both the $\gamma$-PGA production and cell growth increased rapidly with the addition of small amounts of $K_2HPO_4$ and $MgSO_4\cdot7H_{2}O$. Bacillus sp. RKY3 appears to require $Mg^{2+}$, rather than $Mn^{2+}$, for $\gamma$-PGA production, which is distinct from the production protocols associated with other, previously reported bacteria. Bacillus sp. RKY3 may also have contributed some minor $\gamma$-PGA depolymerase activity, resulting in the reduction of the molecular weight of the produced $\gamma$-PGA at the end of fermentation.

• KSBB Journal
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• 제29권3호
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• pp.165-178
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• 2014

Statistical medium optimization has been carried out for the production of succinic acid in anaerobic fermentations of Actinobacillus succinogenes. Succinic acid utilized as a precursor of many industrially important chemicals is a fourcarbon dicarboxylic acid, biosynthesized as one of the fermentation products of anaerobic metabolism by A. succinogenes. Through OFAT (one factor at a time) experiments, corn steep liquor (CSL), a very cheap agricultural byproduct, was found to have significant effects on enhanced production of succinic acid, when supplemented along with yeast extract. Hence, using these factors including glucose as a carbon/energy source, interactive effects were investigated through $2^n$ full factorial design (FFD) experiments, showing that the concentration of each component (i.e., glucose, yeast extract and CSL) should be higher. Further statistical experiments were conducted along the steepest ascent path, followed by response surface method (RSM) in order to find out optimal concentrations of each constituent. Consequently, optimized concentrations of glucose, yeast extract and CSL were observed to be 180 g/L, 15.08 g/L and 20.75 g/L respectively (10 g/L of $NaHCO_3$ and 100 g/L of $MgCO_3$ to be supplemented as bicarbonate suppliers), with the estimated production level of succinic acid to be 92.9 g/L (about 3.5 fold higher productivity as compared to the initial medium). Notably, the RSM-estimated production level was almost similar to the amount of succinic acid (92.9 g/L vs. 89.1 g/L) produced through the actual fermentation process performed using the statistically optimized production medium.

• 생약학회지
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• 제17권1호
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• pp.23-34
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• 1986

To find antitumor components of Lyophyllum decastes, the mycelia of L. decastes were cultured in artificial media and a new antitumor component which showed potent antitumor activity against sarcoma 180 implanted in mice, was isolated and named 'Lyophyllan A'. Lyophyllan A was composed of a polysaccharide moiety (86%) and a protein moiety (2%). The polysaccharide moiety was found to be a heteroglycan which consisted of glucose (48.1%), mannose (30.8%), galactose, xylose and fucose. The protein moiety contained 18 amino acids. Cultural characteristics of L. decastes were investigated by shake culture method. The best result was obtained when L. decastes was cultured in medium glucose 50g, peptone 10g, corn steep liquor 30ml, $KH_2PO_4$ 0.87g, $MgSO_4$ $7H_2O$ 0.5g, $CaCl_2$ 0.3g, $FeSO_4{\cdot}7H_2O$ 10mg, $MnCl_2{\cdot}4H_2O$ 7mg, $ZnSO_4{\cdot}7H_2O$ 4mg and $CuSO_4{\cdot}5H_2O$ 1mg per one liter at $26^{circ}C$, 180rpm, for 9 days.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.812-818
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• 2001

Alginate and alginate-derived oligomannuronate enhanced penicillin production in shake flask and fermentor cultures of Penicillium chrysogenum Wis 54-1255 (containing a single copy of the penicillin gene cluster) and in the high producter strain P. chrysogenum AS-P-99 (containing multiple copies of the penicillin gene cluster). Alginate was not used as a single carbon source by P. chryogenum. The stimulatory effect on penicillin production was observed in a defined medium and, to a lower extent, in a complex production medium containing corn steep liquor. Alginate-supplemented cells showed higher transcript levels of the three penicillin biosynthetic genes, pcbAB, pcbC, and penDE, than cells grown in the absence of alginate. The promoters of the pcbAB, pcbC, and penDE genes were coupled to the reporter lacZ gene and introduced as monocopy constructions in P. chrysogenum Wis 54-1225 npe10 by targeted integration in the pyrG locus; the reporter ${\beta}$-galactosidase activity expressed from the three promoters was stimulated by alginate added to the culture medium of the transformants. These results indicate that the stimulation of penicillin production by alginate was derived from an increase in the transcriptional activity of the penicillin biosynthesis genes. The induction by alginate of the transcription of the three penicillin biosynthetic genes is good example of the coordinated induction of secondary metabolism genes by elicitors of plant (or microbial) origin.

• KSBB Journal
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• 제17권4호
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• pp.333-338
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• 2002

생분해성 고분자 합성물질의 원료가 되는 젖산을 주로 생산하는 균을 김치로부터 분리하였다 SEM을 사용하여 관찰한 분리한 균의 형태는 연쇄간균이었고 165 rRNA sequencing 에 의해 계통발생학적 분석의 결과 Lactobacillus casei KH-1로 명명하였다. 1. casei KH-1는 g1ucose를 젖산으로 98%를 전환시키는 호모발효균이었으며, D(-)와 L(+)-이성질체를 각각 7%와 93%를 포함하는 racemic mixtrure로 젖산을 생산하였다. L. casei KH-1은 다른 lactobacillus속과는 달리 세포의 성장과 젖산의 생산에 기질로서 lactose를 이용하지 못하였지만 glucose의 이용은 이전의 연구들과 비교할 때 효과적이었다. Lactobacillus속의 배양에 사용되는 MRS배지의 질소원을 저렴한 원료 즉, YE와 CSL를 1:1로 첨가한 배지로 대신하여 최대의 젖산수율(1.09 mole .mole$^{-1}$)을 얻어 젖산발효에 효과적인 질소원의 대체가 이루어졌다