• 한국미생물·생명공학회지
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• 제16권2호
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• pp.105-110
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• 1988

전분이용성 세포융합 효모를 이용하여 단세포단백질 생산을 위한 기초실험을 행하였다. 전분배지에서 균체생성이 우수한 fusant12 균주의 배양조건은 최적질소원 (NH$_4$)$_2$SO$_4$ 0.1%, 최적 soluble starch 농도 7%, 최적 초기pH5.6이었다. Fusant12균체의 자기소화에 의한 가용성 단백질의 추출은 효모현탁액에 ethyl acetate를 5%(v/ v)되게 첨가하여 30min간 액화전처리과정을 행하므로 효과적으로 얻을 수 있었다. 전분이용성 효모인 fusant 12균주와 비전분이용성 효모인 Torulopsis candida의 혼합배양으로 균체생성량을 증가시킬 수 있었으며, 혼합배양시 종균접종혼합비는 6대4일 때 효과적이었다. Fusant 12균주 단독 및 Torulopsis candida와의 혼합배양시 tapioca 배지에서의 균체생성량은 soluble starch 배지에서 보다 약 2.5배 증가하였다. 건조균체의 조단백질함량은 39%, 핵산함량은 5.8%이고 균체단백질은 FAO 표준단백질과 비교하여 필수아미노산중 methionine 함량이 낮으며, Iysine 함량은 높았다.

• 약학회지
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• 제38권6호
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• pp.749-755
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• 1994

An interspecific fusant strain, Streptomyces MS1 was obtained by protoplast fusion between S. peucetius subsp. caesius and S. platensis. We studied on the fermentation characteristics of the fusant strain. The fermentation products of the fusant MS1 was identical with S. peucetius, but its production of anthracycline was more stable than S. peucetius under various fermentation conditions in regard to acidogenesis of fermentation broth. The optimal medium composition for anthracycline production by fusant MS1 as follows: sucrose 2.0%, glucose 1.0%, soytone 0.7%, $CaCO_3$ 0.2%, $KH_2PO_4$ 0.013%, casamino acids 0.01%, $K_2SO_4$ 0.025%, $MaCl_2\;6H_2O$ 1.024%, 5M $CaCl_2\;5H_2O$ 0.4%, 1N NaOH 0.7%, 20% L-proline 1.5%. In this condition, the productivity of anthracycline was $80{\sim}100\;{\mu}g/ml$.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1077-1085
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• 1997

This study was carried out to elucidate the utilization of the fusant for shortening the ripening time by making an observation of the microstructure and the profile of component change. In ripening cheese, moisture content of the sample treated with tested strain is not a remarkable difference among the test samples. With an increase of the ripening time, L. helveticus showed the highest increase in protein content, followed by fusant, and then L. bulgaricus. The fat content of all starters was gradually decreased while it was it was rapidly decreased after 7 days. The pH of all starters was gradually decreased when the ripening time increased. The titratable acidity was greatly increased between a 9th day and a 15th day ripening. In investigating the light microscopic microstructure of ripened cheese samples, the sample treated with fusant indicated little difference from the other starters in decomposition of protein and fat components by microbial enzymes. In SEM observation, the structure of all cheese samples was uniform and the rough texture was converted into smooth texture by the interaction of cheese components and the abscission of single bond in casein matrix when the ripening time is increased. The fusant showed similar results in the examination of component change and its microstructure compared with the other starters. Therefore, it was revealed that the fusant can be partially used as a cheese starter instead of conventional starters by replacing them or combining them together with the other starters for shortening the ripening time.

• 한국식품영양과학회지
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• 제24권5호
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• pp.779-784
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• 1995

5'-GMP(5'-Guanylic acid) 생산 융합균조 fusant RC102를 고정화하여 5'-GMP을 연속적으로 생산하고자 하였다. 균체 고정화용 담체로서 k-carrageenan, polyacrylamide, Ca-alginate 및 agar 등 4가지 담체에 고정화한 결과 최적 담체로서 3% k-carrageenan을 선정하였으며, 이담체에 고정화한 균체를 이용하여 5'-GMP 연속적으로 생산하였다. 고정화 균체에 의한 5'-GMP 생산의 최적 온도 및 pH은 $32^{\circ}C$, pH 8.0, 미량온소로서 $Mn^{2+}과\;Zn^{2+}$의 농도는 각각 $30\mu\textrm{g}/L,\;1{\times}10^{-6}%$이었다. $Mn^{2+}$이 풍부하고 값싼 CSL(Corn Steep Liquor)을 배지로서 사용하기 위해서 penicillin G와 D-cycloserine 및 POSEA(polyoxyethylene stearylamine) 농도 최적 농도는 각각 0.8unit/ml, 0.8unit/ml, 그리고 5mg/ml으로 나타났으며, 항생물질 보다 계면활성제가 효과적이었다. 이상의 최적 조건에서 고정화 fusant RC102는 15일간 안정되게 5'-GMP를 생산하였다.

• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.108-114
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• 1992

The fermentative characteristics in ethanol production from lactose, with increased ethanol tolerance, of a fusant yeast strain constructed by protoplast fusion of Saccharomyces cerevisiae and Kluyveromyces fragilis were studied. The ethanol tolerance of this strain was increased to 8.0%, compared with the parent K. fragilis. During batch ethanol fermentation the optimal cultivation conditions for this fusant yeast were an initial pH of 4.5, a culture temperature $30^\circ{C}$. stirring at 100 rpm without aeration in 10% lactose medium (supplied with 1.0% yeast extract). Using this fusant strain in whey fermentation to ethanol, maximum ethanol production reached 3.41% (w/v) (theoretical yield; 66.7%) after a 48 hour cultivation period.

• 약학회지
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• 제38권6호
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• pp.696-702
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• 1994

An interspecific fusant strain, MS1, was obtained by protoplast fusion between S. peucetius subsp. caesius and S. platensis. We studied on the microbiological and cultural characteristics of the fusant MS1. In liquid culture, the viscosity of culture broth of S. peucetius increased during incubation However the fusant MS1 formed pellet like S. platensis without viscosity change. On agar medium the colony morphology of MSI resembled S. platensis but the color was similar to S. peucetius. The fermentation products of the fusant MS1 was identical with S. peucetius.

• 한국미생물·생명공학회지
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• 제21권4호
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• pp.310-315
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• 1993

An interspecific fusant was made from the protoplasts of two strains of Lactobacillus genus (L. bulgaricus and L.helveticus). And in order to test the applicability of the fusant in manufacturing the cheddar cheese, functional properties of the strain was examined by determining acid-producing activity, three important enzyme activities and volatile free fatty acid-producing activity. The recombinant strain did not exhibit greatly increased acid-porducing activity. Lipase and volatile free fatty acid-porducing abilities of the fusant, however, were remarkably higher than those of the two parental strains. The fusant actually porduced the cheese porduct of the highest ammount of total volatile free fatty acid after 7 days ripening at 10$^{\circ}C$. Finally, the cheddar cheese ripened with this strain was also evaluated to be high preference and flavor intensity by organoleptic panel tests.

• 한국미생물·생명공학회지
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• 제14권5호
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• pp.359-363
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• 1986

본 실험의 목적은 starch의 alcohol발효에 있어서 전분의 $\alpha$-1.4 linkage을 분해하여 alcohol발효를 하는 S diastaticus와 전분 중의 $\alpha$-1.4, $\alpha$-1.6 linkage를 모두 분해할 수 있는 C. tropicalis 간의 이속간의 protoplast fusion을 시켰다. 이때 세포 융합의 빈도는 $10^{-5}$-$10^{-6}$이였으며, 이틀 융합체중 amylase 생성능과 유전적으로 안정한 융합체를 분리하였다. fusant의 성질을 조사하기 위하여 탄소원 자화능을 조사한바 parent와 달리 탄소원 자화능이 일부 보완됨을 보였고 또한 fusant는 원 parent보다 세포의 크기가 클 뿐만아니라, DNA함량도 많았다. spore형성능은 S. diastaticus A4는 spore를 형성하나 C. tropicalis는 형성할 수 없는 반면에 fusant는 형성하였고, Cu$^{++}$ 내성과 NaCl 내염성도 조사하였는데 fusant는 parent의 중간 성질을 가졌다. Fusant의 증식율을 조사하기 위하여 생육도를 조사한 결과 Parent보다 유도기가 길었음을 알았다.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1068-1076
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• 1997

This study was carried out to elucidate the utility of fusant for shortening the ripening time of imitation processed cheese. L. bulgaricus exhibited the highest protease and lactase activity and L. helveticus revealed the highest lipase activity. Fusant was shown to be high in the activity of protease and lactase. The total volatile free fatty acid produced by the cheese treated with L. helveticus was markedly increased after four ripening days and was gently increased after nine ripening days. However, L. bulgaricus significantly increased the total volatile free fatty acid between four and nine ripening days. In the case of fusant, the amount of total volatile free fatty acid was observed to increase at a constant rate relative to the ripening time. In free fatty acid production at different ripening times, L. bulfaricus generated caproic acid and caprilic acid abundantly while it produced a poor quantity of capric acid, lauric acid, and myristic acid. In the cheese sample treated with L. helveticus, the amount of caproic acid and capylic acid was on increase as the ripening time increased. The amount of caproic acid and caprylic acid produced by fusant was less than that produced by the other two starters. In the panel sensory evaluation, the flavor intensity and preference increased as the ripening time increased. The cheese sample treated with fusant showed the highest flavor intensity at 7 days, whereas cheese treated with L. helveticus exhibited the highest flavor intensity at 15 or 30 days. The cheese treated with L. helveticus showed the highest preference at 7 days, but cheese treated with fusant exhibited the highest preference at 30 days.

• 한국미생물·생명공학회지
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• 제16권4호
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• pp.297-302
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• 1988

고온발효성인 Sacch. cerevisiae D-71과 내삼투압성인 Zygosacch. rouxii SR-S를 세포융합시킨 후 유전적으로 안정한 융합주 FS-RN1를 선별하여 각종 특성을 조사하였다. FS-RN-1은 이를 4$^{\circ}C$에서 6개월 보관했을 때 5.8%의 친주복귀율을 보여 유전적으로 안정하였고 친주에 비하여 세포체적이 컸고 DNA 함량이 많았으며 유도기가 다소 길었다. 또한 FS-RN1은 TTC 정색 시험에서 홍색을 띠었고 5% NaCl 함유되어 있는 간장국가수분해액의 한천배지에서 포자를 형성하였다. FS-RN1의 NaCl에 대한 내성은 친주의 중간이었으나 탄소원 자화성, KC1과 sodium propionate 및 cycloheximide 내성은 친주중 어느 한쪽의 성질을 띠었다. FS-RN1를 72시간 배양한 후 회수한 세포를 ethyl acetate로 처리한 세포현탁액의 $\beta$-fructofuranosidase 활성은 건물 g당 24.2$\times$$10^{-3}$ IU로 친주보다 훨씬 높았다. 또한 FS-RN1의 발효력은 40% glucose와 20% sucrose를 3$0^{\circ}C$에서 4일간 발효시켰을 때 각각 6.0%(v/v)와 8.8%(v/v)의 에탄올을 생성하여 친주보다 높았다.