• 한국균학회지
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• 제16권1호
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• pp.16-20
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• 1988

영지(靈芝)의 항암물질개량(抗癌物質改良)과 신품종(新品種)의 육성(育成)을 위(爲)한 (육종역법)育種方法으로 제시된 원형질체융합(原形質體融合)의 기초자료를 얻고자 영양요구성균주(營養要求性菌株)의 선발(選拔), 종간원형질체융합(種間原形質體融合)과 융합균주(融合菌株)의 선발(選拔)을 실험(實驗)하였다. 1. 돌연변이(突然變異) 대상체(對相體)로는 균사체(菌絲體), mutagen으로는 자외선(紫外線)을 사용하였는데 영양요구성균주(營養要求性菌株)의 유기율(誘起率)은5.78%이었다. 2. 영지(靈芝)와 잔나비걸상버섯간(間) 원형질체융합률(原形質體融合率)은 2.03%이었다. 3. 융합균주(融合菌株)는 환원균총(還元菌叢)의 생장속도(生長速度)와 형태(形態)를 비교(比較)하여 선발(選拔)하였고, 계대배양후(繼代培養後)의 형태(形態)와 esterase isozyme pattern의 분석(分析)에 의해서 확인(確認)하였으며, 참나무톱밥배지(培地)에서 재배(栽培)하여 자실체(子實體)를 관제(觀祭)하였다.

• 한국미생물·생명공학회지
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• 제11권3호
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• pp.233-239
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• 1983

Bacillus thuringiensis 3ab K- 3 균주를 28$^{\circ}C$에서 UV광으로 돌연변이를 유도한 다음에 42$^{\circ}C$에서 24개의 Temperature-sensitive(ts)돌연변이 균주를 분리하여 42$^{\circ}C$에서의 성장과 항생제 저항성에 대한 성격을 연구하였다. 24개의 ts 돌연변이 균주중에 13개의 ts돌연변이체는 42$^{\circ}C$의 제한온도에서 전혀 성장을 하지 않았으며, 나머지 11개의 돌연변이체는 성장이 28$^{\circ}C$에서 보다 1/2 에서 1/4까지 감축되었다. 이러한 성격에 따라서 ts돌연변이체는 치사군과 비 치사군으로 나눌수 있었다. 또한 B. thuringiensis SI K-2을 nitrosoguanidine으로 28$^{\circ}C$에서 처리하여 7개의 Auxotrophic mutant을 분리하였다. A-N28은 Arg$^{-}$ . Gly$^{-}$ , Leu$^{-}$ , Met$^{-}$ , Ser$^{-}$ , Val$^{-}$ 을 요구했고, A-N 65는 Ala $^{-}$ , Gly$^{-}$ , Leu$^{-}$ , Met$^{-}$ , Ser$^{-}$ , Val$^{-}$ 을 요구했으며 A-N 92는 Gly$^{-}$ , Leu$^{-}$ , Met$^{-}$ 을, A-N115는 7개의 아미노산을 A-N156은 8개를 요구했다. B. thuringiensis 3ab K-3와 SI K-2 는 Penicillin, Ampicillin과 Cephalothin에 저항성을 나타냈고 ts-U171, A-N92와 A-N115는 이 세항생제에 민감성을 나타냈다. Temperature - sensitive돌연변이균주를 42$^{\circ}C$에서 24시간 배양후에 28$^{\circ}C$로 옮기어 배양한 결과 ts-U601, -U603, -U604와 -U171은 성장을 더 이상하지 않았다.

• 미생물학회지
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• 제29권2호
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• pp.117-122
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• 1991

In order to improve the removal ability of phosphate, Spheroplast fusions were performed among auxotrophic mutants of Aeromonas hydrophila isolated from waste water, named A13 and A14, Aci37 auxotrophic mutant of Acinetobactercalcoaceticus, and auxotrophic E. coli HR262/pCE27 carring pit gene. Eight fusants obtained from this experiment showed different biochemical characteristics. When the rate of phosphate uptake among fusants (F1-F8) was investigated in Phosphate Uptake Medium (PUM), F8 strain showed the highest rate for phosphate removal, 7 times as much as control after two hours incubation. The role of cations ($Mg^{++}$ ,$Ca^{++}$ , $K^{+}$ in phosphate uptade by F8 was also investigated in PUM without each salt. $K^{+}$ seemed to be crucial. Being compared with phosphate untake rate in PUM, that in PUM without $K^{+}$ was reduced 1.5 times. Therefore, by applying F8 strain and $K^{+}$ in practical environmental system, the increased efficiency in phosphate removal can be derived.

• 한국식물병리학회지
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• 제10권1호
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• pp.39-46
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• 1994

Pseudomonas fluorescens Biovar III strains S-2 antagonistic to Rhizoctonia solani was subjected to Tn5 mutagenesis by the transposon vector pGS9. Ampicillin and kanamycin resistant (Ampr, Kmr) transconjugants were recovered at a frequency of 1.3$\times$10-7 per initial recipient cell, when recipient cells were washed twice in TE buffer before conjugation. Of the ca. 3000 transconjugants, a frequency of noninhibitory (Inh-), nonfluorescent (Flu-) and auxotorphic (Pro-) mutants were 0.27%, 0.47% and 0.40%, respectively. In these mutants, all Inh- mutants showed the same colony morphology as wild type, whereas all Flu- and Pro- mutants inhibited the growth of R. solani. These mutants were also susceptible to chloramphenicol, indicating only the Tn5 element, except for parts of pGS9, was integrated into the recipient genome. In a Southern blot analysis, the Tn5 element inserted into one site on the chromosome for each of the chosen mutants. However, Tn5 insertion sites of Inh-, and Pro- mutants were differed in each other. These indicate that the genes essential for R. solani inhibition, fluorescent production and auxotrophic are chromosomally located, but not linked to each other.

• 미생물학회지
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• 제16권3호
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• pp.111-121
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• 1978

About 40 temperature-sensitive mutants have been isolated as a preliminary step to study the spore germination, the cell cycle, and the control of macromolecular synthesis in Aspergillus nidulans. To obtain temperature-sensitive mutants rapidly and effectively, the selective enrichment method using antifungal antibiotic nystatin was developed. Based on the data which had applied to the concentration of auxotrophic mutants by the earlier investigators, the optimal concentration and the time of treatment at the nonpermissive temeprature were determined as 50 to 100 units per ml and 4.5 hr., respectively. Out of 41 ts mutants assigned to the strain symbol PK, thirteen that seemed to be arrested at the earlystage of spore germination were subjected to the further cytological and genetic analysis. Elght of these mutants are able to form germ tube and five not. Staining with acid fuchsin for the 5PK strains shows that one irreversible mutant, PK6 strain able to form germ tube, accumulate mitotic spindle, being arrested in mitosis. Another PK15 and PK23 strain have more than one intact nucleolus without germ tube formation at the restrictive temperature. the temperature-senstive mutation in PK12 strain, the onlystrain which is able occurred in certain gene specific for the germination of spore. All of the ts markers are recessive and complement each other in heterokaryon between two different ts markers at the restrictive temperature.

• 미생물학회지
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• 제26권2호
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• pp.82-87
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• 1988

The genetic analysis and characterization of protoplast fusion hybrids between complementary auxotrophic mutants of Candida pseudotropicalis were carried out. Nuclear fusion appeared to occur in fusion hybrids (e.g., F15 and F33), as strongly suggested by isolation of recombinants after mitotic segregation of parental genetic markers. This was confirmed by KNA content, nuclear staining and comparison of survival rate to UV light. After keeping fusion hybrids for approximately one year, the frequency of spontaneous mitotic segregation was $3.0\times 10^{-4}$ - $8.1\times 10^{-4}$ while that of induced mitotic segregation was $1.4\times 10^{-3}$- $1.7\times 10^{-3}$. These results suggested that they maintained stable karyogamy state. It was also found that the production of $\beta$-D-galactosidase from F15, F33 and F158 was somewhat increased when compared with that from either auxotrophic parents or wild type.

• 미생물학회지
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• 제27권2호
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• pp.98-107
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• 1989

Trichoderma koningii ATCC26113으로부터 얻어진 영양요구성 돌연변이주간의 종내 원형질체 융합을 시도하여 생성된 융합체의 유전자형을 완전평판배상에서 분석하였다. 생성된 융합체 중 모균고 다른 독립영양형 균주에서 섬유소 분해능이 증진된 융합체를 얻었으며 이들이 이배체(혹은 이수체)임을 확인하였다. 또한 이들 이배체(혹은 이수체)의 독립영양청 잡종의 원형 질체 융합을 통하여 유전자의 교환 및 재조합에 의하여 자연분리되므로써 형성됨을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.102-107
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• 1992

For the purpose of producing L-ornithine by microbial fermentation, mutant strains were developed from glutamate-producing bacteria by mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine (NTG) and UV irradiation. Brevibacterium ketoglutamicum BK1046, a L-citrulline auxotroph which is also resistant to arginine hydroxamate (Arghx), was isolated and selected as the best producer of L-ornithine. This strain was capable of producing L-ornithine at a concentration of 24 g/l after 69 hours of cultivation in the 21 jar fermentor. The optimum supplementary level of L-arginine, a substitute for L-citrulline, was found to be about 0.2 g/l in the shake-flask fermentation.

• 농업과학연구
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• 제15권1호
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• pp.15-22
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• 1988

팽이버섯 원형질체(原形質體)의 재생(再生)과 환원(還元)에 영향(影響)을 미치는 요인(要因)에 대해 조사(調査)하였으며 영양요구성(營養要求性) 돌연변이(突然變異) 균주(菌株) 선발(選拔)을 실시(實施)하여 얻은 결과(結果)는 다음과 같다. 1. 원형질체(原形質體) 재생배지(再生培地)에 첨가(添加)되는 삼투압 조절제(調節劑)로는 0.6M의 sucrose가 가장 우수(優秀)하였고 재생률(再生率)은 0.47~1.32%로 나타났다. 재생용(再生用) 배지(培地)에 몇가지의 영양원(營養源)을 첨가(添加)하였을때 재생률(再生率)의 증가(增加)를 나타내었으며 특히 yeast extract가 팽이버섯의 원형질체(原形質體) 재생(再生)에 효과적(效果的)이었다. 2. 팽이버섯의 원형질체(原形質體) 재생(再生) 형태(形態)는 bud-like cells에서 germ tube가 발달(發達)하는 형태(形態)이었다. 환원(還元)된 균총중(菌叢中)에는 13~18%의 clamp connection을 형성(形成)하지 않는 monokaryon 균주(菌株)들이 발견(發見)되었다. 3. 자외선(U.V.L) 조사시(照射時) 팽이버섯의 포자생존률(胞子生存率)은 180사(砂)에서 16%였고 이때 5계통(系統)의 영양요구성(營養要求性) 균주(菌株)가 선발(選拔)되었다. 이들 중(中) 2균주(菌株)는 nucleic acid requiring strain이었고 3균주(菌株)는 vitamine requiring strain이었다.

• 한국식품과학회지
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• 제21권1호
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• pp.37-44
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• 1989

Monascus 균주의 적색색소의 최적 생산조건을 규명하기 위하여, Monascus anka IFO 4478과 IFO 6540의 영양요구성 돌연변이주인 M. anka, 4478-27-37 $(Thi^-,\;Met^-),\;4478-27-62\;(Thi^-,\;Arg^-)$와 M. anka, 6540-185-24 $(Pan^-,\;Leu^-)$ 6540-185-72$(Arg^-)$의 균주를 이용하여 세포융합을 시도하였다. Protoplasts의 생성은 chitinase (10mg/ml), cellulase (5mg/ml) 및 ${\beta}-glucuronidase\;(5mg/ml)$의 혼합처리가 효과적이었고, 융합조건은 protoplasts를 30% PEG 6.000, $0.01M-CaCl_2$ 및 0.05M-glycine, pH 6.0으로 처리했을 때 융합빈도는 0.7%-0.85%이였다. 융합주 중에서 No. 14와 42의 색소 생산능이 가장 높았다.