• 한국작물학회지
• /
• 제57권3호
• /
• pp.226-232
• /
• 2012

Through the sampling four rice cultivars with differing amylose contents, the relationship between the structural and gelatinization properties of endosperm starches was analyzed. These rice varieties exhibited different chain length distribution ratio within the amylopectin cluster as well as varing amylose levels. The proportion of amylopectin short chains of in Goami cutlivars was higher than the other varieties, whereas the Goami 2 which shows amylose extender mutant properties in the endosperm showed the highest proportion of long chains. In X-ray diffraction analysis of rice starches, the Goami 2 variety displayed a B-type pattern whereas the other varieties were all A-type. Among the cultivars with high and normal rice starch levels, those with the higher amylose contents showed distinctly lower swelling. Goami 2 rice was found to have the highest onset and peak gelatinization temperature from the differential scanning calorimetry results. The four rice cultivars under analysis also showed different rates of hydrolysis by amyloglucosidase. These findings suggest that the composition and chemical structure of the starch content is a major determinant of both the gelatinization and functional properties of rice.

• Journal of Microbiology and Biotechnology
• /
• 제3권4호
• /
• pp.232-237
• /
• 1993

A strain of yeast which can convert starch directly to ethanol was developed by the intergeneric protoplast fusion between Schwanniomyces alluvius possessing $\alpha$ amylase as well as glucoamylase with debranching activity and FSC-14-75 which previously had been formed from a heterologous transformation and subsequent intergeneric protoplast fusion. Fusants were selected on minimal medium after protoplasts of auxotrophic mutant of S. alluvius fused with heat-treated protoplasts of FSC-14-75 in the presence of 30%(w/v) PEG and 20 mM $CaCl_2$. The fusion frequency was in the range of $10^{-6}$ order. All fusants tested were intermediate types of parental strains for carbon compound assimilation, and their cell volumes were approximately 1.1 times larger than FSC-14-75 and 1.8 times larger than S. alluvius. The fusants were unable to sporulate like FSC-14-75, while S. alluvius could sporulate. In flask scale the most promising fusant, FSCSa-R10-6, produced 7.83%(v/v) and 10.17%(v/v) ethanol from 15% and 20% of liquefied potato starch, respectively, indicating that the fermetation efficiency of each case increased 1.2 times and 1.6 times than that of FSC-14-75. The elution pattern on DEAE-cellulose chromatography showed that FSCSa-R10-6 has four distinct amylase peaks of which two peaks originated from S. alluvius and the other two from FSC-14-75. These results suggest that the enhanced fermentation efficiency of the fusant might be due to almost-complemented parental amylases.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.207-207
• /
• 2022

Eating and cooking quality (ECQ) is one of the most complex quantitative traits in rice. The understanding of genetic regulation of transcript expression levels attributing to phenotypic variation in ECQ traits is limited. We integrated whole-genome resequencing, transcriptome, and phenotypic variation data from 84 Japonica accessions to build a transcriptome-wide association study (TWAS) based regulatory network. All ECQ traits showed a large phenotypic variation and significant phenotypic correlations among the traits. TWAS analysis identified a total of 285 transcripts significantly associated with six ECQ traits. Genome-wide mapping of ECQ-associated transcripts revealed 66,905 quantitative expression traits (eQTLs), including 21,747 local eQTLs, and 45,158 trans-eQTLs, regulating the expression of 43 genes. The starch synthesis-related genes (SSRGs), starch synthase IV-1 (SSIV-1), starch branching enzyme 1 (SBE1), granule-bound starch synthase 2 (GBSS2), and ADP-glucose pyrophosphorylase small subunit 2a (OsAGPS2a) were found to have eQTLs regulating the expression of ECQ associated transcripts. Further, in co-expression analysis, 130 genes produced at least one network with 22 master regulators. In addition, we developed CRISPR/Cas9-edited glbl mutant lines that confirmed the role of alpha-globulin (glbl) in starch synthesis to validate the co-expression analysis. This study provided novel insights into the genetic regulation of ECQ traits, and transcripts associated with these traits were discovered that could be used in further rice breeding.

• 한국작물학회지
• /
• 제40권6호
• /
• pp.684-696
• /
• 1995

화청벼에서 유기시킨 심백경유 및 유전자적 웅성불임 돌연변이계통에 있어서 두 특성간의 상호관련성을 검토하였고, 종실의 몇가지 이화학적 특성을 밝혔다. 돌연변이계통의 생육형질과 불임의 안정성을 조사하였고 웅성불임화시 기를 추정하였다. 이들을 토대로 웅성불임종자의 조기 외관 식별에 의한 새로운 일대잡종품종 육성체계를 구상하였고 자연교잡율도 검토하였다. 그 결과는 다음과 같이 요약된다. 1. 심백 및 유전자적 웅성불임 돌연변이는 다면발현 효과를 가진 단순열성유전자에 의해 지배되었다. 즉 이 돌연변이계통이 교잡된 분리집단에서 심백종자는 곧 웅성불임종자임을 확인하였다. 2. 심백종자는 외형과 크기는 정상종자와 동일하였으나 배유 중앙부위의 전분결정조직이 성기고 전분입자 모양도 원형~타원형 이었다. 따라서 1,000립중, 절대밀도, 경도 등이 정상종자에 비해 유의하게 낮아졌다. 3. 심백종자의 단백질함량과 알칼리 붕괴도는 정상종자와 동일하였으나 아밀로스함량이 유의하게 낮아졌고, 호응집성에서는 상당히 harder gel 특성을 보였다. 4. 웅성불임식물체는 정상식물체에 비해 초장 및 간장이 현저히 단축되었고 이삭추출이 불량하였으며 주당수수가 유의하게 적었다. 5. 화분발육단계 중 웅성불임화시기는 감수분열기 이전인 것으로 추정되었고, 이 웅성불임은 온도나 일장에 관계없이 항상안정적이었다. 6. 이 돌연변이체를 이용하여 일대잡종을 육성하는 체계를 구상하였고, 그 효율을 세포질적-유전자적 웅성불임(CGMS)이나 환경감응 유전적 웅성불임(EGMS) 등을 이용하는 체계와 비교하였다. 7. 분리집단에서 정조상태로 웅성불임증자를 선별시 비중선 단독으로는 비중 1.14~l.16 g/cm 에서 순도 85~90% 웅성불임종자의 순도로 웅성불임종자를 선별할 수 있었는데, 10~15%의 흔입된 정상종자는 파종 후 유묘 또는 일대잡종생산포에서 생육상태 판정으로 용이하게 제거할 수 있을 것으로 판단되었다. 8. 웅성불임계통의 자연교잡율은 수분조작처리구(GA$_3$ 처리+지엽절단+rope 사용 화분털기)에서 화분친 2열, 웅성불임 1열 재식시 17.3%로 가장 높았다.

• 한국미생물·생명공학회지
• /
• 제23권6호
• /
• pp.647-651
• /
• 1995

A tylosin-hyperproductive mutant of S. fradiae MNU20 was isolated among 3500 strains obtaincd from either MNNG- or UV-treated Streptomyces fradiae NRRL2702. The composition of optimal medium for tylosin production was formulated as followed as: 4 g soluble starch, 1 g glucose, 1 g corn steep liquor, 7.5 ml soy bean oil, 0.2 g KH$_{2}$PO$_{4}$, 1 g Na$_{2}$S$_{2}$O$_{3}$$\cdot $5H$_{2}$O, 2 g CaCO$_{3}$, 2 g NaCl, 0.001 g CoCl$_{2}$$\cdot $6H$_{2}$O in 1 liter of distilled water. With the optimal medium, S. fradiae MNU20 was able to produce 159 mg tylosin (g biomass)$^{-1}$, indicating that tylosin productivity of Streptomyces fradiae NRRL2702 was increased 14 times higher by mutation. When the effect of valine, succinate, and natural zeolite on tylosin production was investigated by using the optimal medium, these substances essentially enhanced tylosin production and their addition time during culture period appeared to be critical for the increase of tylosin production.

• 미생물학회지
• /
• 제17권3호
• /
• pp.152-159
• /
• 1979

Using Micromonospora strain, gentamicin was produced by fermentation. The increase in gentamicin productivity was studied by strain improvement and systematic optimization of fermentation process variables. The productivity of parent strain of M.purpurea (ATCC15835) was improved by selection of superior mutant after U.V. irradiation and induction of genetamicin resistance. Potato starch and soy bean meal were the best carbon and nitrogen sources for gentamicin fermentation, respectively. The optimum stimulating concentration of Co ion for gentamicin production was 0.006g $CoCl_2$ per liter of broth. Oxygen ws found to be an important factor for gentamicin yield. The optimum pH for the cell growth and gentamicin production were 7.2 and 6.8 respectively. By controlling the pH, oxygen, and other conditions found in this study at the optimal conditions for cell growth and gentamicin production, the total productivity of gentamicin was increased significantly.

• 미생물학회지
• /
• 제15권2호
• /
• pp.63-76
• /
• 1977

Irradiation with high doses of gamma rays induced the reduction of mycelial weight and anaylase activity, and increased relative amylase activity in surface cultures. Biphase in growth curves was shown in aeration-agitation cultures but the behavior of the first phase of growth could be eliminated by replacing the amylasehydrolysed starch substrates, so that enzyme production was shortened ca. 40 hours and relative amylase activity was increased about 3 times higher before onset of autolysis. In the effect of gibberellin on amylase production, the positive stimulation was appeared to only surface culturs of the liquid medium and the negative effect to shake-cultures in a mutant. Trials of various continuous culture were resulted not only the approalch to the value of amylase activity in surface cultures of liquid medium, but also higher productivity than in batch cultures. The culture-degeneration was observed in two-stage continuous culture, but did not appear in continuous elevation culture.

• 한국미생물·생명공학회지
• /
• 제29권4호
• /
• pp.212-220
• /
• 2001

S. cerevisiae HBC52와 S, diataticus K114 의 rare mating 에 의해 개발된 HCS 균주들은 크기가 약 $13\mu\textrm{m}$ karyotype 분석결과 K114 균주에만 있는 약 1150kb 분자량을 가지는 염색체 band를 유지하였으며 전분을 분해하여 halo 를 형성하였다. Glucoamylase 활성은 약 2.7~3.4 unti/ml 를 가진 균주임이 밝혀졌으며 당 발효실험과 응집성 실험을 수행한 결과 HBC52 균주와 유사한 당 발효특성을 보이고 응집성 특성도 약응집성의 floculation type으로 비슷하였다. 그리고 HCS 균주의 포자형성과 피막형성 유무 실험에서는 양조효모인 HBC52 균주와 같이 포자가 형성되지 않았으며, 피막도 형성되지않았다. 균주들의 최종당도 실험은 HBC52균주가 약 68%의 발효수준을 나타냈고, HCS 균주들은 이 보다 높은 76~78%의 수준을 보였따. 즉 HBC52 균주가 최종당도($ 2.00^{\circ}$P)를 보인 반면 HCS 균주들은 ($0.7~0.93^{\circ}$P)를 보이는 결괄르 나타내어 맥주양조에서 low carbohydrate beer를 생산할 수있음이 확인되었다.

• 생명과학회지
• /
• 제32권9호
• /
• pp.698-705
• /
• 2022

우리나라의 쌀 소비량은 지속적으로 감소하고 있으며, 쌀 재고량을 감소시키는 방안이 끊임없이 제안되고있다. 쌀 소비량을 늘려 재고되는 양을 감소시키기 위해서는 단순히 밥으로 이용되는 것 이외에 새로운 쌀 가공 산업이 발전되어야 한다. 또한 최근 우리나라 국민들의 식생활이 다양해지고 있으며, 빵과 면의 소비가 증가하고 있다. 따라서 쌀의 용도를 다양화하기 위해 쌀가루 전용 품종을 육성하였다. 쌀 가루 가공에 적합한 계통을 육성하기 위해 일품을 조직배양 하여 돌연변이 집단을 구축하였다. 돌연변이 집단은 포장에서 주요 농업 형질에 대해서 조사 되었고, 수확 후에는 낟알 특성과 배유의 특성이 조사 되었다. 이들 계통 중 모품종인 일품과 농업형질이 비슷하고 품질이 우수한 29111 계통이 선발 되었다. 또한 식미를 결정하는 이화학적 특성이 일품과 유사하거나 향상 되었다. 하지만 29111는 일품과 달리 전분구조는 균일하지 않고 대형 전분립과 수형전분립이 골고루 분포되어 있어 분상질 배유의 특성을 가진다. 따라서 29111은 가공에 적합하면서 농업형질과 식미가 우수한 계통으로 육성되었다. 쌀 용도를 다양화하여 부가가치를 향상 시킬 수 있다. 또한 식미를 향상 시켰으며 생산자와 소비자 모두가 만족 할 수 있는 반찹쌀용과 분상질 미립 특성을 가진 품종 육성 방법을 제시하였다.

• Journal of Animal Science and Technology
• /
• 제51권6호
• /
• pp.527-536
• /
• 2009

A potent protein degrading bacterium was isolated from soil samples of different environments. Polyphasic taxonomic studies and phylogenetic 16S rRNA sequence analyses led to identify the isolate IB No. 11 as a strain of Bacillus subtilis. The isolated strain was recognized to produce protease constitutively, and the maximum production (1.64 units/ml) was attained in a shake flask culture when the isolate was grown at $40^{\circ}C$, for 32 h in basal medium supplemented with starch (0.25%) and gelatin (1.25%) as sole carbon and nitrogen source, respectively. The optimum pH and temperature for the protease activity were determined to be pH 7.0 and $50^{\circ}C$, respectively. $Ca^{2+}$ and $Mn^{2+}$ enhanced remarkably the protease activity but neither showed positive effect on the protease's thermal stability. In addition, it was observed that the protease was fairly stable in the pH range of 6.5-8.0 and at temperatures below $50^{\circ}C$, and it could be a good candidate for an animal feed additive. The inhibition profile of the protease by various inhibitors indicated that the enzyme is a member of serine-proteases. A combination of UV irradiation and NTG mutagenesis allowed to develop a protease hyper-producing mutant strain coded as IB No. 11-4. This mutant strain produced approximately 3.23-fold higher protease activity (6.74 units/mg) than the parent strain IB No. 11 when grown at $40^{\circ}C$ for 32h in the production medium. The protease production profile of the selected mutants was also confirmed by the zymography analysis.