• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1996년도 춘계학술대회
• /
• pp.186-186
• /
• 1996

Streptococcus pneumoniae (pneumococcus), the most common cause of bacterial pneumonia, has an ample polysaccharide(PS) capsule that is highly antigenic and is the source of PS vaccine. This investigation was undertaken to optimize the culture conditions for the production of capsular PS by type 1 pneumococcus. Among several culture media, brain heart infusion (BHI) and Casitone based media were found to support luxuriant growth of pneumococcus type 1 at the same level. Because BHI medium is rather expensive and more complex than the Casitone based media, the Casitone based media was used to study optimization of the culture condition. The phase of growth which accomodated maximum PS production was logarithmic phase. Concentrations of glucose greater than 0.2% did not enhance growth or PS production. Substitution of nitrogen sources with other resources or supplemention of various concentrations of metal ion (with the exception of calcium ion) had adverse effects on growth and PS production. On the other hand, low level aeration was beneficial for increased PS production. Addition of 3 mg/I concentration of methionine, phenylalanine, and threonine were found to enhance growth and PS production. The synergistic effect of all the favorable conditions observed in pneumococcal growth assays provided a two-fold cumulative increase in capsular PS production.

• 한국작물학회지
• /
• 제43권2호
• /
• pp.71-76
• /
• 1998

To define the relations between endogenous GA levels and growth and flowering in short-day plant sorghum, growth retardant BX-112 was applied to two sorghum genotypes, wild-type and phytochrome B mutant (phyB-1), which grows faster and flowers earlier than the wild-type. BX-112 and $GA_3$ were applied as a soil drench, and plant height, culm length, and date to floral initiation were investigated. Endogenous GAs contents were measured with GC-MS-SIM. BX-112 treatments inhibited shoot growth in both genotypes and drastically reduced $GA_1$ and $GA_8$ levels. With increasing BX-112 concentrations, $GA_1$ concentrations declined linearly, but caused the accumulation of intermediates from $GA_12$ to $GA_20$. This result implies that $GA_1$ is the major active endogenous GA in shoot elongation in a short day plant sorghum. The inhibition of plant growth in both of wild type and phyB-1 by BX-112 was very similar, while BX-112 effects on floral initiation in two types of plants differed significantly. Floral initiation of phyB-1 was not affected by BX-1l2, but that of wild-type was delayed as BX-1l2 concentration increased. Because BX-112 treatment causes accumulation of biosynthetic intermediates between synthetic pathway from $GA_12$ to $GA_20$ and because phyB-1 is altered in GA metabolism in this same region of the early C13-hydroxylation pathway, BX-112 may fail to block flowering of phyB-1.

• 대한수학회지
• /
• 제56권5호
• /
• pp.1419-1439
• /
• 2019

In this paper, we consider a class of noncooperative fourth-order elliptic systems involving nonlocal terms and critical growth in a bounded domain. With the help of Limit Index Theory due to Li [32] combined with the concentration compactness principle, we establish the existence of infinitely many solutions for the problem under the suitable conditions on the nonlinearity. Our results significantly complement and improve some recent results on the existence of solutions for fourth-order elliptic equations and Kirchhoff type problems with critical growth.

• 한국작물학회지
• /
• 제50권5호
• /
• pp.332-335
• /
• 2005

The three Korean wheat cultivars with different plant types; the erect, the middle and the creeping growth habit, were studied for their utilization to solar radiation, temperature changes on the furrow and to provide optimum planting space for producing the high yield in 2003. The average solar radiation rate was lowest for creeping type ($39.2\%$) and highest for erect type ($75.8\%$) The correlation coefficient between the coverage rate and the solar transmission rate was r = 0.8624 which was significant at $5\%$ level. The relative growth of the plant, tiller rate and leaf size was increased in the erect and the middle type at lower plant density, while no change on plant growth at creeping type regardless of plant density. The increase of leaf size in the lower plant density was due to longer flag and the first leaf than those of other plant types. The temperature on the furrow of growing plants was changed by the canopy. The changes in temperature pattern on the furrow according to plant types during winter season was different compared to the non plant ground. The temperature of the nonplant ground was the lowest due to solar reduction increasing the amount of cool air flowing in the furrow.

• Journal of Microbiology and Biotechnology
• /
• 제9권1호
• /
• pp.84-90
• /
• 1999

The growth of Bifidobacterium breve strain HP2 was completely inhibited by the addition of lactate higher than 4.0％ but not by the addition of acetate. Two kinds of lactate-tolerant mutants were isolated by the nitrosoguanidine treatment, enrichment on a liquid medium with 5％ lactate, and selection on agar plates with 5％ lactate. The mutants were not only able to grow in the presence of 5％ lactate but also improved in viable cell stability in the acidic pH range. In a pH-controlled fermentor, mutant N-1-5 grew at a rate slower than that of the wild type but its growth yield was higher. Notably, mutants were more halotolerant and more osmotolerant than the wild type and they were able to grow in the presence of 3％ NaCl or 25％ lactose at which the wild type entirely stopped the growth. The enzyme activities involved in the lactose metabolism in B. breve were measured to elucidate the biochemical basis for lactate tolerance. In the mutants, activities of several enzymes including phosphoglucomutase decreased compared to the wild-type, which may explain their lower growth rate. However, the activity of lactate dehydrogenase or its nature of inhibition by lactate was not altered.

• 수산해양교육연구
• /
• 제20권1호
• /
• pp.90-94
• /
• 2008

Growth and water quality in Japanese eel, Anguilla japonica ($6.0{\pm}0.9g$) fed extruded and paste type diets were compared for 8 weeks. Fish in the duplicate tanks were fed with one of three experimental diets: two different extruded pellet diets and one paste type diet. Six FRP tanks were used with stocking density of 3.6 kg per tank (3 m3). Restricted feeds (ca. 2% of body weight) were served twice daily. Weight gains were checked at the end of every two-week interval, and water qualities in terms of NH4-N and NO2-N were determined daily one hour after feeding in the morning. Water temperature, dissolved oxygen, and pH were constantly kept within the optimum range, while fifty percent of total water volume was changed daily. Eels fed the extruded pellet diets showed significantly better (P<0.05) growth performance than did eels fed the paste type diet. The amount of feed waste from the paste type diet was significantly greater than those from the extruded pellet diets (P<0.05). Ammonia (NH4-N) waste was significantly higher from the paste diet than from the extruded pellet diets (P<0.05). These results show that extruded pellet diets are better than the paste type diet for growth and water quality management in eel culture.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.429-432
• /
• 2000

생체 적합성, 생분해성, 항균성 등의 특징을 갖는 키토산 지지체는 type I -p collagen과 bFGF 또는 fibronectin을 함께 코팅함으로써 세포적합성을 향상시켜 섬유아세포의 증식과 ECM의 분비를 증가시킬 수 있으며, 인공피부를 위한 적합한 지지체로 사용될 수 있다고 사료된다.

• 미생물학회지
• /
• 제51권2호
• /
• pp.108-114
• /
• 2015

본 연구에서는 Streptomyces subrutilus P5의 생장과 세포내 외 철 함유 superoxide dismutase 활성을 비교 분석하여 철함유 superoxide dismutase의 분비 시점을 확인하고 분자 수준에서 이 효소의 분비에 관여하는 유전정보를 확인하고자 하였다. Streptomyces subrutilus P5의 균체 생장은 건체 중량을 측정하여 결정하였다. Glucose는 log phase에서 급격히 소모되어 24시간 후에 이르러 완전히 고갈되었다. 세포내의 철 함유 superoxide dismutase는 배양 후 3시간에 나타나며 세포외 철 함유 superoxide dismutase는 배양 후 7.5시간부터 나타난다. 따라서 superoxide dismutase는 용균에 의해서가 아니라 능동적인 분비기작에 의해서 세포 외로 분비된 것으로 추측할 수 있다. Streptomyces subrutilus P5의 sodF에는 signal peptide 유전정보가 존재하지 않았다. 그러나 sodF의 상류지역에서 다른 세균의 type III 분비단백질 유전자와 유사한 type III 분비상자가 발견되었다. Streptomyces 균주에서 type III 분비단백질이 존재할 가능성이 있음을 처음으로 제시하였다.

• Journal of Microbiology and Biotechnology
• /
• 제17권1호
• /
• pp.180-185
• /
• 2007

R-type pyocin is a bacteriophage tail-shaped bacteriocin produced by Pseudomonas aeruginosa, but its physiological roles are relatively unknown. Here we describe a role of R-type pyocin in the competitive growth advantages between P aeruginosa strains. Partial purification and gene disruption revealed that the major killing activity from the culture supernatant of PA14 is attributed to R-type pyocin, neither F-type nor S-type pyocins. These findings may provide insight into the forces governing P aeruginosa population dynamics to promote and maintain its biodiversity.

• Journal of Microbiology
• /
• 제33권2호
• /
• pp.146-148
• /
• 1995

Coprinus congregatus has a membrane-associated laccase which is not secreted into culture media. A mutant monokaryon obtained, by U. V. irradiation followed by protoplast generation and regeneration method, was successfully isolated. When the mutant was grown on a agar plate or in a liquid medium, it secreted laccase while the wild type did not under the same growth conditions. The laccase of the mutant was compared with that of wild type did not under the same growth conditions. The laccase of the mutant was compared with that of wild type of native PAGE analysis, and showed identical mobility.