• Archives of Pharmacal Research
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• 제13권1호
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• pp.33-37
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• 1990

The effects of pH values, temperature and some elements on the amylolytic activity and stability of the purified S. aureofacienc 77 amylase were studied in this investigation. The purified enzyme showed its maximum activity at pH 6 within 8 min incubation at $40^{\circ}C$. None of the tested 6 metals showed on stimulatory effect on the enzymatic activity, $Fe^{+++}$, $Cu^{++}$ and $Hg^{++}$ at high dose inhibited the enzyme activity to great extent as compared with $Zn^{++}$, $Mn^{++}$ and $Fe^{++}$ whih gave less effect in this respect. The enzyme liquor was found to be thermolabile, since it lost completely its activity after 4 days incubation under room temperature and showed maximum activity during this period as a result of additions of $Ca^{++}$and NaCl, Gradual reduction was however recorded until activity reached 30% after 60 days of incubation.

• 한국버섯학회지
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• 제1권1호
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• pp.34-43
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• 2003

느타리버섯 병재배 품종 다양화와 신품종 느타리버섯의 병재배기술 확립을 위해 춘추2호, 수한1호, 흑평의 배양온도별 적정 배양일수에 대한 연구 결과는 다음과 같다. 1. 춘추2호의 배양일수는 $23^{\circ}C$ 배양시 17일, $17^{\circ}C$에서 21일이었고 흑평은 $23^{\circ}C$와 $26^{\circ}C$ 배양시 17일, $17^{\circ}C$에서 22일이었으며, 수한은 22~23일로 배양온도간 비슷하였다. 2. 초발이 소요일수는 춘추2호와 흑평은 배양온도별로 4~5일 소요되었고 수한1호는 $17^{\circ}C$, $20^{\circ}C$, $23^{\circ}C$에서는 3일, $26^{\circ}C$에서는 5~6일이 소요되었다. 3. 자실체특성은 춘추2호의 경우 배양일수가 길수록 유효경수가 20~25개 정도로 많았고 수한1호는 배양일수가 짧을수록 유효경수가 많았다. 4. 춘추2호와 흑평 수량은 배양온도별로 배양기간이 길수록 높은 경향이었으나 수한1호는 배양기간이 길수록 감소하였다. 춘추2호와 흑평은 배양온도 $20{\sim}23^{\circ}C$에서 22~27일간, 수한1호는 $17{\sim}23^{\circ}C$에서 22~23일간 배양후 발이시켰을 때 수량이 가장 높았다.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.687-690
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• 1999

Bacillus stearothermophilus No. 236 isolated from the soil is a strong xylan degrader producing all the xylanolytic enzymes. However, the strain was discovered to be highly intractable to its transformation. In the present study, we have developed a reliable method for transformation of B. stearothermophilus No. 236 by a systematic examination of several factors which might have an influence on the efficiency of electrotransformation. Notably, we found that the most critical factor influencing the transformation efficiency (TE) was the incubation temperature after pulsing, with its optimum incubation of $37^{\circ}C.\; At\; 50^{\circ}C$, the optimum growth temperature of the B. stearothermophilus strain, the transformants could not be obtained at a recognizable level. The combination of field strength of 7.5 kV/cm along with pulse duration of 10 msec (resistance of $400{\Omega}\; and\; capacitance\; of\; 25{\mu}F$) was shown to be the best electrical parameters at the incubation temperature of $37^{\circ}$. A higher TE was obtained when the cells were harvested at an early-exponential phase. Twenty percent of PEG-8000 in a suspension buffer and an addition of 0.1% glycine in the growth medium resulted in about 4-fold and 3-fold increases in TE, respectively. We also found that the plasmid DNA which had been cycled through the host B. stearothermophilus cells enhanced TE by one order of magnitude higher. Under the presently described conditions, $2.5{\times}10^{5} transformants per ${\mu}g$ DNA was attained.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.529-532
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• 2001

Korean food waste, one of the abundantly available but environmentally problematic organic wastes in Korea, was utilized as solid-substrate by fungal strain Aspergillus niger ATcC 6275 for the production of enzymemixture containing amylase, cellulase and xylanase. The enzyme mixture can be used as high value-added animal feed. Solid-state fermentation method yielded a 84-fold enhancement in xylanase activity compared with submerged fermentation method. The effect of incubation period, incubation temperature, pH of medium, moisture content, inoculum size and enrichment of the medium with nitrogen and carbon sources were observed for optimal production of these enzymes The optimal amylase activity of 33.10 U/g, cellulase activity of 24.41 U/g, xylanase activity of 328.84 U/g were obtained at 8 days incubation with 50%(w/w) soy bean flake, with incubation temperature of $25^{\circ}C$, pH of 6.38, optimal moisture content of 55% and with inoculum size of $3.8{\times}10^6$spore/g. Enzyme activities were enhanced when ImM $CaSO_4$, 2% Malt extract and 2% galactose were added as mineral, nitrogen and carbon enrichment respectively.

• 한국재료학회지
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• 제12권5호
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• pp.363-368
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• 2002

we proposed the use of $Si_2H_ 6/H_2$ chemistry for selective silicon epitaxy growth by low-pressure chemical vapor deposition(LPCVD) in the temperature range $600~710^{\circ}C$ under an ultraclean environment. As a result of ultraclean processing, an incubation period of Si deposition only on $SiO_2$ was found, and low temperature epitaxy selective deposition on Si was achieved without addition of HCI. Total gas flow rate and deposition pressure were 16.6sccm and 3.5mtorr, respectively. In this condition, we selectively obtained high-quality epitaxial Si layers of the 350~1050$\AA$ thickness. In older to extend the selectivity, we kept high pressure $H_2$ environment without $Si_2H_6$ gas for few minutes after first incubation period and then we conformed the existence of second incubation period.

• Journal of Dairy Science and Biotechnology
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• 제41권2호
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• pp.45-56
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• 2023

This review serves two purposes: first, to promote the use of improved optimization techniques in response surface methodology (RSM); and second, to enhance the optimum conditions for the fermentation of probiotics. According to research in dairy science, Lactiplantibacillus plantarum K79 is a candidate probiotic that has beneficial health effects, such as lowering blood pressure. The optimum conditions for L. plantarumK79 to produce peptides with angiotensin-converting enzyme (ACE) inhibitory activity were proposed, through modeling each of ACE inhibitory activity and pH as a function of the four factors that are skim milk concentration (%), incubation temperature (℃), incubation time (hours), and starter added amount (%). To estimate optimum conditions, the researchers employed a desirability-based multi-response optimization approach, utilizing third-order models with a nonsignificant lack of fit. The estimated optimum fermentation conditions for L. plantarum K79 were as follows: a skim milk concentration of 10.76%, an incubation temperature of 36.9℃, an incubation time of 23.76 hours, and a starter added amount of 0.098%. Under these conditions, the predicted ACE inhibitory activity was 91.047%, and the predicted pH was 4.6. These predicted values achieved the objectives of the multi-response optimization in this study.

• 한국식품과학회지
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• 제20권3호
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• pp.326-330
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• 1988

마이크로컴퓨터 코오지 배양시설을 제작하여 배양실내의 온도, 상대습도를 계측하고 코오지의 무게를 공정제어 대상으로 공정의 자동화를 시도하였다. 코오지 무게변화는 외팔보형 strain gauge 무게감응장치로 코오지 및 배양실의 온도는 백금저항선$(Pt,\;100\Omega)$ 센서로 계측하였다. 계측신호는 디지털화하여 MC6821 접속소자를 통해 마이크로컴퓨터로 입력되었다. 코오지 무게계측치를 공정의 제어대상으로 할 때 디지탈값(Y)과 코오지의 무게(W,g) 사이의 관계는 Y=0.310W+32.329(r=0.99989)이었다. 배양실내의 온도제어는 폐회로방식에 의하여 on/off로 이루어졌으며 습도제어는 계측된 건, 습구 온도값으로부터 계산된 습도값을 기준으로 살균수의 분무로 수행되었다.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.85-92
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• 1999

We examined the expression patterns of heat shock proteins in primary cultured hepatocytes from flounder (Paralichthys olivaceus) exposed to heat shock. The expression of hsp90, hsp70, hsp40, hsp30, and hsp27 was induced and major polypeptides were hsp70, hsp30 and hsp27. Northern blot analysis showed that expression of hsp70 was inhibited by transcriptional inhibitor actinomycin D, suggesting that expression of hsp70 gene is regulated at the transcriptional level. Prolonged exposure of cells to an elevated incubation temperature $(30^{\circ}C)$ induced the transient synthesis of hsp90, hsp70, hsp40, and hsp30 whereas maintenance of cells at a slightly higher incubation temperature $(32^{\circ}C)$ induced the continuous syntheses of these hsps. When cells were incubated at a higher temperatures $(35^{\circ}C\;or\;37^{\circ}C)$, the synthesis of hsps was almost similar to that of hsps in cells exposed to 32't except for the induction of hsp27 synthesis. These results that temperature and incubation time for optimum expression of each hsp during prolonged heat shock are different.

• Reproductive and Developmental Biology
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• 제30권1호
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• pp.71-74
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• 2006

Hypoosmotic swelling test (HOST) is used for evaluating the plasma membrane function and fertilizing ability in mammal spermatozoa. However, HOS solutions and experimental conditions have not been determined clearly for assessing canine spermatozoa. This study was conducted to examine the HOS solutions and assay conditions, including incubation time (30 to 120 min), storage temperature (4, 17 and $20^{\circ}C$), semen status (fresh and frozen). Maximum spermatozoal plasma membrane swelling was obtained in an 150 mOsm Na-citrate/Fructose solutions with an incubation time for 45 min. The storage temperature and semen status affected the percentage of HOS positive spermatozoa. The HOS test adapted to canine spermatozoa in this study was simple and highly consistent assay with good repeatability. The optimal condition of HOST in canine spermatozoa is an 150 mOsm Na-citrate/Fructose solutions with an incubation time for 45 min regardless of semen storage temperature and semen status.

• 한국작물학회지
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• 제45권2호
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• pp.103-107
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• 2000

The viviparity of 28 rice varieties was tested at 25 days after heading(DAH), 35DAH, and 45DAH in the laboratory and field condition for 12 days. The incubation temperature was 20/l$0^{\circ}C$ (day/night), 25/15$^{\circ}$C$ and 30/20$^{\circ}$C$ in the laboratory test, and under field water conditions in the field test. The biggest varietal difference of viviparity was found in the laboratory test when examined at 45DAH with the 6-day incubation under 25/15$^{\circ}$C$ . At this conditions the mean viviparous ratio was 32.1 % with the range of 53.9 and the variance of 259.5. In the field test, the significant varietal difference in the viviparity was also found in the lodging treatment at 45 DAH for 6 days. Correlation coefficient analysis between the field and laboratory tests was highly significant from 4 days after incubation at 45 DAH and after 6-day incubation at 35 DAH, and correlation coefficient was higher as incubation days in the laboratory and submerged days under field water became longer. Considering the correlation between the field and laboratory tests, varietal difference of viviparity and convenience of testing, the laboratory test at 45 DAH for 6-day incubation under 25/15$^{\circ}$C$ was the most efficient evaluation method for the viviparity of rice cultivar.