• Title/Summary/Keyword: jar

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Development of a Culture Medium for Growth and Sporulation of Bacillus polyfermenticus SCD (프로바이오틱 비스루트균의 아포생산을 위한 최적배지 개발)

  • Lee, Kwang-Ho;Park, Kyu-Yong;Kim, Seong-Mi;Kim, Won-Seok;Paik, Hyun-Dong
    • Korean Journal of Food Science and Technology
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    • v.34 no.2
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    • pp.263-268
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    • 2002
  • Bacillus polyfermenticus SCD, which is commonly called a 'Bisroot' strain, has been appropriately used for the treatment of long-term intestinal disorders, since the live strains, in the form of active endospores, can successfully reach the target intestine. Goal of this study was to develop an industrial medium for growth and sporulation of B. polyfermenticus SCD. From the results of effect of mixed carbon sources on growth and sporulation of B. polyfermenticus SCD, glucose 2% and starch 2% was particularly found to be the most effective for the maximum number of spore production, resulting in spore cells of $4.3{\times}10^9\;spores/mL$ with a sporulation yield of 91%. For the effect of nitrogen sources, the maximum spore cells of $5.7{\times}10^9\;spores/mL$ of B. polyfermenticus SCD with a sporulation yield of 97% was obtained when B. polyfermenticus SCD was cultivated in an optimum nitrogen source medium containing 5% soybean flour. A medium involving proper phosphate salt yielded the maximum number of a spore cells of $6.0{\times}10^9\;spores/mL$ with a sporulation yield of 95%. Finally, the efficacy of an industrial medium (KH5 medium) on growth and sporulation of B. polyfermenticus SCD was investigated in jar fermenter. The higher number of viable cells $(3.3{\times}10^{10}\;cells/mL)$ and spore cells $(3.0{\times}10^{10}\;spores/mL)$ were obtained in 5 L fermenter when compared with a 500 mL baffle flask cultivation. Thus, KH5 medium developed in this study shows promise as an industrial medium because of higher cells and sporulation yield.

Development of Saccharomyces cerevisiae Strains with High RNA Content (리보핵산을 다량으로 함유하는 Saccharomyces cerevisiae 균주의 개발)

  • Kim, Jae-Sik;Kim, Jin-Wook;Shim, Won;Min, Byoung-Cheol;Kim, Jung-Wan;Park, Kwan-Hwa;Pek, Un-Hua
    • Korean Journal of Food Science and Technology
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    • v.31 no.2
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    • pp.465-474
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    • 1999
  • RNase activity of Saccharomyces cerevisiae ATCC 7754 was investigated to obtain strains with high ribonucleic acid (RNA) content. The yeast strain contained two RNase activities; an acidic RNase with a optima of pH $3{\sim}4$ and an alkaline RNase with a optima pH 9. The acidic RNase activity was inhibited by $0.08\;M\;HgCl_{2}$ most drastically. The alkaline RNase activity was inhibited by 2.0 M NaCl or KCl, while enhanced by addition of $0.05\;M\;CaCl_{2},\;0.02\;M\;ZnSO_{4},\;or\;0.008\;M\;HgCl_{2}$. Various mutants of Saccharomyces cerevisiae ATCC 7754 were isolated by ethylmethane sulfonate (EMS) treatment or $\gamma$-ray/ultra violet irradiation. Among the mutants that were sensitive to high concentration of KCl which inhibits alkaline RNase, B24 was selected for high RNA content per culture volume. Growth characteristics of the mutant were comparable to those of the mother strain with optimum growth at pH $4.5{\sim}5.5$. The mutant accumulated higher content of RNA than the mother strain when glucose was used as the carbon source. However, both growth rate and total RNA content of the mutant were higher in molasses medium than in glucose medium. RNA content of the mutant increased rapidly during the early stage of growth, and then decreased gradually until the culture reached stationary phase by a fed-batch culture in a 5 L jar fermenter. Maximal cell harvest and the final RNA content using the mutant B24 were 69.6 g/L culture broth and 19.8 g/100 g of the dry cell while those using the mother strain were 68 g/L culture broth and 16.1 g/100 g of dry cell, respectively.

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Filtering Rate with Effect of Water Temperature and Size of Two Farming Ascidians Styela clava and S. plicata, and a Farming Mussel Mytilus edulis (수온과 개체크기에 따른 양식산 미더덕, 흰멍게, 진주담치의 여수율)

  • KIM Yong Sool;Moon Tae Seok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.2
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    • pp.272-277
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    • 1998
  • Filtering rates of two farming ascidians Styela clava and S. plicata, and of a farming mussel Mytilus edulis were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates were carried out in a closed system with experimental animals being decreased indicate dyes neutral red. Optical density (OD) of 440 nm in path length 22 mm cell used as the indication of food particles absorption was appeared directly in proportion with the concentration of neutral red dyes. The filtering rate F is calculated by Kim's equation $F\;=\;V(1-e^{-z})$, where V is the water volume ($\ell$) in the experimental jar, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed as In $C_t\;=\;In\;C_{o}-Z{\cdot}t$, in this formula $C_t$ is OD at the time t. Filtering rate of S. clava increased as exponential function with increasing temperature while not over critical limit, and the critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. In case of S. plicata, the critical temperature was to be below $13^{\circ}C$, and through the temperature range $15\~25^{\circ}C$ appeared a little difference in level even though with significant. M. edulis was not appear any significant effects by water temperature less than $29^{\circ}C$. The model formula derived from the results is as below, where F is filtering rate (${\ell}/hr/animal$), T is water temperature ($^{\circ}C$), and DW is dry meat weight (g) of experimental animal. $$S.\;Clava;\;F\;=\;e xp\;(0.119\;T-4.540)\;(DW)^{0.6745},\;T<29^{\circ}C$$) $$S.\;plicata;\;F\;=\;e xp\;(A_t)\;(DW)^{0.5675},\;(13^{\circ}C $$[A_t =-8.56+0.6805\;T-0.0153\;T^2]$$ $$M.\;edulis;\;F\;=\;0.3844\;(DW)^{0.4952},\;<29^{\circ}C$$)

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Removal of Red Tide Organisms -1. flocculation of Red Tide Organisms by Using IOSP- (적조생물의 구제 -1. IOSP에 의한 적조생물의 응집제거-)

  • KIM Sung-Jae;CHO Kyu-Dae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.448-454
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    • 2000
  • This study was to examine the physicochemical characteristics of coagulation reaction between ignited oyster shell powder (IOSP) and red tide organisms (RTO), and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea,IOSP was made from oyster shell and its physicochemical characteristics were examined for particle size distribution, surface characteristic by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various c(Incentrations of IOSP, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number, IOSP showed positive zeta potentials of $11.1{\~}50.1\;mV\;at\;pH\;6.2{\~}12.7$, A positive zeta potential of IOSP slowly decreased with decreasing pNa 4,0 to 2,0. When pNa reached zero, the zeta potential approached zero, When a pMg value was decreased, the positive zeta potential of IOSP increased until pMg 3.0 and decreased below pMg 3.0. IOSP showed 4.8 mV of positive zeta potential while RTO showed -9.2 mV of negative zeta potential in sea water. A positive-negative EDL (electrical double-layer) interaction occurred between $Mg(OH)_2$ adsorption layer of IOSP and RTO in sea water so that EDL attractive force always worked between them. Hence, their coagulation reaction occurred at primary minimum on which an extreme attractive force acted because of charge neutralization by $Mg(OH)_2$ adsorption layer of IOSP. As a result, the coagulation reaction was rapidly processed and was irreversible according to DLVO (Deriaguin-Landau-Verwey-Overbeek) theory. Removal rates of RTO were exponentially increased with increasing both IOSP concentration and G-value. The removal rates were steeply increased until 50 mg/l of IOSP and reached $100{\%}\;at\;400\;mg/l$ of IOSP. Removal rates of RTO were $70.5,\;70.5,\;81.7,\;85.3{\%}$ for G-values of $1,\;6,\;29,\;139\;sec^(-1)$at IOSP 100 mg/l, respectively. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction.

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Optimization of Culture Conditions for Xylitol Production by A Mutant of Candida parapsilosis (Candida parapsilosis 돌연변이주에 의한 Xylitol 생산조건의 최적화)

  • Oh, Deok-Kun;Kim, Sang-Yong;Kim, Jung-Hoe
    • Applied Biological Chemistry
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    • v.39 no.3
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    • pp.172-176
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    • 1996
  • Effect of culture conditions such as pH, temperature, agitation speed and oxygen transfer rate on xylitol production from xylose by Candide parapsilosis ATCC 21019 mutant was investigated in a jar fermentor. The initial concentration of xylosr was fixed at 50 g/l in this experiment. When pH was increased, cell growth and xylose consumption rate were increased, but maximum xylitol production was shown in the range of pH 4.5 and 5.5 with a yield of 0.68 g/g-xylose. The optimal temperature for xylitol production was determined to be $30^{\circ}C$. Considering the importance of dissolved oxygen tension, for xylitol production, the effect of oxygen transfer rate coefficient $(k_La)$ on fermentation parameters was carefully evaluated in the range of $20{\sim}85\;hr{-1}\;of\;k_La$ (corresponding to $100{\sim}300$rpm of agitation speed). The xylitol production was maximized at $30\;hr^{-1}\;of\;k_La$(150 rpm). A higher oxygen transfer rate supported better cell growth with lower xylitol yield. It was determined that maximum xylitol concentration, xylitol yield and productivity was 35.8 g/l, 71.6% and $0.58\;g/l{\sim}hr^{-1}$, respectively, at $30\;hr^{-1}\;of\;k_La$ In order to further increase xylitol productivity, ferementation using the concentrated biomass(20 g/l) was carried out at the conditions of pH 4.5, $30^{\circ}C$ and $30\;hr\;1$ of oxygen transfer rate. The final xylitol concentration of 40 g/l was obtained at 18 hours of culture time. From this result, it was calculated that xylitol yield was 80ft on the basis of xylose consumption and volumetric productivity was $2.22\;g/l{\sim}hr$ which was increased by $3{\sim}4$ fold compared with $0.5{\sim}0.7\;g/l-hr$ obtained in a normal fermentation condition.

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Preliminary Research on the Effect of Cosmetic Containing Ginseng Extract on Quality of Life of Healthy Women Based on Skindex-16 (인삼 추출물 함유 한방화장품이 건강한 성인 여성의 삶의 질에 미치는 영향에 관한 예비 연구; Skindex-16을 중심으로)

  • Cho, Ga Young;Park, Hyo Min;Kwon, Lee Kyung;Cho, Sung A;Kang, Byung Young;Kim, Yoon Bum
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.41 no.4
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    • pp.333-340
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    • 2015
  • This study is designed to analyze the effect of skincare using cosmetic containing ginseng extract, on improving quality of life (QOL) of healthy women, with blind testing. QOL is a concept that represents how one's disease or health condition can physically, psychologically, and socially influence his or her daily life. The study was conducted to assess the effect of a ginseng cosmetic preparation on quality of life (QOL) using the Skindex-16 score, stratified by blind versus non-blinded option. 45 healthy women aged between 30 and 49 years with no skin disease were recruited for this study. Volunteers were divided into two groups. Group A (n = 22) received anti-aging cream with ginseng extract in the original packaging, which included the brand name and logo. Group B (n = 23) received the same cream in a plain white jar without any package decoration or logo. Both groups used the cream for 8 weeks. For the skin-related QOL assessment, Skindex-16 was used at baseline, forth, and eighth week. All volunteers except two dropouts in Group A completed the dermatology-specific QOL measure, Skindex-16, at baseline, after 4 weeks, and after 8 weeks of treatment with the provided samples. As a result, the mean score of 43 participants at baseline was $22.70{\pm}4.82$. There was a significant difference between the baseline score and the score after 8 weeks in both groups: The scores changed from $23.30{\pm}5.14$ to $20.20{\pm}4.83$ in Group A, from $22.17{\pm}4.58$ to $20.52{\pm}3.60$ in Group B. The "Symptom" subscale of Skindex-16 improved after 4 weeks and the "Emotion" subscale improved after 8 weeks in Group A. The "Function" subscale did not show improvement in either groups. Both groups showed no interaction effect between follow up time and groups in Skindex-16 and subscale. This research opens up the possibility of skincare using ginseng cream having a positive effect on QOL in healthy women. Moreover, one can predict that skincare ritual itself may have greater impact on the improvement of QOL, compared to the product packaging.

Comparative Study on the Dancheong(丹靑) of Buddhist Temples in Jeolla Region focused on the Dancheong of the main building of Mihwangsa Buddhist Temple at Haenam(海南) (전라도지역 사찰단청(寺刹丹靑)의 비교 연구 해남 미황사(美黃寺) 대웅전(大雄殿) 단청을 중심으로)

  • Lee, Su Yee
    • Korean Journal of Heritage: History & Science
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    • v.42 no.4
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    • pp.152-171
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    • 2009
  • The Dancheong(丹靑) of the main building of Mihwangsa Buddhist Temple(美黃寺) in Haenam(海南) is the leading work of the Jeolla Dancheong style, which was created in the 18th century and has been passed down to the early modern days, and boasts its excellence and originality. On the outside, one can only see the traces of the Dancheong due to the colors that fell off and deteriorated severely. On the inside, however, the general Dancheong pattern is accompanied by the painting of 1,000 Buddhas(千佛圖), which is hardly found in other Buddhist temples, and the Arahan painting, which is truly magnificent in technique and can pass as an independent painting. The Dancheong also has unique methodological characteristics that can't be found in other Dancheong works such as the painting and attaching technique. The Dancheong inside is estimated to have been created in 1754 considering the records of "Dalmasan Mihwangsasa Daebeopdang Jungsusangryangmun(達摩山美黃寺大法堂重修上樑文)", the calligraphical writings of "Mudeungsanindanhwakya(無等山人丹?也)"and "Geonryungshipgu(乾隆十九)" left in the Jungryang, and the style characteristics reflected in the Dancheong patterns and the painting of 1,000 Buddhas. The fact that there are no traces of re-Dancheong also supports the estimation that the Dancheong was created in the absolute age of 1754. The absolute age will be the reference of deciding the chronological years of Dancheong patterns and be helpful in examining the characteristics and changes by the periods. There were certain style characteristics in Dancheong by the periods and regions. The Dancheong of Jeolla region also had its own style, which includes the tendency of finishing with two- or three-fold green belts without giving meokdanggi to the meoricho and the huge jar decoration of huigol. Treating the baetbadak of all materials, whether it's Geumdancheong or morodancheong, with lines of certain thickness and colors is another style of Jeolla Dancheong from the 18th to the 20th century. The Dancheong of the Geukrakbojeon(極樂寶殿) of Cheoneunsa Buddhist Temple and Daewoongbojeon(大雄寶殿) of Naesosa Buddhist Temple in Jeolla is especially noteworthy in that it bears similar patterns and techniques to that of the main building of Mihwangsa Buddhist Temple in addition to the characteristics mentioned above. The Dancheong of Mihwangsa Buddhist Temple must have exerted so great influences on that of the two temples that it's called "the style of Mihwangsa Buddhist Temple."When adopting a broader point of view, it can be classified as one of the Dancheong styles of Jeolla. The common icons and techniques found in the Dancheong of Mihwangsa, Cheoneunsa, and Naesosa Buddhist Temple provide some clues about the influential relationships among painters of the days. They may have been created by the painters of the same school or the painters affected by those who created the Dancheong of Mihwangsa Buddhist Temple.

A Study on the "Holing-Bowl(받침그릇, 承盤) for the Jung-Byoung(정병, 淨甁)" or The Sacred Water-pot (정병 받침그릇(淨甁 承盤) 살핌 -고려불화(佛畵)-수월관음그림(水月觀音圖)으로 -)

  • Ghang, soon-hyoung
    • Korean Journal of Heritage: History & Science
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    • v.34
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    • pp.124-136
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    • 2001
  • Among many different types of wares, we have amazing Sacred Water-pot(따르개, 注子) from Goryo-period(고리, 高麗, 918-1392). The stylistic peculiarity of Jung-Byoung(정병, 淨甁) is described in "Goryo-Dhogyoung, 고리도경, 高麗圖經", the classical design canon. It is said, "A sharpened mouth with narrow and prolonged neck is attached upon the broad mouth with thicker and even longer neck of the pot whose body intimates to the shape of melon." One could find this Jung-Byoung similar to the Indian drinking water jar, Kundika, which has been. even today, an everyday article in houses as well as in temples. In the early Buddhist cult, the object had been adopted as personal belonging of the Bodhisattvas(보살, 菩薩), especially of the Bodhisattva Avalokitesvara(관세음보살,觀世音菩薩). In short, the purifying character of water is met by the sacred ware to deliver the refreshing Sweet-Water(Holy-Water, 깨맑물, 단물, 단이슬물, 정수, 감로, 감로수, 성수, 淨水, 甘露, 甘露水, 聖水): For the holy purpose of fulfilling the thirst of people, of symbolozing the virtuous dharma. Thus, Ggamslkh-Byoung(깨맑병,淨水), the literal Korean name, denotes purifying and clarifying and clarifying water-pot to us. Among many other Asian countries, India, China, Korea, and Japan have a profound cult of the sacred water-pot(Ggamalkh-Byoung, Jung-Byoung, 깨맑병, 정병, 정수병, 감로병, 감로수병, 淨甁, 淨水甁, 甘露甁, 甘露水甁). Therefore, this charming holy object drew much attention not only from master artisans to shape and deliver them to people but also from painters and sculptors for their endowment of the sacred images dedicated to Buddha(부처,佛,佛陀). In China, the sacred water pot emerged in the period of Tang(당, 唐, 618~907)-Period and underwent much sophistication later on, I. e., from earthenware, ceramic-porcelain, bronze, and silver. However, the following represents a challenge to the well-known Goryo-Thangka(고리불화, 高麗佛畵) Painting of Bodhisattva Avalokitesvara to our speculation on the Sacred Water-pot(정병, 淨甁). The image suggests, when examined closely, that the Sacred Water-pot has been accompanied by, or placed in, a transparent glasswere(유리그릇) or crystalbowl(수정그릇)! We have no other physical proof of the existence of such a Holding-Bowl(받침그릇, 承盤), except for in this particular painting. This Holding-Bowl would have not been a mere elaboration on the practicality of controling the drips from the mouth of the pot. As in the chapter on Tang-ho(탕호, 湯壺), or thermal bowl, in the "Goryo-Dhogyoung" it advises readers that this style of bowl is to be filled with hot water, and thus function as a preserver of heat in the water inside the pot. As an offering to the Buddha, the Sacred Water-pot could have been used for serving him hot tea. Hence the sacred bottle is to contain the refreshing water, the water transcends to nectar, and the nectar is prepared as a nectar tea to offer the Buddha. For both the Holding-Bowl of Ggamalkh-Byoung(Jung-Byoung)and the Celestial-Robe(날개옷, 天衣) of the Bodhisattva Avalokitesvara, whose specified character is the Water-Moon(수월, 水月) in this particular Thangka(불화, 佛畵) painting, the transparency is essential. This is to refer to the purity and the lucid clarity of Bodhisattva Avalokitesvara and at a deeper level, to refer to the world of Buddhas-the Tushita(Paradise, Heaven, Eden, 극락, 불세계, 極樂, 佛世界). Howerver, without the discovery of an actual Holding-Bowl, accompanied by a Sacred Water-pot, such speculation will necessarily remain hypothetical. Nevertheless, there is an abundance of evidence of our ancient craftsmanship in jade and ctystal, dating back to the Bronze Age(1000~2B.C.) in Korea. By the time of the Three Kingdom-Period(삼국시대, 三國時代, 57B.C.~935A.D.), and especially the Silla(신라, 新羅, 57B.C.~935A.D.)-Empire, the jade and crystal ornamentation had become very intricate indeed. By the Goryo-Period(918~1392) and Chosun-Period(조선, 朝鮮,1392~1910),crystal-ware and jade art were popular in houses and Buddhist temples, whose master artsanship was heightened in the numerous Sarira-Cases(사리그릇, 舍利器), containing relics and placed inside Stupas(탑, 투, 搭)! Therefore, discovering a tiny part of the crystal or jade Holding-Bowl for the Sacred Water-pot and casting full light on this subject, would not be totally impossible. Lastly the present article shares the tiny hope for a sudden emergence of such a Holding-Bowl.

Hanseong Period of Baekje and Mahan (한성시대(漢城時代)의 백제(百濟)와 마한(馬韓))

  • Choi, Mong-Lyong
    • Korean Journal of Heritage: History & Science
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    • v.36
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    • pp.5-38
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    • 2003
  • The history of Baekje Kingdom, one of the Three kingdoms, is divided into three periods to the change of sociopolitical center, including its capital as follows: Hanseong Period (18 BC ~ AD 475), Ungjin Period (AD 475~538), and Sabi Period (AD 538~660). Though the Hanseong Period of Baekje Kingdom covers more than two thirds of the whole history of Baekje Kingdom (493 years), history and archaeological culture of the Hanseong Period is still unclear and even ambiguous comparing to the Ungjin and Sabi periods. Most of all, it is because of quite limited historical records and archaeological data available. In addition, negative attitude of the Korean academic circles to the early records of Samguksaki(三國史記) has been a critical obstacle to the study of early history of the Three kingdoms, including the Hanseong Period of Baekje kingdom. Author, who has attempted to combine historical records and archaeological data in order to reconstruct the history and archaeological culture of the early Baekje, specifically the Hanseong Period, has held positive attitude to the early records of the Samguksaki as far as possible. He(Author) came to realize that comprehensive understanding of Mahan (馬韓) society, one of the Three Han (三韓) Society was more than essential in the study of Baekje. According to historical records and archaeological data, Mahan Society represented by Mojiguk(目支國) ruled by King Jin(辰王) has been located in the middle and/or southwestern parts of the Korean peninsula from the 3rd~2nd century BC through the end of the 5th century or early 6th century AD. Mahan already occupied central portion of the Korean Peninsula, including the Han River Valley when King Onjo(溫祖王) first set up the capital of Baekje Kingdom at Wiryeseong (慰 禮城) considered to be modern Jungrang~Songpa-gu area of Han River Valley. From the beginning of the Baekje history, there had been quite close interrelationships between Baekje and Mahan, and the interrelationships had lasted for around 500 years. In other words, it is impossible to attempt to understand and study Hanseong period of Baekje, without considering the historical and archaeological identity of Mahan. According to the Samguksaki, Baekje moved its capital three times during the Hanseong Period (18 BC ~ AD 475) within the Han River Valley as follows: Wiryeseong at Jungrang-gu area of the Han River (河北慰禮城, 18 ~ 5 BC), Wiryeseong at Songpa-gu area of the Han River(河南慰禮城, 5 BC ~ AD 371), Hansan at Iseongsan fortress site(Historical site No. 422, 漢山, AD 371~391), and Hanseong at Chungung-dong of Hanam city(漢城, AD 391~475). Before 1990s, archaeological data of the Hanseong Period was quite limited, and archaeological culture of Mahan was not well defined. Only a few burial and fortress sites were reported to be archaeological remains of the early Baekje, and a few settlement and jar burial sites were assumed to be those of Mahan without clear definition of the Mahan Culture. Since 1990s, fortunately, a number of new archaeological sites of Hanseong Baekje and Mahan have been reported and investigated. Thanks to the new discoveries, there has been significant progress in the study of early Baekje and Mahan. In particular, a number of excavations of Pungnap-dong Fortress site(Historical site NO. 11, 1996~2003), considered to be the Wiryeseong at south of the Han River, the second capital of the Hanseong Baekje, provided critical archaeological evidence in the study of Hanseong Period of Baekje. Since the end of the 1990s, a number of sites have been reported in Gyeonggi, Chungcheong, and Jeolla provinces, as well. From these sites, archaeological features and artifacts representing distinctive cultural tradition of Mahan have been identified such as unstamped fortresses, pit houses cut into the rock, houses with lifted floor(掘立柱 건물), and potteries decorated with toothed wheel and bird's footprint designs. These cultural traditions reflected in the archaeological remains played a critical role to define and understand archaeological identity of the Mahan society. Moreover, archaeological data from these new sites reported in the middle and southwestern parts of the Korean Peninsular made it possible to postulate a hypothesis that the history of Mahan could be divided into three periods to the change of its sociopolitical center in relation with the Baekje Kingdom's political Situation as follows: Cheonan (天安) Period, Iksan(益山) Period, and Naju(羅州) Period. The change of Mahan's sociopolitical center is closely related to the sociopolitical expansion of the Hanseong Baekje.

Production of Medium-chain-length Poly (3-hydroxyalkanoates) by Pseudomonas sp. EML8 from Waste Frying Oil (Pseudomonas sp. EML8 균주를 이용한 폐식용류로부터 medium-chain-length poly(3-hydroxyalkanoates) 생합성)

  • Kim, Tae-Gyeong;Kim, Jong-Sik;Chung, Chung-Wook
    • Journal of Life Science
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    • v.31 no.1
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    • pp.90-99
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    • 2021
  • In this study, to reduce the production cost of poly(3-hydroxyalkanoates) (PHA), optimal cell growth and PHA biosynthesis conditions of the isolated strain Pseudomonas sp. EML8 were established using waste frying oil (WFO) as the cheap carbon source. Gas chromatography (GC) and GC mass spectrometry analysis of the medium-chain-length PHA (mcl-PHAWFO) obtained by Pseudomonas sp. EML8 of WFO indicated that it was composed of 7.28 mol% 3-hydrxoyhexanoate, 39.04 mol% 3-hydroxyoctanoate, 37.11 mol% 3-hydroxydecanoate, and 16.58 mol% 3-hydroxvdodecanoate monomers. When Pseudomonas sp. EML8 were culture in flask, the maximum dry cell weight (DCW) and the mcl-PHAWFO yield (g/l) were showed under WFO (20 g/l), (NH4)2SO4 (0.5 g/l), pH 7, and 25℃ culture conditions. Based on this, the highest DCW, mcl-PHAWFO content, and mcl-PHAWFO yield from 3-l-jar fermentation was obtained after 48 hr. Similar results were obtained using 20 g/l of fresh frying oil (FFO) as a control carbon source. In this case, the DCW, the mcl-PHAFFO content, and the mcl-PHAFFO yields were 2.7 g/l, 62 wt%, and 1.6 g/l, respectively. Gel permeation chromatography analysis confirmed the average molecular weight of the mcl-PHAWFO and mcl-PHAFFO to be between 165-175 kDa. Thermogravimetric analysis showed decomposition temperature values of 260℃ and 274.7℃ for mcl-PHAWFO and mcl-PHAFFO, respectively. In conclusion, Pseudomonas sp. EML8 and WFO could be suggested as a new candidate and substrate for the industrial production of PHA.