• Title/Summary/Keyword: microbial cell growth

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Quality Characteristics of Makgeolli during Freezing Storage (냉동저장에 따른 막걸리의 품질특성)

  • Lee, Jin-Won;Shim, Jae-Yong
    • Food Engineering Progress
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    • v.14 no.4
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    • pp.328-334
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    • 2010
  • Recently the enhancement and development of makgeolli processing to extend shelf life are constantly accomplished. However, the standardization to restrict microorganisms including cold chain system and sterilizing system has not been established yet. Therefore, the objective of this study was to investigate the storage stability of makgeolli using quick freezing (QF) and slow freezing (SF) storage methods. The storage period was 40 days. Every 10 days, the samples were taken from the quick and slow freezing storage chamber. And then the samples were put into a $10^{\circ}C$ refrigerator for 24 hr to thaw them. The final samples were evaluated for chemical experiments and microbial cell counts. As a result, reducing sugar content was dramatically increased after 10 days for all of the samples. In titratable acidity and color values case, these values did not significantly change by storage time. In case of lactic acid bacteria and yeasts for all the samples, there was a decreasing tendency with storage time. Especially, in case of lactic acid bacteria, the changes from the beginning microbial cell counts ($4.1{\times}10^7$ CFU/mL) for QF and SF after 20 days were $3.6{\times}10^6$ CFU/mL and $1.8{\times}10^4$ CFU/mL, respectively. This result showed that the freezing methods could restrict the microbial growth in makgeolli.

Rapid and exact molecular identification of the PSP (paralytic shellfish poisoning) producing dinoflagellate genus Alexandrium

  • Kim, Choong-jae;Kim, Sook-Yang;Kim, Kui-Young;Kang, Young-Sil;Kim, Hak-Gyoon;Kim, Chang-Hoon
    • Proceedings of the Korean Aquaculture Society Conference
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    • 2003.10a
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    • pp.132-133
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    • 2003
  • The marine dinoflagellate genus Alexandrium comprise PSP producing A. acatenella, A. angustitabuzatum, A. catenella, A. fundyense, A. minutum, A. ostenfezdii, A. tamiyavanichii and A. tamarense. In monitoring toxic Alexandrium, rapid and exact species identification is one of the significant prerequisite work, however we have suffered confusion of species definition in Alexandrium. To surmount this problem, we chose DNA probing, which has long been used as an alternative for conventional identification methods, primarily relying on morphological approaches using microscope in microbial field. Oligonucleotide DNA probes targeting rRNA or rDNA have been commonly used in diverse studies to detect and enumerate cells concerned as a culture-indetendent powerful tool. Despite of the massive literature on the HAB species containing Alexandrium, application of DNA probing for species identification and detection has been limited to a few documents. DNA probes of toxic A. tamarense, A. catenella and A. tamiyavanichii, and non-toxic A. affine, A. fraterculus, A. insuetum and A. pseudogonyaulax were designed from LSU rDNA D1-D2, and applied to whole cell-FISH. Each DNA probes reacted only the targeted Alexandrium cells with very high species-specificity within Alexandrium. The probes could detect each targeted cells obtained from the natural sea water samples without cross-reactivity. Labeling intensity varied in the growth stage, this showed that the contents of probe-targeted cellular rRNA decreased with reduced growth rate. Double probe TAMID2S1 achieved approximately two times higher fluorescent intensity than that with single probe TAMID2. This double probe did not cross-react with any kinds of microorganisms in the natural sea waters. Therefore we can say that in whole-cell FISH procedure this double DNA probe successfully labeled targeted A. tamiyavanichii without cross-reaction with congeners and diverse natural bio-communities.

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Comparison of Biological Activities of Fermented Codonopsis lanceolata and Fresh Codonopsis lanceolata (생더덕과 발효더덕의 유용생리활성 비교)

  • Kim, Seung-Seop;Ha, Ji-Hye;Jeong, Myoung-Hoon;Ahn, Ju-Hee;Yoon, Won-Byung;Park, Sung-Jin;Seong, Dong-Ho;Lee, Hyeon-Yong
    • Korean Journal of Medicinal Crop Science
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    • v.17 no.4
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    • pp.280-285
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    • 2009
  • Both fresh Codonopsis lanceolata and lactic acid bacteria fermented Codonopsis lanceolata were extracted with water at $100^{\circ}C$, and tested for anticancer activity using several human cancer cell lines. The fermented extracts inhibited the growth of hepatocellular carcinoma cells up to 90%, compared to 75% for fresh Codonopsis lanceolata. The extracts of cytotoxicity on human normal lung cells (HEK293) were as low as 15%. Especially, human hepatocellular carcinoma cell were more efficiently inhibited than other cells. This extract also inhibited $\alpha$-glucosidase activity up to 60% at 1.0mg/$m{\ell}$. This fermented extracts showed the inhibition potency on tyrosinase by 25% at 1.0mg/$m{\ell}$. From the results, the fermented Codonopsis lanceolata enhanced several biological activities up to $20{\sim}30%$, compared to those from fresh Codonopsis lanceolata. It implies that fermentation process could be one of useful methods of utilizing low quality Codonopsis lanceolata. Because this process could yield high amounts of biologically active compounds by the help of microbial growth.

Development of an Integrated Calorimeter Using Temperature Control Signals of a Bioreactor and On-line Measurement of Metabolic Heat of a Microbial Cultivation (발효조의 온도제어 신호를 이용한 직접열량계의 개발 및 대사열량의 온라인 측정)

  • Hong, Geon-Pyo;Heo, Won
    • KSBB Journal
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    • v.14 no.5
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    • pp.543-549
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    • 1999
  • For development of an integrated calorimetric bio-reactor to measure the metabolic heat dissipated during cell growth, a 5 liter jar fermenter was modified to measure the pulse length of automatic temperature control signals to set heater on and off, and the to send them to computer to calculate the cumulative heat supplied. Cumulative heats for the calorimetric reactor in the absence of cell growth, were measured with varying conditions. The heat loss by the aeration was 30.9 kJ/vvm and the loss to ambient air was 10.5 kJ/L/hr/$^{\circ}C$. Cumulative heat was measued within $\pm$0.2% when testing with a small electri heater submerged in the reactor. Metabolic heat was measured to be 0.76 and 0.76 and 11.4kJ per g consumption of glucose during cultivation of S. cerevisiae and E. coli, respectively.

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Streptomyces griseus HH1, An A-factor Deficient Mutant Produces Diminished Level of Trypsin and Increased Level of Metalloproteases

  • Kim, Jung-Mee;Hong, Soon-Kwang
    • Journal of Microbiology
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    • v.38 no.3
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    • pp.160-168
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    • 2000
  • A-factor I a microbial hormone that can positively control cell differentiation leading to spore formation and secondary metabolite formation in Streptomyces griseus. to identify a protease that is deeply involved in the morphological and physiological differentiation of Streptomyces, the proteases produced by Streptomyces griseus IFO 13350 and its A-factor deficient mutant strain, Streptomyces griseus HH1, as well as Streptomyces griseus HH1 transformed with the afsA gene were sturdied. In general Streptomyces griseus showed a higher degree of cell growth and protease activity in proportion to its ability to produce a higher amount of A-factor. In particular, the specific activity of the trypsin of Streptomyces griseus IFO 13350 was greatly enhanced more than twice compared with that of Streptomyces griseus HH1 in the later stage of growth. The specific activity of the metalloprotease of Streptomyces griseus HH1 was greatly enhanced more than twice compared with that of Streptomyces griseus IFO 13350, and this observation was reversed in the presence of thiostreptione, However, Streptomyces griseus HH1 transformed with the afsA gene showed a significantly decreased level of trypsin and metalloprotease activity compared with that of the HH1 strain. There was no significant difference between Streptomyces griseus IFO 13350 and HH1 strain in their chymotrypsin and thiol protease activity, yet the level of leu-amionpeptidase activity was 2 times higher in Streptomyces griseus HH1 than in strain IFO 13350 . Streptomyces griseus HH1 harboring afsA showed a similar level of enzyme activity , however, all the three protease activities sharply increased and the thiol protease activity was critically increased at the end of the fermentation. When a serine protease inhibitor, pefabloc SC, and metalloprotease inhibitor, EDTA, were applied to strain IFO 13350 to examine the in vivo effects of the protease inhibitors on the morpholofical differentiation, the formation of aerial meycelium and spores was delayed by two or three days.

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Sulforaphane Inhibits Growth of Human Breast Cancer Cells and Augments the Therapeutic Index of the Chemotherapeutic Drug, Gemcitabine

  • Hussain, Arif;Mohsin, Javeria;Prabhu, Sathyen Alwin;Begum, Salema;Nusri, Qurrat El-Ain;Harish, Geetganga;Javed, Elham;Khan, Munawwar Ali;Sharma, Chhavi
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5855-5860
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    • 2013
  • Phytochemicals are among the natural chemopreventive agents with most potential for delaying, blocking or reversing the initiation and promotional events of carcinogenesis. They therefore offer cancer treatment strategies to reduce cancer related death. One such promising chemopreventive agent which has attracted considerable attention is sulforaphane (SFN), which exhibits anti-cancer, anti-diabetic, and anti-microbial properties. The present study was undertaken to assess effect of SFN alone and in combination with a chemotherapeutic agent, gemcitabine, on the proliferative potential of MCF-7 cells by cell viability assay and authenticated the results by nuclear morphological examination. Further we analyzed the modulation of expression of Bcl-2 and COX-2 on treatment of these cells with SFN by RT-PCR. SFN showed cytotoxic effects on MCF-7 cells in a dose- and time-dependent manner via an apoptotic mode of cell death. In addition, a combinational treatment of SFN and gemcitabine on MCF-7 cells resulted in growth inhibition in a synergistic manner with a combination index (CI)<1. Notably, SFN was found to significantly downregulate the expression of Bcl-2, an anti-apoptotic gene, and COX-2, a gene involved in inflammation, in a time-dependent manner. These results indicate that SFN induces apoptosis and anti-inflammatory effects on MCF-7 cells via downregulation of Bcl-2 and COX-2 respectively. The combination of SFN and gemcitabine may potentiate the efficacy of gemcitabine and minimize the toxicity to normal cells. Taken together, SFN may be a potent anti-cancer agent for breast cancer treatment.

Evaluation and cloning of a (R)-stereospecific esterase from Bacillus stearothermophilus JY144

  • Kim, Ji-Yeon;Kim, Yun-Jeong;Choe, Gi-Seop;Kim, Geun-Jung;Yu, Yeon-U
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.457-460
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    • 2002
  • In an effort to isolate novel strains expressing a thermostable esterase that hydrolyzed the rac-ketoprofen ethyl ester to ketoprofen in the stereospecific manner, we screened various soils and composts from broad ecological niches in which the activity was expected to be found. Three hundreds of microbial strains were tested to determine their ester-hydrolyzing activity by using an agar plate containing insoluble tributyrin as an indicative substrate, and then further screened by activity on the (R,S)-ketoprofen ethyl ester. Twenty-six strains were screened primarily at high growth and incubation temperature and further compared the ability to ethyl ester-hydrolyzing activity in terms of conversion yield and chiral specificity. Consequently, a strain JYl44 was isolated as a novel strain that produced a (R)-stereospecific esterase with high stability and systematically identified as a Bacillus stearothermophilus JY144. The enzyme indeed stables at a broad range of temperature, upto 65 $^{\circ}C$, and pH ranging from 6.0 to 10.0. The optimal temperature and pH for enzymatic conversion were 50 $^{\circ}C$ and 9.0, respectively. Based on the observations that resulted a poor cell growth, and enzyme expression in wild type strain, we further attempted the gene cloning into a general host Escherichia coli and determined its primary structure, concomitantly resulting a high level expression of the enzyme. The cloned gene had an open reading frame (250 amino acids) with a calculated molecular mass of 27.4 kDa, and its primary structure showed a relative high homology (45-52 %) to the esterases from Streptomyces and Bacillus strains. The recombinant whole cell enzyme could efficiently convert the rac-ketoprofen ethyl ester to (R)-ketoprofen, with optical purity of 99 % and yield of 49 %.

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Induction of Apoptosis by Ethanol Extract of Lythrum anceps (Koehne) Mak ino in Human Leuk emia U937 Cells (인체백혈병 U937 세포에서 부처꽃 에탄올추출물에 의한 apoptosis 유도)

  • Eun Jung Ahn;Chul Hwan Kim;Jin-Woo Jeong;Buyng Su Hwang;Min-Jeong Seo;Kyung-Min Choi;Su Young Shin
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2020.08a
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    • pp.77-77
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    • 2020
  • Purple loosestrife-Lythrum anceps (Koehne) Makino is a herbaceous perennial plant belonging to the Lythraceae family. It has been used for centuries in Korea and other Asian traditional medicine. It has been showed pharmacological effects, including anti-oxidant and anti-microbial effects. However, the mechanisms underlying its anti-cancer mechanisms are not yet understood. In this study, we investigated the mechanism of apoptosis signaling pathways by ethanol extract of Lythrum anceps (Koehne) Makino (ELM) in human leukemia U937 cells. Treatment with ELM significantly inhibited cell growth in a dose-dependent manner by inducing apoptosis, as evidenced by the formation of apoptotic bodies (ApoBDs), DNA fragmentation and increased populations of sub-G1 ratio. Induction of apoptosis by ELM was connected with up-regulation of death receptor (DR) 4 and DR5, pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic Bcl-2 protein, and inhibitor of apoptosis protein (IAP) family proteins (XIAP, cIAP-1, survivin), depending on dosage. This induction was associated with Bid truncation, mitochondrial dysfunction, proteolytic activation of caspases (-3, -8 and -9) and cleavage of poly(ADP-ribose) polymerase protein. Therefore, our data indicate that ELM suppresses U937 cell growth by activating the intrinsic and extrinsic apoptosis pathways, and thus may have applications as a potential source for an anti-leukemic chemotherapeutic agent.

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Environmental resistance of indigenous Saccharomyces cerevisiae with tolerance to potassium metabisulfite at the microbial succession stage of fermenting Campbell Early grape (캠벨얼리 와인발효 중 효모 천이단계에서 분리된 아황산 내성 토착형 효모의 환경내성)

  • Kim, Mi-Sun;Hong, Young-Ah;Yeo, Soo-Hwan;Baek, Seong-Yeol;Yun, Hye-Ju;Rhee, Chang-Ho;Kim, Kwan-Pil;Park, Heui-Dong
    • Food Science and Preservation
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    • v.20 no.6
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    • pp.886-893
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    • 2013
  • Several indigenous sulfite-resistant yeasts were isolated at the microbial succession stage of yeast flora during spontaneous fermentation of Campbell Early grapes using a YPD plate that contained 200 mg/L or 500 mg/L potassium metabisulfite. When they were applied to the wine fermentation using the Campbell Early grape and apple juices, strains S13 and D8 showed strong alcohol fermentation and good flavor production. They were identified as Saccharomyces cerevisiae in the phylogenetic analysis based on their ITS 1-5.8S-ITS II DNA sequences. The two yeast strains grew to a high cell density in the YPD media supplemented with 40%(w/v) glucose. They also grew rapidly in the YPD media at $40^{\circ}C$. While strain S13 showed some differences in cell density at the two temperatures, no marked difference was observed during the culture of strain D8. The strains grew relatively well at pH 5.0 and 9.0 compared with pH 7.0, which was the optimum pH for their growth. Especially, strain S13 cultivated in the YPD media at pH 9.0 grew to 93% of the growth of strain D8, which was obtained at pH 7.0.

Isolation and Characterization of Acid Protease Produced by Staphylococcus sp. CB2-3 from Digestive Organ of Harmonia axyridis (무당벌레 소화기관으로부터 산성 단백질 분해효소를 생산하는 Staphylococcus sp. CB2-3의 분리 및 특성)

  • Kim, Se-Jong;Whang, Kyung-Sook
    • Korean Journal of Microbiology
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    • v.47 no.3
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    • pp.255-262
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    • 2011
  • Six protein-degrading bacteria were isolated from digestive organ of Harmonia axyridis. These isolates were categorized as Staphylococcus sciuri subsp. sciuri (3 strains), Bacillus subtilis (1 strain), and Bacillus thuringiensis (2 strains) by 16S rRNA gene sequence analysis. The Staphylococcus sp. CB2-3 was selected as a protease-producing bacterium which showed the highest protease activity of 58.5 U/ml at the pH 5.0 medium. The optimal pH and temperature of protease activity were pH 5.0 and $40^{\circ}C$, respectively. This acid protease had a relatively high stability of 80% between $30-50^{\circ}C$ at broad temperature range. The opimal medium compositions of carbon, nitrogen and mineral source for cell growth and protease activity were investigated. When sorbitol (0.5%) was used as carbon source, enzyme activity was increased about 2 times than that of the basal medium. When skim milk (0.5%) was used as nitrogen source, activity was increased about 2.5 times than that of the control. Cell growth and enzyme activity were increased by mineral source such as KCl, $K_2HPO_4$, $FeSO_4$, but was completely inhibited by divalent ions such as $Co^{2+}$, $Zn^{2+}$, $Mn^{2+}$, $Cu^{2+}$.