• Title/Summary/Keyword: shake flask

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Thymidine Production by Corynebacterium ammoniagenes Mutants

  • Song, Kyung-Hwa;Kwon, Do-Young;Kim, Sang-Yong;Lee, Jung-Kul;Hyun, Hyung-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.15 no.3
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    • pp.477-483
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    • 2005
  • Corynebacterium ammoniagenes ATCC 6872, which does not accumulate pyrimidine nucleoside or nucleotide, was metabolically engineered to secrete a large amount of thymidine. Characteristics of 5-fluorouracil resistance ($FU^r$), hydroxyurea resistance ($HU^r$), trimethoprim resistance ($TM^r$), thymidylate phosphorylase deficiency ($deoA^-$), inosine auxotrophy ($ino^-$), 5-fluorocytosine resistance ($FC^r$), thymidine kinase deficiency, and thymidine resistance ($thym^r$) were successively introduced into mutant strains KR3 and DY5T9-5, and shake-flask cultures were able to accumulate 408.1 mg/l and 428.2 mg/l of thymidine, respectively, as a major product. The mutant strains did not accumulate thymine at all and accumulated less than 10 mg/l of other pyrimidine nucleosides, such as cytosine, cytidine, and deoxycytidine, as byproducts.

Antimicrobial Activity of Dyed Fabrics with Gromwell Colorants (자초색소를 이용한 염색직물의 항균성)

  • Choi, Hee;Shin, Youn-Sook
    • Korean Journal of Human Ecology
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    • v.5 no.1
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    • pp.42-47
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    • 2002
  • Antimicrobial activity of silk and cotton fabrics dyed with gromwell colorants was examined by shake flask method. The effects of bacterial reduction rate on dye uptake and mordanting were explored. The silk(K/S value 8) and cotton fabric (K/S value 4) dyed with gromwell colorants showed high bacterial reduction rate of 99 % and 88 %, respectively. Post-mordanted silk fabric increased at K/S value, also showed higher bacterial reduction rate than unmordanted. But the effects of antimicrobial activity on mordants showed respectively different results. Pre-mordanted cotton fabric except Sn mordant increased at K/S value, but it was not significant. Pre-mordanted cotton fabric showed significantly higher bacterial reduction rate than unmordanted. Therefore, it was considered that dye uptake of cotton fabric dyed with gromwell colorants and mordants were involved in the bacterial reduction rate. It was concluded that gromwell colorants had antimicrobial activity.

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Functional Finishing of Cotton Fabrics by Treatment with Chitosan

  • Shin, Youn-Sook;Min, Kyung-Hye;Jang, Jeong-In
    • Proceedings of the SOHE Conference
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    • 1997.12a
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    • pp.33-37
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    • 1997
  • Cotton fabric was treated with chitosan solution by pad-dry(-cure) method to impart antimicrobial properties. Four chitosans of different degree of deacetylation(DAC: 65~95%) with similar molecular weight(ca. 50, 000) and one chitosan oligomer(MW 1, 800, DAC 86%) were used. Antimicribial activity against Staphylococcus aureus was evaluated by the Shake Flask Method. Treated fabrics were laundered up to 20 times according to AATCC Test Method 60-1986 and antimicrobial activity of laundered fabrics was evaluated. The antimicrobial activity was increased with the concentration and DAC of chitosan used. And the cured samples showed better durability to laundering than not-cured samples. Crosslinker and binder decreased the antimicrobial activity of fabrics treated with chitosan oligomer and were not effective to improve the durability to washing.

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Studies on Fungal Lipids Containing ${\gamma}$-Linolenic Acid 1. Fatty Acid Composition of Mucor sp. (${\gamma}$-Linolenic acid 함유 곰팡이 지질에 관한 연구 1. Mucor sp.의 지방산 조성)

  • 송권섭;김충기;권용주;양희천;이태규
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.6
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    • pp.636-640
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    • 1990
  • For a studyon the production of ${\gamma}$-linolenic acid(GLA) by fungi 3 fungal strains were isolated from soil. Their cell growth lipid content and fatty acid composition were compared in shake flask culture. Among these fungi the fungus designated as FA-007 has high lipid content(21.1%) and GLA content(15.6% of total fatty acids) The fungal strain FA-007 was tentatively identified as Mucor sp. on the basis of morphological characteristics, Fungal oil produced by this fungus was composed of 75.2% neutral lipid 5.3% glycolipid and 19.5% phospholipid. Although the GLA content in phospholipid was higher than it in neutral lipid the GLA content in neurtal lipid was high as 15.5%.

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Isolation and Cultivation of Microorganism Producing Lipoxygenase Inhibitor (Lipoxygenase Inhibitor를 생산하는 미생물의 분리 및 배양)

  • 황지숙;정영기이태호
    • KSBB Journal
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    • v.8 no.4
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    • pp.375-381
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    • 1993
  • The microorganisms producing a lipoxygenase inhibitor were screened from a wide variety of sources. The isolated strain was assigned to genus Penicillium by its cultural and morphological characteristics. The proper medium for the production of lipoxygenase inhibitor was composed of glucose 3.0%, ammonium sulfate 0.4%, and potassium phosphate (dibasic) 0.1%. The cultivation for lipoxygenase inhibitor production was carried out in 500m1 Erlenmyer flasks containing 100m1 of the medium at $30^{\circ}C$ by cultivating reciprocally. The highest lipoxygenase inhibitor production was observed after 8 days of cultivation. The inhibitor was the low molecular weight substance and inhibited specifically soybean origin lipoxygenase.

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A Study on Cultural Conditions for Acetic Acid Production Employing Pear Juice (배를 이용한 식포의 발효조건에 관한 연구)

  • 오영준
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.4
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    • pp.377-380
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    • 1992
  • To produce economically important acid with pear juice, an acetic acid bacterium was selected from many isolated acetic acid bacteria. The alcohoic fermentation was conducted by inoculating pear juice with Saccharomyces cerevisiae ATCC 4124, and then the pear vinegar was prepared by batch cultivation in flaskes with the isolated Acetobacter sp. The optimum conditions for high yield of acetic acid were studied experimentally in the batch shake flask . For seed purposes the Acetobactor sp. was cultivated for 2 -days and transferred to the acid production medium . Optimum alcohol concentration, initial acidity and temperature for the acid production were 8.0% , 2.0% and 28$^{\circ}C$, respectively. Under the same conditions, the addition of yeast extract (1%) was observed to produce relatively high yield of acetic acid.

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Antibacterial Activity of Ciprofloxacin-incorporated Central Venous Catheters and its Mechanism Against Planktonic Bacterial Cells

  • Jeon, Sung-Min;Kim, Mal-Nam
    • Biomedical Science Letters
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    • v.15 no.1
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    • pp.73-80
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    • 2009
  • Bloodstream infections (BSI) are caused by planktonic microorganisms, sometimes leading to serious infections such as bacteremia and sepsis. BSI occurs more frequently to the patients wearing the central venous catheter (CVC). The ciprofloxacin-incorporated CVC (CFX-CVC) has been reported previously to possess antimicrobial activity. In this study, the antibacterial activity of CFX-CVC and its mechanism against planktonic BSI cells were explored by using the shake flask test and by examining the release rate of 260 nm-absorbing substances from the bacterial cells indicative of the membrane damage of the bacterial cells. CFX-CVC reduced more than 99.9% of the viable planktonic BSI cells demonstrating its potent antibacterial activity. It provoked bacteriolysis causing leakage of a large amount of 260 nm-absorbing materials from the planktonic bacterial cells like S. aureus and E. coli. These results provide evidence that the antibacterial activity of CFX-CVC came from the inhibition of the stability of the planktonic bacterial cells.

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Optimal Culture Conditions for Mycelial Growth and Exo-polymer Production of Ganoderma applanatum

  • Jeong, Yong-Tae;Jeong, Sang-Chul;Yang, Byung-Keun;Islam, Rezuanul;Song, Chi-Hyun
    • Mycobiology
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    • v.37 no.2
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    • pp.89-93
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    • 2009
  • The effect of fermentation parameters and medium composition on the simultaneous mycelial growth and exo-polymer production from submerged cultures of Ganoderma applanatum was investigated in shake-flask cultures. The optimum initial pH for mycelial growth and exo-polymer production was 5.0 and 6.0, respectively. The optimum temperature was $25^{\circ}C$ and the optimum inoculum content was 3.0% (v/v). The optimal carbon and nitrogen sources were glucose and corn steep powder, respectively. After 12 days fermentation under these conditions, the highest mycelial growth was 18.0 g/l and the highest exo-polymer production was 3.9 g/l.

Antimicrobial Finish of Nonwoven Fabric by Treatment with Chitosan (키토산을 이용한 부직포의 항미생물가공)

  • Younsook Shin;Kyunghye Min
    • Textile Coloration and Finishing
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    • v.10 no.3
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    • pp.50-56
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    • 1998
  • Nonwoven fabric was treated with chitosan solution to impart antimicrobial activities by pad-dry method. Antimicrobial activity was measured by Shake Flask Method. Two chitosans of different molecular weight(Mw) with similar degree of deacetylation(DDA) were used : ca. 1,800(chitosan oligomer : DDA 84%) and 180,000(DDA 86%). Chitosan oligomer displayed high antimicrobial activity against P. vulgaris at 0.01%, S. aureus and E. coli at 0.05% treatment concentration, shelving above 90% of reduction rate. Chitosan of Mw 180,000 was effective against S. aureus, E. coil and P. vulgaris at 0.05% treatment concentration, showing almost 100% reduction rate. While chitosan of Mw 180,000 shelved reduction rate above 75% against K. pneumoniae and P. aeruginosa at 0.5% treatment concentration, chitosan oligomer was not effective against them. Fabrics become stiffer and less air permeable as treatment concentration increases. Liquid strike-through time of the sample treated with 0.5% chitosan oligomer solution (3.0 sec) was comparable with a hydrophilic finished sample commercially available(2.6 sec).

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Favorable Conditions for Mycelial Growth of Phellinus linteus (목질진흙버섯(Phellinus linteus)의 적합한 균사생장)

  • Lee, Won-Ho;Kim, Su-Young;Park, Young-Jin;Kim, Tae-Woong;Kim, Ho-Kyung;Sung, Jae-Mo
    • The Korean Journal of Mycology
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    • v.32 no.2
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    • pp.95-100
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    • 2004
  • The main objectives of the study were to investigate cultural characteristics of Phellinus linteus. The optimum culture media for mycelial growth of P. linteus were MYA (malt yeast agar) and SMS (soybean powder malt Sucrose). Similarly, optimum temperature and pH were $30^{\circ}C$ and 6.0, respectively. Malt extract (2%, v/v) and yeast extract (0.2%, v/v) were optimum carbon and nitrogen sources. Similarly, 0.1% $KH_2PO_4$ was optimum mineral salt. Highest mycelial growth was observed when C/N ratio was 10 : 1. Optimum inoculum amount for flask culture was $5{\sim}6$ mycelial discs (6 mm diameter) per 100 ml of liquid medium, Highest mycelial dry weight was obtained when cultured in 100 ml liquid medium in 300 ml shaking flask after 20 days of shaking culture, For mass liquid culture (8 l), flask culture was homogenized and used as an inoculum. Optimum culture period and aeration rate for 8l fermentation culture were 12 days and 2.0 vvm, respectively.