scholarly journals Comparative Study of the Effects of Various Culture Conditions on Cell Growth and Gagaminine Synthesis in Suspension Culture of Cynanchum wilfordii (MAXIM.) HEMSLEY

2003 ◽  
Vol 26 (9) ◽  
pp. 1321-1325 ◽  
Author(s):  
Ga-Hee Shin ◽  
Man-Gi Chio ◽  
Dae-Won Lee
Keyword(s):  
Cell Growth ◽  
Comparative Study ◽  
Suspension Culture ◽  
Culture Conditions ◽  
Cynanchum Wilfordii

scholarly journals l-Pyroglutamate Spontaneously Formed from l-Glutamate Inhibits Growth of the Hyperthermophilic Archaeon Sulfolobus solfataricus

2001 ◽  
Vol 67 (8) ◽  
pp. 3650-3654 ◽  
Author(s):  
Chan B. Park ◽  
Sun Bok Lee ◽  
Dewey D. Y. Ryu
Keyword(s):  
Cell Growth ◽  
Growth Inhibition ◽  
Yeast Extract ◽  
Formation Rate ◽  
Sulfolobus Solfataricus ◽  
Methionine Sulfoxide ◽  
Inhibitory Effect ◽  
Culture Conditions ◽  
Culture Broth ◽  
Cell Growth Inhibition

ABSTRACT Identification of physiological and environmental factors that limit efficient growth of hyperthermophiles is important for practical application of these organisms to the production of useful enzymes or metabolites. During fed-batch cultivation of Sulfolobus solfataricus in medium containing l-glutamate, we observed formation of l-pyroglutamic acid (PGA). PGA formed spontaneously from l-glutamate under culture conditions (78°C and pH 3.0), and the PGA formation rate was much higher at an acidic or alkaline pH than at neutral pH. It was also found that PGA is a potent inhibitor of S. solfataricus growth. The cell growth rate was reduced by one-half by the presence of 5.1 mM PGA, and no growth was observed in the presence of 15.5 mM PGA. On the other hand, the inhibitory effect of PGA on cell growth was alleviated by addition of l-glutamate or l-aspartate to the medium. PGA was also produced from the l-glutamate in yeast extract; the PGA content increased to 8.5% (wt/wt) after 80 h of incubation of a yeast extract solution at 78°C and pH 3.0. In medium supplemented with yeast extract, cell growth was optimal in the presence of 3.0 g of yeast extract per liter, and higher yeast extract concentrations resulted in reduced cell yields. The extents of cell growth inhibition at yeast extract concentrations above the optimal concentration were correlated with the PGA concentration in the culture broth. Although other structural analogues ofl-glutamate, such as l-methionine sulfoxide, glutaric acid, succinic acid, and l-glutamic acid γ-methyl ester, also inhibited the growth of S. solfataricus, the greatest cell growth inhibition was observed with PGA. We also observed that unlike other glutamate analogues,N-acetyl-l-glutamate enhanced the growth of S. solfataricus. This compound was stable under cell culture conditions, and replacement of l-glutamate with N-acetyl-l-glutamate in the medium resulted in increased cell density.

LDH-A gene suppression affects cell growth of colon carcinoma xenografts but not in culture conditions

2008 ◽  
Vol 6 (9) ◽  
pp. 21-22
Author(s):  
S. Langhammer ◽  
M. Najjar ◽  
K. Berhoerster ◽  
H. Hess-Stumpp ◽  
K.H. Thierauch
Keyword(s):  
Cell Growth ◽  
Colon Carcinoma ◽  
Culture Conditions ◽  
Gene Suppression
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