Growth medium

About: Growth medium is a research topic. Over the lifetime, 1889 publications have been published within this topic receiving 59171 citations. The topic is also known as: culture medium & culture media.

A serum factor requirement for the passage of cultured Vero cells through G2.

Abstract: When Vero cells, a line derived from and African Green Monkey kidney, are grown under conditions where the saturation density is limited by serum, they deplete the growth medium of a factor necessary for cell division. The factor is a component of serum. When Vero cells are plated at low density (2 X 10(4)/cm2) in this depleted growth medium (after dialysis against serum-free Dulbecco's Modified Eagle's Medium) they initiate an unbalanced program of growth. Protein synthesis proceeds at the same rate as parallel cells in fresh serum, and and the cells accumulate protein as a function of time. DNA synthesis is also initiated in these cells, and the amount of DNA per cell increases for the next four days plating. However the cells quickly stop dividing. Measurements of DNA per cell using microspectrofluorometry show that the cells are accumulating in the late S and G2 period during this time. Thus we conclude that these cells cannot pass through a transition point in G2. When fresh serum is added to cells after three days in depleted growth medium, they divide before they begin to synthesize DNA. This further confirms that they are in late S and G2. Cell division is promoted in Vero cells in depleted growth medium by bovine fetuin, and to a lesser extent by bovine albumin. Cell division is not promoted by insulin, hydrocortisone, dexamethasone, linolenic acid, calcium, and typsin inhibitor form ovomucoid. From these data we conclude that transit through G2 requires the prescence of an extracellular factor.

Hinokitiol Production in a Suspension Culture of Calocedrus formosana Florin.

Abstract: A suspension culture of Calocedrus formosana Florin was studied as a material for efficient production of hinokitiol. Murashige-Skoog's medium containing 3% sucrose and 1 mg/l 1-naphthylacetic acid was most desirable for cell growth. Cell growth, expressed as fresh cell weight, showed a 20-fold increase after 4 weeks of culture in this medium. Adding potassium acetate or chitosan to the medium increased hinokitiol production. The highest hinokitiol yield, 1700 μg/g fresh cells, was obtained when cells were cultured in the growth medium with chitosan.

A Modified Growth Medium for Bacillus thuringiensis

Abstract: A published medium for the cultivation of Bacillus thuringiensis was modified for use in high-density fed-batch fermentations. This medium was diagnosed to have a complex nutrient limitation in batch and continuous cultivations. By selective additions of different medium constituents to a chemostat culture, it was established that the limitations were alleviated only by the addition of yeast extract or corn steep liquor ; neither the addition of any salt nor that of individual amino acids influenced the culture behavior. In shake flask cultures, a reduction in glucose concentration and addition of corn steep liquor made the medium carbon-limited ; enrichment with corn steep liquor alone showed dual limitations. These modified media resulted in higher cell densities and showed an increase in the amounts as well as the potency of insecticidal protoxins.

Glycerophosphate as a phosphorus source in a defined medium for Pichia pastoris fermentation

Abstract: Pichia pastoris has emerged as a commercially important yeast for the production of a vast majority of recombinant therapeutic proteins and vaccines The organism can be grown to very high cell densities using a defined basal salts media (BSM) However, BSM contains bi-cation or tri-cation phosphate, which precipitates out of the medium at pH above 55, although the optimal fermentation pH of most recombinant protein fermentation varies between 55 and 70 In this article, the application of glycerophosphates was investigated as a substitute phosphate source in an effort to eliminate precipitation The solubility of BSM containing sodium or potassium glycerophosphates was examined before and after autoclaving at various pHs Sodium glycerophosphate was found stable at autoclave temperature but formed complexes with coexisting magnesium and calcium ions that were insoluble above pH 70 Medium where sodium glycerophosphate was autoclaved separately and then added to the growth medium did not produce any precipitate up to pH 105 The performance of P pastoris fermentations expressing α-galactosidase and ovine interferon-τ using a glycerolphosphate-based medium was found to be comparable to a conventional BSM The results from this work demonstrate that sodium glycerophosphate can be assimilated by the P pastoris strains and can be employed as a reliable phosphorus source for both cell growth and recombinant protein production

Role of L-histidine in conferring tolerance to Ni2+ in Sacchromyces cerevisiae cells

Abstract: Ni2+ toxicity can be alleviated in yeast cells by exogenous L-histidine, but not by its enantiomer, D-histidine, nor by other natural L-amino acids tested. We studied the effect of L-histidine upon the accumulation and intracellular distribution of Ni2+ and found that moderate L-histidine concentrations (less than or equal to those of Ni2+) increased cell tolerance without decreasing Ni2+ accumulation. Although excess L-histidine appeared to lower Ni2+ accumulation, the concomitant presence of Ni2+ and L-histidine in the growth medium stimulated each other’s uptake.