Growth of plant cell (Ipomoea) suspension cultures at controlled pH levels

1976 ◽  
Vol 54 (11) ◽  
pp. 1264-1270 ◽  
Author(s):  
S. M. Martin ◽  
Dyson Rose

Suspension cultures of a plant cell line initiated from Ipomoea sp. root tissue were grown in defined medium at controlled pH levels of 4.8, 5.6, 6.4, and 7.1 with ammonium and nitrate as the nitrogen sources. Biomass yield was less at pH 4.8 and 7.1 than at the intermediate pH levels. At pH 7.1, this resulted from the inability of the culture to utilize nitrate. At pH 4.8, the cause of the low yield was not apparent but was probably related to a less efficient utilization of sucrose.The ability of the cells to utilize ammonium increased with increasing pH, with a possible maximum at pH 6.4. The ability to utilize nitrate decreased with increasing pH and was essentially zero at pH 7.1. At pH 4.8, ammonium was released into the medium during part of the growth cycle, indicating that the rate of nitrate reduction exceeded the rate of incorporation of the ammonium thus formed.Utilization of nitrate was not inhibited by the presence of ammonium.

Blood ◽  
1986 ◽  
Vol 67 (6) ◽  
pp. 1542-1549 ◽  
Author(s):  
AF Gazdar ◽  
HK Oie ◽  
IR Kirsch ◽  
GF Hollis

Using a serum-free defined medium, we have established a human cell line, NCI-H929, from a malignant effusion occurring in a patient with IgAk myeloma. The cultured cells have the morphologic, ultrastructural, biochemical, immunologic, and cytochemical features of plasma cells. The cells have rearranged alpha and kappa genes and synthesize and secrete high amounts of IgAk (greater than 80 micrograms/10(6) cells per 24 hours). The cells express surface immunoglobulin (alpha and kappa), the plasma cell antigen PCA-1, the transferrin receptor (T9) and T10 but lack antigens associated with earlier stages of B cell development (HLA-DR, B1, B2, B4, CALLA), as well as other leukocyte- macrophage antigens and Epstein-Barr virus (EBV) nuclear antigen. Although molecular studies confirm that both the tumor and cultured cells are derived from the same clone of malignant B cells, the tumor cells were predominantly near-diploid, whereas the cultured cells are predominantly near-tetraploid with six copies of chromosome 8, four to six of which have an 8q + abnormality. However, both the tumor and the cultured cells have a rearrangement of the cellular c-myc proto- oncogene (located at 8q24) and express c-myc RNA. Although a modest number of human “plasmacytoid” cell lines have been established, most are lymphoblastoid lines lacking plasma cell features, while others appear to be early secretory cells. In contrast, NCI-H929 is a differentiated, highly secretory human plasma cell line.


1979 ◽  
Vol 25 (10) ◽  
pp. 1161-1168 ◽  
Author(s):  
Roselynn M. W. Stevenson

Uptake of amino acids by Bacteroides ruminicola was observed in cells grown in a complete defined medium, containing ammonia as the nitrogen source. A high rate of uptake occurred only in fresh medium, as an inhibitory substance, possibly acetate, apparently accumulated during growth. All amino acids except proline were taken up and incorporated into cold trichloroacetic acid precipitable material. Different patterns of incorporation and different responses to 2,4-dinitrophenol and potassium ferricyanide indicated multiple uptake systems were involved. Kinetic inhibition patterns suggested six distinct systems were present for amino acid uptake, with specificities related to the chemical structures of the amino acids. Thus, the failure of free amino acids to act as sole nitrogen sources for growth of B. ruminicola is not due to the absence of transport systems for these compounds.


1987 ◽  
Vol 7 (10) ◽  
pp. 3740-3748
Author(s):  
C D Woodworth ◽  
H C Isom

A series of simian virus 40 (SV40)-immortalized hepatocyte cell lines were characterized for albumin production, the regulation of albumin production, and the expression of other liver-specific genes. This series of cell lines is particularly useful for studying the regulation of hepatocyte gene expression because the cell lines express liverlike levels of a number of liver-specific functions and do so while growing in a chemically defined medium. SV40-immortalized hepatocyte cell lines were derived from colonies of albumin-producing epithelial cells that arose after primary hepatocytes maintained in chemically defined medium were transfected with SV40 DNA. Some cell lines secreted albumin at levels equal to or greater than those secreted by freshly plated primary hepatocytes, and all but one line continued to produce albumin for more than 20 passages. The variation in albumin secretion among cell lines reflected differences in the amount of albumin produced per cell and not in the percentage of albumin-producing cells in each line. The characterization of selected cell lines showed that albumin production was regulated by cell density during the growth cycle. Albumin production in most cell lines was also regulated by dexamethasone; however, one cell line continued to produce high levels of albumin when the cells were grown in medium lacking dexamethasone, demonstrating that although glucocorticoid can induce albumin production in some cell lines, it is not required for high levels of albumin production by all cells in culture. Regulation of albumin production measured at the level of protein secretion was paralleled by changes in steady-state levels of a 2.3-kilobase albumin RNA. Albumin-producing SV40-immortalized hepatocytes secreted a variety of other plasma proteins, including transferrin, hemopexin, and the third component of complement. These cells also expressed tyrosine aminotransferase activity that was inducible by dexamethasone. Alpha-fetoprotein production was not detected in any of the cell lines examined.


1987 ◽  
Vol 42 (1-2) ◽  
pp. 33-40 ◽  
Author(s):  
Wolfram Förster ◽  
Hans Becker

Abstract Four plant bioregulators were tested for their effects on production of valepotriates in Valeriana wallichii and Fedia cornucopiae cell suspension cultures. Concentrations of more than 10 ppm reduced valepotriate yield. At lower concentrations production was increased. For optimal activity, bioregulators had to be applied during early exponential growth, up to day 8 of the growth cycle. At equimolar concentrations dim ethylm orpholinium bromide (4 ppm) and dimethylpiperidinium chloride (3 ppm) significantly im proved total valepotriates in V. wallichii (up to 23%) and in F cornucupiae (up to 50% ) 2-(3,4-dichlorophenoxy ) - triethylamine (6 ppm ) and 2-(3,5-diisopropylphenoxy)-triethylam ine (6.4 ppm) increased valepotriate production in both cell cultures up to 40%. With dimethylpiperidinium chloride and dimethylmorpholinium bromide the ratio of m onoene to diene valepotriates in both cell systems was significantly shifted to the m onoene com pounds. A general use of these bioregulators to increase production of terpenoid secondary m etabolites in plant tissue cultures is indicated.


Sign in / Sign up

Export Citation Format

Share Document