Effects of growth environment on recombinant plasmid stability in Saccharomyces cerevisiae grown in continuous culture

1995 ◽  
Vol 44 (1-2) ◽  
pp. 126-132 ◽  
Author(s):  
R. O'Kennedy ◽  
C. J. Houghton ◽  
J. W. Patching
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Continuous Culture ◽  
Recombinant Plasmid ◽  
Plasmid Stability ◽  
Growth Environment

Histone H1 expressed in Saccharomyces cerevisiae binds to chromatin and affects survival, growth, transcription, and plasmid stability but does not change nucleosomal spacing

1994 ◽  
Vol 14 (4) ◽  
pp. 2822-2835
Author(s):  
C Linder ◽  
F Thoma
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasmid Stability ◽  
Apparent Molecular Weight ◽  
Histone H1 ◽  
Expression Levels ◽  
Inhibition Of Growth ◽  
Gene Coding ◽  
Gal1 Promoter ◽  
Core Histones ◽  
Low Levels

Histone H1 is proposed to serve a structural role in nucleosomes and chromatin fibers, to affect the spacing of nucleosomes, and to act as a general repressor of transcription. To test these hypotheses, a gene coding for a sea urchin histone H1 was expressed from the inducible GAL1 promoter in Saccharomyces cerevisiae by use of a YEp vector for high expression levels (strain YCL7) and a centromere vector for low expression levels (strain YCL1). The H1 protein was identified by its inducibility in galactose, its apparent molecular weight, and its solubility in 5% perchloric acid. When YCL7 was shifted from glucose to galactose for more than 40 h to achieve maximal levels of H1, H1 could be copurified in approximately stoichiometric amounts with core histones of Nonidet P-40-washed nuclei and with soluble chromatin fractionated on sucrose gradients. While S. cerevisiae tolerated the expression of low levels of H1 in YCL1 without an obvious phenotype, the expression of high levels of H1 correlated with greatly reduced survival, inhibition of growth, and increased plasmid loss but no obvious change in the nucleosomal repeat length. After an initial induction, RNA levels for GAL1 and H1 were drastically reduced, suggesting that H1 acts by the repression of galactose-induced genes. Similar effects, but to a lower extent, were observed when the C-terminal tail of H1 was expressed.

Studies in intermicrobial symbiosis. Saccharomyces cerevisiae and Lactobacillus casei

1972 ◽  
Vol 18 (11) ◽  
pp. 1733-1742 ◽  
Author(s):  
R. D. Megee III ◽  
J. F. Drake ◽  
A. G. Fredrickson ◽  
H. M. Tsuchiya
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Continuous Culture ◽  
Mixed Culture ◽  
Growth Medium ◽  
Lactobacillus Casei ◽  
Mixed Cultures ◽  
Genetic Characteristics ◽  
Culture Techniques ◽  
Pure Cultures

Saccharomyces cerevisiae and a riboflavin assay strain of Lactobacillus casei have been propagated anaerobically in mixed culture. Both batch and continuous culture techniques were used. By varying the concentrations of glucose and riboflavin in the growth medium, it was possible to produce symbioses of commensalism + competition, competition, and mutualism + competition. In short, the interaction prevailing is determined by the medium as well as by the genetic characteristics of the organisms. The behavior of the mixed cultures in these situations was predicted from data taken on pure cultures of the organisms.

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