Biomaterial Database

Temperature induction of bacteriophage lambda mutants in Escherichia coli. 1995

B Y Chen, and C S Lin, and H C Lim

Department of Chemical and Biochemical Engineering, School of Engineering, University of California, Irvine 92717, USA.

The paper presents temperature induction in Escherichia coli cells with phage lambda on the target-protein production and cell growth. Replicated lambda-DNA particles in the Q- and S- mutants remain naked for a longer time by preventing DNA packaging and cell lysis, and therefore the expression of the foreign genes is high. However, the parasitic infection of phage-lambda causes on significant losses of host cell viability in the induction phase. The temperature effects on cell growth and targeted-gene product formation were investigated. Gene amplification was found to be growth phase dependent for both Qam73 (Q mutation) and Sam100 (S mutation) mutants. Maximum induction occurs in the early exponential phase and under the optimal cell density. The total beta-galactosidase activity at this optimal induction condition increases roughly 8-10-fold with respect to that without thermal induction. To maximize the induction efficiency for the gene-product beta-galactosidase activity, several operating parameters were investigated. In this study, temperature induction is strongly dependent upon the population density of 'susceptible' cells at which time the temperature is shifted to 38-42 degrees C. This may be due to the 'threshold' population density to regulate the infection of lambda to hosts and control the productivity of target gene expression.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008242	Lysogeny	The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.	Integration, Prophage,Prophage Integration,Integrations, Prophage,Prophage Integrations
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010582	Bacteriophage lambda	A temperate inducible phage and type species of the genus lambda-like viruses, in the family SIPHOVIRIDAE. Its natural host is E. coli K12. Its VIRION contains linear double-stranded DNA with single-stranded 12-base 5' sticky ends. The DNA circularizes on infection.	Coliphage lambda,Enterobacteria phage lambda,Phage lambda,lambda Phage
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D001616	beta-Galactosidase	A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.	Lactases,Dairyaid,Lactaid,Lactogest,Lactrase,beta-D-Galactosidase,beta-Galactosidase A1,beta-Galactosidase A2,beta-Galactosidase A3,beta-Galactosidases,lac Z Protein,Protein, lac Z,beta D Galactosidase,beta Galactosidase,beta Galactosidase A1,beta Galactosidase A2,beta Galactosidase A3,beta Galactosidases
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures