PMID:4577939

Citation	Kusch, M and Wilson, TH (1973) Defective lactose utilization by a mutant of Escherichia coli energy-uncoupled for lactose transport. The advantages of active transport versus facilitated diffusion.Biochim. Biophys. Acta 311:109-22
Abstract	No abstract in PubMed
Links	PubMed
Keywords	Biological Transport; Biological Transport, Active; Carbon Isotopes; Cell Division; Densitometry; Diffusion; Disaccharides; Enzyme Induction; Escherichia coli; Galactosidases; Kinetics; Lactose; Mutation; Transduction, Genetic
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Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

• Parent Strain: X71 (i^-z⁺y⁺a^-, proC^-, try^-, B₁^-)
• Additional Strain: X71-54 (i^-z⁺y^UNa^-)- energy uncoupled mutant
• Additional Strain: X71-15 (i⁺z⁺y⁺a^-)
• Additional Strain: X9003 (i⁺z^-y⁺a⁺, B₁^-)
• Additional Strain: 54-41 (i⁺z⁺y^UNa^-)

• Additional Strain: 316 (i^-z⁺y^-a^-)- y^- strain

• β-galactosidase assay
• α-galactosidase assay
• Carrier-mediated transport assay
• thiogalactoside transacetylase activity was determined

• P₁ Transduction

Phenotype Annotations

Species	Taxon ID	Strain	Gene (if known)	OMP	Phenotype	Details	Evidence	Notes
Escherichia coli	NCBI:562	X71-54	lacYUN	inability to grow on lactose	Growth	in a minimal salts medium	Other	in text, pg. 113
Escherichia coli	NCBI:562	316	lacY-	no induction of alpha-galactosidase	Metabolic Activity	alpha-gal activity	Biochemical Assay	in text- pg. 116
Escherichia coli	NCBI:562	54-41	lacYUN	White colonies on MacConkey melibiose indicator plates	Growth	inability to ferment 0.2% melibiose	Plating Assay	Table 4
Escherichia coli	NCBI:562	54-41	lacYUN	reduced intracellular IPTG accumulation	Other	mutant reached a maximum intracellular concentration of 0.1 mM compared to 0.4 mM IPTG for the energy-coupled parent	Other	Figure 1- [14C]IPTG uptake
Escherichia coli	NCBI:562	54-41	lacYUN	reduced rate of beta-galactosidase induction	Metabolic Activity		Biochemical Assay	Figure 4- beta-galactosidase activity measured after lactose induction
Escherichia coli	NCBI:562	X71-54	lacYUN	reduced growth rate on melibiose	Growth	in a minimal salts medium	Plating Assay	Table 3
Escherichia coli	NCBI:562	X71-54	lacYUN	reduced rate of alpha-galactosidase induction	Metabolic Activity		Biochemical Assay	Figure 5- alpha-galactosidase activity measured after melibiose induction
Escherichia coli	NCBI:562	54-41	lacYUN	decreased affinity for lactose	Other		Other	Table 5- kinetics of transporter for potential inducer molecules
Escherichia coli	NCBI:562	54-41	lacYUN	Light pink colonies on MacConkey lactose indicator plates	Growth	reduced ability to ferment 0.2% lactose (fully restored when IPTG is present)	Plating Assay	Table 4
Escherichia coli	NCBI:562	X71-54	lacYUN	Light pink colonies on MacConkey melibiose indicator plates	Growth	inability to ferment 0.2% melibiose	Plating Assay	Table 4
Escherichia coli	NCBI:562	X71-54	lacYUN	Light pink colonies on MacConkey melibiose indicator plates	Growth	reduced ability to ferment 0.2% melibiose	Plating Assay	Table 4
Escherichia coli	NCBI:562	54-41	lacYUN	no growth on lactose	Growth	in liquid culture with lactose concentrations b/t 5M and 50mM	Plating Assay	in text, pg. 117- addition of 0.5mM IPTG added to lactose medium lead to growth comparable to parent with no constitutive cells
Escherichia coli	NCBI:562	54-41	lacYUN	increased affinity for melibiose	Other		Other	Table 5- kinetics of transporter for potential inducer molecules
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