Table 1.

Strain list and polyamine content

Strain designation	References or sources	Mutations in polyamine biosynthetic pathway*	Amine content, μmol/g wet weight†
			Putrescine	Spermidine
71-18	12	None	7	1.2
EWH319	13	Δ(speAspeB) ΔspeC  Δ(speDspeE)	0‡	0‡
HT306	11	Δ(speAspeB) ΔspeC  Δ(speDspeE)cadA	0‡	0‡
EWH319/pDT1.5	This study§	Δ(speAspeB) ΔspeC  Δ(speDspeE)	¶	¶
HT551	14	Δ(speDspeE)	12	0‡

^*speA, arginine decarboxylase; speB, agmatine ureohydrolase; speC, ornithine decarboxylase; speD, S-adenosylmethionine decarboxylase; speE, spermidine synthase (putrescine aminopropyltransferase). 

^† The cells used for these assays were grown in polyamine-deficient VB medium to an OD₆₀₀ of 0.4–0.5, collected by centrifugation, and extracted with 5% trichloroacetic acid. The supernatant was assayed for putrescine and spermidine by HPLC chromatography (14). 

^‡ Not detected by HPLC analysis. 

^§ JI171, an E. coli strain containing pDT1.5 overexpressing E. coli Mn-SOD (sodA) (6), was kindly provided by J. Imlay (University of Illinois, Urbana). Plasmid DNA was isolated and used to transform EWH319 with standard procedures. 

^¶ Not determined.