Table 2.

Molecular modifications introduced into genotoxicity reporter strains to enhance sensitivity, expand the response spectrum and incorporate metabolic activation capabilities.

Manipulation	Test	Strain	Modified capabilities	Effect	Reference
uvrAB mutation	SOS Chromotest	PQ37/sfiA::Mud(Ap lac) cts	Deficiency in nucleotide excision repair	Increased sensitivity toward certain genotoxicants	Ames et al. (1973), Baumstark‐Khan et al. (2001), Nunoshiba and Nishioka (1991), El Mzibri et al. (1996), Oda et al. (1985), Quillardet et al. (1982), Østergaard et al. (2007)
	umu‐test	TA1535/umuDC′::lacZ
	GenoTox	TA1535/cda′::gfp
	SOS lux	TA1538/cda′::lux
	VITOTOXTM	TA104/recN2‐4′::lux
	sulA‐test	TA1538/sulA′::lacZ
	Rec‐lac test	KY946 ϕ(recA–lacZ)
tag mutation	SOS‐Chromotest	PQ243/sfiA::Mud(Ap lac) cts	Inactivation of the constitutive 3‐methyl‐adenine DNA glycosylase I	Response to lower concentrations of alkylating agent as MNNG, MMS, etc.	Costa de Oliveira et al. (1987), Quillardet and Hofnung (1993)
oxyR mutation	SOS Chromotest	PQ300/sfiA::Mud(Ap lac) cts	Depletes the oxidative stress responses under the control of OxyR transcription regulator	More sensitive to various classes of peroxides and compounds generating peroxides	Muller and Janz (1992), Quillardet and Hofnung (1993)
rfa mutation	SOS Chromotest	PQ37/sfiA::Mud(Ap lac) cts	Mutation in the core enzymes of lypopolysaccharide (LPS) biosynthesis. Incomplete LPS composed of the ketodeoxyoctanoate‐lipid core.	Higher permeability to substances, especially important with larger hydrophobic genotoxins.	Ames et al. (1973), El Mzibri et al. (1996), Oda et al. (1985), Østergaard et al. (2007), Verschaeve et al. (1999), Quillardet and Hofnung (1985), Rettberg et al. (2001)
	umu‐test	TA1535/umuDC′::lacZ
	GenoTox	TA1535/cda′::gfp
	SOS lux	TA1538/cda′::lux
	VITOTOXTM	TA104/recN2‐4′::lux
	sulA‐test	TA1538/sulA′::lacZ
tolC mutation	GenoTox	N43/cda′::gfpmut3	Inactivation of the efflux, outer membrane transporter‐TolC	Limited efflux capability, increases sensitivity to genotoxins	Davidov et al. (2000), Norman et al. (2005), Rettberg et al. (2001), Maehana et al. (2004)
	SOS lux	PB3/cda′::lux
	recA′::lux	DE112/recA′::lux
	SOSluc	KT1008/umuD′::luc
S. typhimurium NR overexpression	umu‐test	NM1011/umuDC′::lacZ	High nitroreductase activity	Highly sensitive towards many nitroarenes as 2‐NF, 1‐NP, etc.	Oda et al. (1992)
S. typhimurium O‐AT overexpression	umu‐ test	NM2009/umuD′::lacZ	Thirteen‐fold higher isoniazid‐N‐acetyltransferase activity	High sensitivity toward nitro‐ and dinitro‐containing compounds, as wells as arylamins, aminoanzo and HAs.	Oda et al. (1993), Oda et al. (1995)
S. typhimurium O‐AT and NR overexpression	umu‐test	NM3009/umuDC′::lacZ	High O‐AT and NR activity	Increased sensitivity to aromatic amines and nitroarens with/without external MA (S‐9)	Oda et al. (1995), Oda et al. (2004), Østergaard et al. (2007)
	GenoTox	TGO2/cda′::gfp
Human N‐ATs (NAT1 and NAT2) expression in S. typhimurium	umu‐test	NM6001/umuDC′::lacZ	N‐acetyltransferase 1 or N‐acetyltransferase 2 activity	Increased sensitivity to aromatic amines and heterocyclic aromatic amines	Oda et al. (1999)
		NM6002/umuDC′::lacZ
Human CYP1A2 and NADPH–P450 reductase expression in S. typhimurium	umu‐test	OY1001/umuDC′::lacZ	7‐Ethoxyresorufin O‐de‐ethylation and NADPH–cytochrome c reductase activity	Detection of some carcinogenic HAs, without the addition of metabolic activation system (S‐9)	Aryal et al. (1999)
Human CYP1A2 and NADPH–P450 reductase with O‐AT expression in S. typhimurium	umu‐test	OY1002/umuDC′::lacZ	7‐Ethoxyresorufin O‐de‐ethylation and NADPH–cytochrome c reductase activity, joint with high O‐AT activity	More sensitive to HAs than the previous strain, with ought external MA. Detects the mutagens APNH and APH.	Aryal et al. (2000), Oda et al. (2004)

CYP1A2, cytochrome P450 1A2; O‐AT, O‐acetyltransferase; NR, nitroreductase; N‐AT, N‐acetyltransferase; HA, hetrocyclic amines; MA, metabolic activation; APNH, aminophenylnorharman; APH, aminophenylharman.