Conditional-suicide containment system for bacteria which mineralize aromatics

Journal Article · Wed May 01 00:00:00 EDT 1991 · Applied and Environmental Microbiology; (United States)

OSTI ID:5383213

Contreras, A; Ramos, J L ^[1]; Molin, S ^[2]

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1. Consejo Superior de Investigaciones Cientificas, Granada (Spain)
2. Technical Univ. of Denmark, Lyngby (Denmark)

A model conditional-suicide system to control genetically engineered microorganisms able to degrade substituted benzoates is reported. The system is based on two elements. One element consists of a fusion between the promoter of the Pseudomonas putide TOL plasmid-encoded meta-cleavage pathway operon (P{sub m}) and the lacI gene encoding Lac repressor plus sylS, coding for the positive regulator of P{sub m}. The other element carries a fusion between the P{sub tac} promoter and the gef gene, which encodes a killing function. In the absence of effectors, expression of the P{sub tac}::gef cassette is no longer prevented and a high rate of cell killing is observed. The substitution of XylS for XylSthr45, a mutant regulator with altered effector specificity and increased affinity for benzoates, allows the control of populations able to degrade a wider range of benzoates at micromolar substrate concentrations. Given the wide effector specificity of the key regulators, the wild-type and mutant ZylS proteins, the system should allow the control of populations able to metabolize benzoate; methyl-, dimethyl-, chloro-, dichloro-, ethyl-, and methoxybenzoates; salicylate; and methyl- and chlorosalicylates. A small population of genetically engineered microorganisms became Gef resistant; however, the mechanism of such survival remains unknown.

• OSTI ID: 5383213
• Journal Information: Applied and Environmental Microbiology; (United States), Vol. 57:5; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AROMATICS
BIODEGRADATION
PSEUDOMONAS
GENETIC ENGINEERING
BENZOIC ACID
BIOLOGICAL PATHWAYS
CELL KILLING
GENE OPERONS
GENES
MUTANTS
PLASMIDS
BACTERIA
BIOTECHNOLOGY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
DECOMPOSITION
MICROORGANISMS
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
540210* - Environment
Terrestrial- Basic Studies- (1990-)