Thiophene-degrading Escherichia coli mutants possess sulfone oxidase activity and show altered resistance to sulfur-containing antibiotics

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Applied and Environmental Microbiology; (United States)

OSTI ID:5324062

Juhl, M J; Clark, D P ^[1]

---

1. Southern Illinois Univ., Carbondale (USA)

The authors have previously isolated mutants of Escherichia coli which show increased oxidation of heterocyclic furan and thiophene substrates. They have now found that strains carrying the thdA mutation express a novel enzyme activity which oxidizes a variety of substrates containing a sulfone (e.g., ethyl sulfone) were oxidized. The thdA mutants were more resistant than wild-type strains to aromatic sulfone antibiotics such as dapsone. In contrast they showed increased susceptibility to thiolutin, a cyclic antibiotic containing sulfur at the sulfide level of oxidation. Several new thdA mutant alleles were isolated by selecting for increased oxidation of various aliphatic sulfur compounds. These new thdA mutants showed similar sulfone oxidase activity and the same map location (at 10.7 min) as the original thdA1 mutation. The constitutive fadR mutation was required for the phenotypic expression of thdA-mediated oxidation of sulfur compounds. However, the thdA-directed expression of sulfone oxidase activity was not fadR dependent. The thdC and thdD mutations probably protect against the toxicity of thiophene derivatives rather than conferring improved metabolic capability.

• DOE Contract Number: FG22-87PC79912
• OSTI ID: 5324062
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 56:10; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BACTERIA
BIODEGRADATION
CHEMICAL REACTIONS
DECOMPOSITION
DRUGS
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
GENES
HETEROCYCLIC COMPOUNDS
MICROORGANISMS
MUTANTS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDOREDUCTASES
SULFUR COMPOUNDS
THIOPHENE
TOLERANCE
TOXICITY