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Virginia Tech

Heavy Metal Resistance in the Genus Gluconobacter

Abstract

dc:description.abstract

The genus Gluconobacter is industrially important due to the ability to accomplish unusual and almost complete oxidation reactions (bioconversions) and to contaminate high sugar content products. Following preliminary evidence that some strains of Gluconobacter were resistant to cadmium, and realizing that cadmium resistance among gram-negative organisms is often encoded by an operon which also encodes cobalt and zinc resistance via an efflux mechanism, 10 strains of Gluconobacter were tested for heavy-metal resistance. Three of the 10 representative strains appeared to be resistant to cadmium chloride, and two were also resistant to cobalt- and zinc chloride. These strains, as well as two cadmium-sensitive strains were analyzed using PCR and sequencing to establish gene homology with Ralstonia eutropha, the most frequently studied Gram-negative bacterium exhibiting cadmium resistance. Amplification of two genes from the czc operon, known to encode cadmium, cobalt and zinc resistance in Ralstonia, was attempted in the three resistant and two sensitive strains of Gluconobacter. The gene, czcA, thought to encode the main pump protein of the efflux mechanism, was found in all Gluconobacter strains tested. However, amplification of a regulatory gene czcD, thought to sense the extracellular metal ion concentration, was not possible in the Gluconobacter strains tested. The PCR products were sequenced and analyzed for homology to the czc operon in Ralstonia. From the data gathered, it appears as though some strains of Gluconobacter contain at least a portion of the czc operon , encoding cadmium, cobalt and zinc resistance in Ralstonia eutropha.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Biology
Department dc:contributor.department
Biology
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
2000

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Burnley, Leigh-Emma
Chair dc:contributor.committeechair
  • Claus, George William
Committee members dc:contributor.committeemember
  • Yousten, Allan A.
  • Popham, David L.

Subjects

dc:subject × 8

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
etd-12072000-151028
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/35993

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Burnley, Leigh-Emma. Heavy Metal Resistance in the Genus Gluconobacter. masters thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35993